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-rw-r--r--FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/README.md38
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-rw-r--r--FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/README.md26
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-rw-r--r--FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/README.md26
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-rw-r--r--FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/README.md27
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-rw-r--r--FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/README.md34
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-rw-r--r--FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file1_Visualization_of_dz.py59
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-rw-r--r--FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/README.md9
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diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/README.md b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/README.md
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--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/README.md
@@ -0,0 +1,38 @@
+<h1><div align=”center”><b>SubTopic: Critical Points</b></h1></div>
+<br/></br>
+
+<tab>file1_Critical_Point_of_a_function
+
+![file1_Critical_Point_of_a_function](https://github.com/vnb09/FSF-mathematics-python-code-archive/blob/fsf_tasks/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file1_Critical_Point_of_a_function.gif?raw=true)
+<br/></br>
+<br/></br>
+
+<tab>file2_Traces_and_Tangent
+
+![file2_Traces_and_Tangent](https://github.com/vnb09/FSF-mathematics-python-code-archive/blob/fsf_tasks/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file2_Traces_and_Tangent.gif?raw=true)
+<br/></br>
+<br/></br>
+
+<tab>file3_Tangent_plane_at_extrema_of_a_function
+
+![file3_Tangent_plane_at_extrema_of_a_function](https://github.com/vnb09/FSF-mathematics-python-code-archive/blob/fsf_tasks/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file3_Tangent_plane_at_extrema_of_a_function.gif?raw=true)
+<br/></br>
+<br/></br>
+
+<tab>file4_Relative_Maximum_and_Relative_Minimum
+
+![file4_Relative_Maxima_and_Relative_Minima](https://github.com/vnb09/FSF-mathematics-python-code-archive/blob/fsf_tasks/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file4_Relative_Maximum_and_Relative_Minimum.gif?raw=true)
+<br/></br>
+<br/></br>
+
+<tab>file5_Saddle_Point
+
+![file5_Saddle_Point](https://github.com/vnb09/FSF-mathematics-python-code-archive/blob/fsf_tasks/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file5_Saddle_Point.gif?raw=true)
+<br/></br>
+<br/></br>
+
+<tab>file6_f(x,y)=(y-x)(1-2x-3y)
+
+![file6_f(x,y)=(y-x)(1-2x-3y)](https://github.com/vnb09/FSF-mathematics-python-code-archive/blob/fsf_tasks/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file6_f(x%2Cy)%3D(y-x)(1-2x-3y).gif?raw=true)
+<br/></br>
+<br/></br>
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file1_Critical_Point_of_a_function.gif b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file1_Critical_Point_of_a_function.gif
new file mode 100644
index 0000000..ca3989c
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file1_Critical_Point_of_a_function.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file1_Critical_Point_of_a_function.py b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file1_Critical_Point_of_a_function.py
new file mode 100644
index 0000000..e8cb08d
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file1_Critical_Point_of_a_function.py
@@ -0,0 +1,77 @@
+from manimlib.imports import*
+import math as m
+
+#---- case 1: parial derivatives exist at critical point of the function
+class firstScene(ThreeDScene):
+ def construct(self):
+
+ axes = ThreeDAxes()
+ label_x = TextMobject("$x$").shift([5.5,-0.5,0]) #---- x axis
+ label_y = TextMobject("$y$").shift([-0.5,5.5,0]).rotate(-4.5) #---- y axis
+
+ #---- f(x,y) = e^(-10x^2-10y^2)
+ surface = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ m.exp(-10*u**2-10*v**2)
+ ]),u_min = -1, u_max = 1, v_min = -1, v_max = 1, checkerboard_colors = [TEAL_E,TEAL_D,TEAL_C,TEAL_B]).fade(0.6).scale(3.5).shift([0,0,1.5])
+
+ l1 = Line([0,0,3.75],[0,0,0],color = '#800000')
+
+ d = Dot([0,0,3.75],color = '#800000') #---- critical point
+
+ d_text = TextMobject("$\\frac{\\partial f}{\\partial x}=\\frac{\\partial f}{\\partial y} = 0$").scale(0.8).to_corner(UL)
+
+ f_text = TextMobject("Critical Point ",color = YELLOW).shift(3.4*UP).scale(0.5)
+
+ self.set_camera_orientation(phi = 45*DEGREES, theta = 40*DEGREES)
+ self.add(axes)
+ self.add(label_x)
+ self.add(label_y)
+ self.add_fixed_in_frame_mobjects(d_text)
+ self.begin_ambient_camera_rotation(rate = 0.2)
+ self.play(Write(surface))
+ self.wait(1)
+ self.play(Write(l1))
+ self.play(Write(d))
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(f_text)
+ self.wait(3)
+ self.play(FadeOut(f_text),FadeOut(surface),FadeOut(axes),FadeOut(d_text),FadeOut(d),FadeOut(l1),FadeOut(label_x),FadeOut(label_y))
+
+
+#---- case 2: parial derivatives do not exist at critical point of the function
+class secondScene(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes()
+ label_x = TextMobject("$x$").shift([5.5,-0.5,0]) #---- x axis
+ label_y = TextMobject("$y$").shift([-0.5,5.5,0]).rotate(-4.5) #---- y axis
+
+ #---- g(x,y)= |x|+|y|
+ surface = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ abs(u)+abs(v)
+ ]),u_min = -1.5, u_max = 1.5, v_min = -1.5, v_max = 1.5, checkerboard_colors = [TEAL_E,TEAL_D,TEAL_C,TEAL_B])
+
+ d2 = Dot([0,0,0],color = '#800000') #---- critical point
+
+ d2_text = TextMobject("$\\frac{\\partial f}{\\partial x}$ and/or $\\frac{\\partial f}{\\partial y}$ does not exist").scale(0.7).to_corner(UL)
+
+ g_text = TextMobject("Critical Point",color = YELLOW).shift(1.2*RIGHT).scale(0.6)
+
+ self.set_camera_orientation(phi = 60*DEGREES, theta = 40*DEGREES)
+ self.add(axes)
+ self.add(label_x)
+ self.add(label_y)
+ self.add_fixed_in_frame_mobjects(d2_text)
+ self.begin_ambient_camera_rotation(rate = 0.2)
+ self.wait(1)
+ self.play(Write(surface2))
+ self.wait(1)
+ self.play(Write(d2))
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(g_text)
+ self.wait(2)
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file2_Traces_and_Tangent.gif b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file2_Traces_and_Tangent.gif
new file mode 100644
index 0000000..84acf2e
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file2_Traces_and_Tangent.gif
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diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file2_Traces_and_Tangent.py b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file2_Traces_and_Tangent.py
new file mode 100644
index 0000000..4b020e1
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file2_Traces_and_Tangent.py
@@ -0,0 +1,88 @@
+from manimlib.imports import*
+import math as m
+
+#---- tangent to the trace with x constant
+class firstScene(ThreeDScene):
+ def construct(self):
+
+ axes = ThreeDAxes().scale(1)
+ label_x = TextMobject("$x$").shift([5.8,-0.5,0])
+ label_y = TextMobject("$y$").shift([-0.5,-5.6,0]).rotate(-4.5)
+
+ #---- graph of f(x,y) = -x^2-y^2
+ surface = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ -u**2-v**2
+ ]),u_min=-1,u_max=1, v_min=-1,v_max=1,checkerboard_colors=[PURPLE_C,PURPLE_D,PURPLE_E,PURPLE_B]).scale(1.5).shift([0,0,2]).rotate(0.2)
+
+ #---- curve(trace) along y axis
+ curve = ParametricSurface(
+ lambda u, v: np.array([
+ u*0.4,
+ v,
+ -v**2
+ ]),v_min =-1 , v_max =1 , u_min = -0.1, u_max = 0.1).scale(1.6).shift([0.02,0.1,2.3]).set_color("#800000").rotate(0.1)
+
+ d = Dot(color =YELLOW).shift([-0.05,-0.2,2.3]) #---- critical point
+
+ x_text = TextMobject("Tangent to the trace with $x$ constant at critical point").shift(3*RIGHT+2*UP).scale(0.5).to_corner(UL)
+
+ tangent_line = Line([-0.05,-1.5,2.3],[-0.05,1.5,2.3],color = '#228B22')
+
+ self.add(axes)
+ self.set_camera_orientation(phi = 40 * DEGREES, theta = 55 * DEGREES)
+ self.begin_ambient_camera_rotation(rate = 0.1)
+ self.add(label_x)
+ self.add(label_y)
+ self.play(Write(surface))
+ self.add_fixed_in_frame_mobjects(x_text)
+ self.add(curve)
+ self.wait(1)
+ self.play(Write(tangent_line),Write(d))
+ self.wait(1)
+
+
+
+#---- tangent to the trace with y constant
+class secondScene(ThreeDScene):
+ def construct(self):
+
+ axes = ThreeDAxes().scale(1)
+ label_x = TextMobject("$x$").shift([5.8,-0.5,0])
+ label_y = TextMobject("$y$").shift([-0.5,-5.6,0]).rotate(-4.5)
+
+ #---- graph of f(x,y) = -x^2-y^2
+ surface = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ -u**2-v**2
+ ]),u_min = -1, u_max = 1, v_min = -1, v_max = 1, checkerboard_colors = [PURPLE_B,PURPLE_C,PURPLE_D,PURPLE_E]).scale(1.5).shift([0,0,2]).rotate(0.2)
+
+ #---- curve(trace) along x axis
+ curve = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v*0.4,
+ -u**2
+ ]),v_min = -0.1, v_max = 0.1, u_min = -1, u_max = 1).scale(1.6).shift([0.07,0.1,2.3]).set_color("#800000")
+
+ d = Dot(color = YELLOW).shift([0,-0.2,2.3]) #---- critical point
+
+ tangent_line = Line(color = '#228B22').scale(1).shift([0,-0.2,2.3]).rotate(m.radians(190),LEFT)
+
+ y_text = TextMobject("Tangent to the trace with $y$ constant at critical point").shift(3*RIGHT+2*UP).scale(0.5).to_corner(UL)
+
+ self.add(axes)
+ self.set_camera_orientation(phi = 40 * DEGREES, theta = 55 * DEGREES)
+ self.add(label_x)
+ self.add(label_y)
+ self.begin_ambient_camera_rotation(rate = 0.1)
+ self.play(Write(surface))
+ self.add_fixed_in_frame_mobjects(y_text)
+ self.add(curve)
+ self.wait(1.5)
+ self.play(Write(tangent_line),Write(d))
+ self.wait(0.5)
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file3_Tangent_plane_at_extrema_of_a_function.gif b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file3_Tangent_plane_at_extrema_of_a_function.gif
new file mode 100644
index 0000000..14fb318
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file3_Tangent_plane_at_extrema_of_a_function.gif
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diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file3_Tangent_plane_at_extrema_of_a_function.py b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file3_Tangent_plane_at_extrema_of_a_function.py
new file mode 100644
index 0000000..e674113
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file3_Tangent_plane_at_extrema_of_a_function.py
@@ -0,0 +1,73 @@
+from manimlib.imports import*
+
+#---- tangent plane to minima of the function
+class firstScene(ThreeDScene):
+ def construct(self):
+
+ axes = ThreeDAxes()
+ label_x = TextMobject("$x$").shift([5.5,-0.5,0]) #---- x axis
+ label_y = TextMobject("$y$").shift([-0.5,5.5,0]).rotate(-4.5) #---- y axis
+
+ #---- parabola: f(x,y) = x**2 + y**2
+ parabola = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ u**2+v**2
+ ]),v_min = -1, v_max = 1, u_min = -1, u_max = 1, checkerboard_colors = [GREEN_E,GREEN_D,GREEN_C,GREEN_B], resolution = (20, 20)).scale(1)
+
+ d = Dot(np.array([0,0,0]), color = '#800000') # ---- critical point
+
+ tangent_plane = Rectangle(fill_color = '#C0C0C0', fill_opacity = 0.3).move_to(ORIGIN).fade(0.7) # ----tangent plane
+
+ parabola_text = TextMobject("Minimum with horizontal tangent plane").scale(0.7).to_corner(UL)
+
+ self.set_camera_orientation(phi = 75 * DEGREES, theta = 45 * DEGREES)
+ self.begin_ambient_camera_rotation(rate = 0.2)
+ self.add(axes)
+ self.add(label_x)
+ self.add(label_y)
+ self.add_fixed_in_frame_mobjects(parabola_text)
+ self.wait(1)
+ self.play(Write(parabola))
+ self.play(ShowCreation(d))
+ self.wait(1)
+ self.play(ShowCreation(tangent_plane))
+ self.wait(2)
+ self.play(FadeOut(parabola_text),FadeOut(parabola),FadeOut(tangent_plane),FadeOut(d),FadeOut(label_x),FadeOut(label_y),FadeOut(axes))
+
+
+#---- tangent plane to maxima of the function
+class secondScene(ThreeDScene):
+ def construct(self):
+
+ axes = ThreeDAxes()
+ label_x = TextMobject("$x$").shift([5.5,-0.5,0]) #---- x axis
+ label_y = TextMobject("$y$").shift([-0.5,5.5,0]).rotate(-4.5) #---- y axis
+
+ #----parabola: g(x,y) = -x**2-y**2
+ parabola = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ -u**2-v**2
+ ]),v_min = -1, v_max = 1, u_min = -1, u_max = 1, checkerboard_colors = [BLUE_E,BLUE_D,BLUE_C,BLUE_B], resolution = (20, 20)).scale(1)
+
+ d = Dot(np.array([0,0,0]), color = '#800000') #---- critical point
+
+ tangent_plane = Rectangle(fill_color = '#C0C0C0',fill_opacity = 0.3).move_to(ORIGIN).fade(0.7) #---- tangent plane
+
+ parabola_text = TextMobject("Maximum with horizontal tangent plane").scale(0.7).to_corner(UL)
+
+ self.set_camera_orientation(phi = 75 * DEGREES, theta = 45 * DEGREES)
+ self.begin_ambient_camera_rotation(rate = 0.2)
+ self.add(axes)
+ self.add(label_x)
+ self.add(label_y)
+ self.add_fixed_in_frame_mobjects(parabola_text)
+ self.wait(1)
+ self.play(Write(parabola))
+ self.play(ShowCreation(d))
+ self.wait(1)
+ self.play(ShowCreation(tangent_plane))
+ self.wait(2)
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file4_Relative_Maximum_and_Relative_Minimum.gif b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file4_Relative_Maximum_and_Relative_Minimum.gif
new file mode 100644
index 0000000..6b93359
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file4_Relative_Maximum_and_Relative_Minimum.gif
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diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file4_Relative_Maximum_and_Relative_Minimum.py b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file4_Relative_Maximum_and_Relative_Minimum.py
new file mode 100644
index 0000000..3bd810d
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file4_Relative_Maximum_and_Relative_Minimum.py
@@ -0,0 +1,51 @@
+from manimlib.imports import*
+import math as m
+
+#---- locating extrema of a funtion using critical points
+class Extrema(ThreeDScene):
+ def construct(self):
+
+ h_text = TextMobject("Relative Maximum and Relative Minimum",color = GREEN)
+
+ axes = ThreeDAxes()
+ label_x = TextMobject("$x$").shift([5.5,-0.3,0]) #---- x axis
+ label_y = TextMobject("$y$").shift([-0.3,5.5,0]).rotate(-4.5) #---- y axis
+
+ #---- f(x,y) = 5(x+y)e^(-x^2-y^2)
+ surface = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ 5*(u+v)*m.exp(-u**2-v**2)
+ ]),u_min = -PI, u_max = PI, v_min = -PI, v_max = PI).set_color(TEAL).shift([0,0,0]).fade(0.4)
+
+ d1 = Dot(color = YELLOW).shift([0.5,0.5,3.02]) #---- critical point for maxima
+ l1 = Line([0.5,0.5,0.1],[0.5,0.5,3],color = YELLOW)
+
+ d2 = Dot(color = YELLOW).shift([-1.15,0,-2.98]) #---- critical point for minima
+ l2 = Line([-1.15,0,0],[-1.15,0,-2.98],color = YELLOW)
+
+ max_text = TextMobject("Relative Maximum").shift(3.1*UP+1.5*RIGHT).scale(0.5)
+ min_text = TextMobject("Relative Minimum").shift(3.1*DOWN+1.5*LEFT).scale(0.5)
+
+ self.add_fixed_in_frame_mobjects(h_text)
+ self.wait(1)
+ self.wait(1)
+ self.play(FadeOut(h_text))
+ self.wait(1)
+ self.set_camera_orientation(phi = 100*DEGREES, theta = -40*DEGREES)
+ self.add(axes)
+ self.add(label_x)
+ self.add(label_y)
+ self.play(Write(surface))
+ self.wait(1)
+ self.play(Write(l1),Write(d1))
+ self.add_fixed_in_frame_mobjects(max_text)
+ self.wait(1)
+ self.play(Write(l2),Write(d2))
+ self.add_fixed_in_frame_mobjects(min_text)
+ self.wait(1)
+ self.wait(1)
+ self.play(FadeOut(l1),FadeOut(d1),FadeOut(l2),FadeOut(d2),FadeOut(max_text),FadeOut(min_text))
+ self.begin_ambient_camera_rotation(rate = 0.3)
+ self.wait(3)
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file5_Saddle_Point.gif b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file5_Saddle_Point.gif
new file mode 100644
index 0000000..7300f3a
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file5_Saddle_Point.gif
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diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file5_Saddle_Point.py b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file5_Saddle_Point.py
new file mode 100644
index 0000000..67dbb18
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file5_Saddle_Point.py
@@ -0,0 +1,71 @@
+from manimlib.imports import*
+import math as m
+
+#---- saddle point of a function
+class SaddlePoint(ThreeDScene):
+ def construct(self):
+
+ h_text = TextMobject("Saddle Point",color = GREEN)
+
+ axes = ThreeDAxes()
+ label_x = TextMobject("$x$").shift([5.5,-0.3,0]) #---- x axis
+ label_y = TextMobject("$y$").shift([-0.3,5.5,0]).rotate(-4.5) #---- y axis
+
+ #---- f(x,y) = -x^2-y^2
+ surface = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ u**2-v**2
+ ]),u_min = -1, u_max = 1, v_min = -1, v_max = 1,checkerboard_colors = [BLUE_B,BLUE_C,BLUE_D,BLUE_E]).shift([0,0,0]).scale(3)
+
+ #---- curve(trace) along y axis
+ curve_x = ParametricSurface(
+ lambda u, v: np.array([
+ u*0.1,
+ v,
+ v**2
+ ]),v_min = -1, v_max = 1, u_min = -0.2, u_max = 0.2).shift([0,0,-2]).scale(3.1).set_color("#800000").rotate(m.radians(180),UP)
+
+ x_text = TextMobject("A dip at critical point along x axis").scale(0.5).to_corner(UL)
+
+ #---- curve(trace) along x axis
+ curve_y = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v*0.1,
+ -u**2
+ ]),v_min = -0.2, v_max = 0.2, u_min = -1, u_max = 1).scale(3).shift([0.1,0,2.2]).set_color("#800000").rotate(m.radians(182),DOWN)
+
+ y_text = TextMobject("A peak at critical point along y axis").scale(0.5).to_corner(UL)
+
+ d = Dot(color = YELLOW).shift([0,-0.22,0]) #---- critical point(saddle point)
+
+ self.add_fixed_in_frame_mobjects(h_text)
+ self.wait(1)
+ self.play(FadeOut(h_text))
+ self.wait(1)
+ self.set_camera_orientation(phi = 75*DEGREES, theta = 40*DEGREES)
+ self.add(axes)
+ self.add(label_x)
+ self.add(label_y)
+ self.play(Write(surface))
+ self.wait(1)
+ self.move_camera(phi = 45*DEGREES, theta = 70*DEGREES)
+ self.add(curve_y)
+ self.play(Write(d))
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(x_text)
+ self.wait(1)
+ self.wait(1)
+ self.play(FadeOut(curve_y),FadeOut(d),FadeOut(x_text))
+ self.wait(1)
+ self.move_camera(phi = 40*DEGREES, theta = 30*DEGREES)
+ self.add(curve_x)
+ self.play(Write(d))
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(y_text)
+ self.begin_ambient_camera_rotation(rate = 0.3)
+ self.wait(3)
+ self.play(FadeOut(curve_x),FadeOut(d),FadeOut(y_text))
+ self.wait(1)
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file6_f(x,y)=(y-x)(1-2x-3y).gif b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file6_f(x,y)=(y-x)(1-2x-3y).gif
new file mode 100644
index 0000000..4bc92f8
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file6_f(x,y)=(y-x)(1-2x-3y).gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file6_f(x,y)=(y-x)(1-2x-3y).py b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file6_f(x,y)=(y-x)(1-2x-3y).py
new file mode 100644
index 0000000..41c3b61
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical-Points/file6_f(x,y)=(y-x)(1-2x-3y).py
@@ -0,0 +1,29 @@
+from manimlib.imports import*
+
+#---- visualization of the function
+class ExampleAnimation(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes()
+ label_x = TextMobject("$x$").shift([5.5,-0.5,0]) #---- x axis
+ label_y = TextMobject("$y$").shift([-0.5,5.5,0]).rotate(-4.5) #---- y axis
+
+ #---- f(x,y) = (y-x)(1-2x-3y)
+ surface = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ (v-u)*(1-2*u-3*v)
+ ]),v_min = -1, v_max = 1, u_min = -1, u_max = 1, checkerboard_colors = [PURPLE_B,PURPLE_C,PURPLE_D, PURPLE_E]).scale(1).fade(0.2).shift([0.2,0.2,0])
+
+ f_text = TextMobject("$f(x,y) = (y-x)(1-2x-3y)$").to_corner(UL)
+
+ self.set_camera_orientation(phi = 60 * DEGREES, theta = 75 * DEGREES)
+ self.begin_ambient_camera_rotation(rate=0.1)
+ self.add_fixed_in_frame_mobjects(f_text)
+ self.wait(1)
+ self.add(axes)
+ self.add(label_x)
+ self.add(label_y)
+ self.wait(1)
+ self.play(Write(f))
+ self.wait(4)
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/README.md b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/README.md
new file mode 100644
index 0000000..903eaed
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/README.md
@@ -0,0 +1,26 @@
+<h1><div align=”center”><b>SubTopic: Lagrange Multipliers</b></h1></div>
+<br/></br>
+
+<tab>file1_Extrema_over_g(x,y)
+
+![file1_Extrema_over_g(x,y)](https://github.com/vnb09/FSF-mathematics-python-code-archive/blob/fsf_tasks/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/file1_Extrema_over_g(x%2Cy)%3Dk.gif?raw=true)
+<br/></br>
+<br/></br>
+
+<tab>file2_Constraint_circle_with_contour_plot_of_the_surface_x^2+y^2+x^3-y^3
+
+![file2_Constraint_circle_with_contour_plot_of_the_surface_x^2+y^2+x^3-y^3](https://github.com/vnb09/FSF-mathematics-python-code-archive/blob/fsf_tasks/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/file2_Constraint_circle_with_contour_plot_of_the_surface_x%5E2%2By%5E2%2Bx%5E3-y%5E3.gif?raw=true)
+<br/></br>
+<br/></br>
+
+<tab>file3_Geometric_Proof
+
+![file3_Geometric_Proof](https://github.com/vnb09/FSF-mathematics-python-code-archive/blob/fsf_tasks/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/file3_Geometric_Proof.gif?raw=true)
+<br/></br>
+<br/></br>
+
+<tab>file4_Constraints_g_and_h
+
+![file4_Constraints_g_and_h](https://github.com/vnb09/FSF-mathematics-python-code-archive/blob/fsf_tasks/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/file4_Constraints_g_and_h.gif?raw=true)
+<br/></br>
+<br/></br>
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/file1_Extrema_over_g(x,y)=k.gif b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/file1_Extrema_over_g(x,y)=k.gif
new file mode 100644
index 0000000..9a9042f
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/file1_Extrema_over_g(x,y)=k.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/file1_Extrema_over_g(x,y)=k.py b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/file1_Extrema_over_g(x,y)=k.py
new file mode 100644
index 0000000..b7adcc7
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/file1_Extrema_over_g(x,y)=k.py
@@ -0,0 +1,45 @@
+from manimlib.imports import*
+import math as m
+
+#---- optimizing funtion f(x,y) w.r.t to g(x,y)
+class ConstrainedExtrema(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes().scale(0.7).rotate(math.radians(180))
+ label_x = TextMobject("$x$").shift(4*LEFT).fade(0.4) #---- x axis
+ label_y = TextMobject("$y$").shift(3.2*DOWN+0.2*RIGHT).rotate(math.radians(180)).fade(0.4) #---- y axis
+
+ surface = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ u**2+v**2+u**3-v**3
+ ]),u_min=-0.5,u_max=0.5, v_min=-0.5,v_max=0.5).scale(5).shift([0,1,2.5]).set_color(TEAL).fade(0.2)
+
+ c = Circle(color='#FF00FF',fill_opacity=0.3).shift([-0.4,0,1.5]).rotate(1.9,UP).scale(0.7)
+
+ minima = Dot(color = '#4169E1').shift([-0.5,0.5,1]).rotate(1.571,UP)
+ maxima = Dot(color = '#4169E1').shift([0.1,0,2.2]).rotate(1.571,UP)
+
+ max_text = TextMobject("maximum over $g(x,y)=k$",color = '#FFA074').scale(0.6).shift(2.3*UP+2*LEFT)
+ min_text = TextMobject("minimum over $g(x,y)=k$",color = '#FFA074').shift([2.5,0.5,1]).scale(0.6).shift(0.5*UP)
+ label_f = TextMobject("$z=f(x,y)$",color=TEAL).scale(0.8).shift(3*UP+3*RIGHT)
+ label_g = TextMobject("g(x,y)=k",color = PURPLE).scale(0.5).shift(1.5*UP+0.8*LEFT)
+
+
+ self.add(axes)
+ self.add(label_x)
+ self.add(label_y)
+ self.set_camera_orientation(phi=75*DEGREES,theta=45*DEGREES)
+ self.play(Write(surface))
+ self.add_fixed_in_frame_mobjects(label_f)
+ self.wait(2)
+ self.play(Write(c))
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(label_g)
+ self.wait(1)
+ self.play(Write(maxima))
+ self.add_fixed_in_frame_mobjects(max_text)
+ self.wait(1)
+ self.play(Write(minima))
+ self.add_fixed_in_frame_mobjects(min_text)
+ self.wait(1)
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/file2_Constraint_circle_with_contour_plot_of_the_surface_x^2+y^2+x^3-y^3.gif b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/file2_Constraint_circle_with_contour_plot_of_the_surface_x^2+y^2+x^3-y^3.gif
new file mode 100644
index 0000000..d8e03fd
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/file2_Constraint_circle_with_contour_plot_of_the_surface_x^2+y^2+x^3-y^3.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/file2_Constraint_circle_with_contour_plot_of_the_surface_x^2+y^2+x^3-y^3.py b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/file2_Constraint_circle_with_contour_plot_of_the_surface_x^2+y^2+x^3-y^3.py
new file mode 100644
index 0000000..bbbf238
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/file2_Constraint_circle_with_contour_plot_of_the_surface_x^2+y^2+x^3-y^3.py
@@ -0,0 +1,72 @@
+from manimlib.imports import*
+import math as m
+
+#---- contour plot of the surface with constraint circle
+class ContourScene(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes().scale(0.7).rotate(m.radians(180)).fade(0.6)
+ label_x = TextMobject("$x$").shift(4*LEFT).fade(0.4) #---- x axis
+ label_y = TextMobject("$y$").shift(3.2*DOWN+0.2*RIGHT).rotate(m.radians(180)).fade(0.4) #---- y axis
+
+ #---- surface of the function f(x,y) = x^2+y^2+x^3-y^3
+ surface = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ u**2+v**2+u**3-v**3
+ ]),u_min=-0.5,u_max=0.5, v_min=-0.5,v_max=0.5).scale(5).shift([0,-0.5,2.5]).set_color(TEAL).fade(0.5)
+
+
+ #---- contour plots of the surface of the function
+
+ c0 = Circle(color = '#800000').scale(0.5).shift([0,-0.5,0])
+ c1 = Circle(color = '#800000').scale(1).shift([0,-0.5,0])
+ c2 = Circle(color = '#800000').scale(1.5).shift([0,-0.5,0])
+ c3 = Circle(color = '#800000').scale(2).shift([0,-0.5,0])
+ c4 = Circle(color = '#800000').scale(2.5).shift([0,-0.5,0])
+
+ #---- constraint circle
+ circle = Circle(color='#FF00FF',fill_opacity=0.3).shift([-0.5,-1.2,1.5]).rotate(1.9,UP).scale(0.8)
+ circle2 = Circle(color='#FF00FF',fill_opacity=0.3).shift([0.74,0.95,1.5]).rotate(1.9,UP).scale(0.8)
+
+ maxima = Dot(color = '#4169E1').shift([0.7,0.15,1.5]) #---- point of maxima
+ minima = Dot(color = '#4169E1').shift([0.8,1.7,1.5]) #---- point of minima
+
+ min_text = TextMobject("minimum over $g(x,y)=k$",color = '#FFA074').scale(0.6).shift([-2,0.16,1.5])
+ max_text = TextMobject("maximum over $g(x,y)=k$",color = '#FFA074').shift([-2.3,-2.6,1.5]).scale(0.6).shift(0.5*UP)
+
+
+ #---- labelling contour curves
+ label_c0 = TextMobject("1",color = '#FFA074').shift([0.2,0.1,0.5]).scale(0.5)
+ label_c1 = TextMobject("2",color = '#FFA074').shift([0.2,-0.6,0.5]).scale(0.5)
+ label_c2 = TextMobject("3",color = '#FFA074').shift([0.2,-1.1,0.5]).scale(0.5)
+ label_c3 = TextMobject("4",color = '#FFA074').shift([0.2,-1.6,0.5]).scale(0.5)
+ label_c4 = TextMobject("5",color = '#FFA074').shift([0.2,-2.1,0.5]).scale(0.5)
+
+
+ self.set_camera_orientation(phi=75 * DEGREES, theta = 45*DEGREES)
+ self.add(axes)
+ self.add(label_x)
+ self.add(label_y)
+ self.wait(1)
+ self.play(Write(surface))
+ self.play(Write(circle))
+ self.wait(1)
+ self.play(FadeOut(circle))
+ self.wait(1)
+ self.move_camera(phi=0 * DEGREES, theta = 90*DEGREES)
+ self.wait(1)
+ self.play(Write(c0),Write(c1),Write(c2),Write(c3),Write(c4))
+ self.play(FadeOut(surface))
+ self.add_fixed_in_frame_mobjects(label_c0)
+ self.add_fixed_in_frame_mobjects(label_c1)
+ self.add_fixed_in_frame_mobjects(label_c2)
+ self.add_fixed_in_frame_mobjects(label_c3)
+ self.add_fixed_in_frame_mobjects(label_c4)
+ self.wait(1)
+ self.play(Write(circle2))
+ self.wait(1)
+ self.play(Write(minima),Write(maxima))
+ self.add_fixed_in_frame_mobjects(max_text)
+ self.add_fixed_in_frame_mobjects(min_text)
+ self.wait(1)
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/file3_Geometric_Proof.gif b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/file3_Geometric_Proof.gif
new file mode 100644
index 0000000..e028a81
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/file3_Geometric_Proof.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/file3_Geometric_Proof.py b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/file3_Geometric_Proof.py
new file mode 100644
index 0000000..2c1d668
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/file3_Geometric_Proof.py
@@ -0,0 +1,89 @@
+from manimlib.imports import*
+
+#---- visualization of geometric proof of Lagrange multiplier
+class firstScene(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes().scale(0.7).rotate(math.radians(180))
+ label_x = TextMobject("$x$").shift(4*RIGHT).fade(0.4) #---- x axis
+ label_y = TextMobject("$y$").shift(3.2*DOWN+0.2*RIGHT).rotate(math.radians(180)).fade(0.4) #---- y axis
+
+ surface = ParametricSurface(
+ lambda u, v: np.array([
+ 1*np.sin(u)*np.cos(v),
+ 1*np.sin(u)*np.sin(v),
+ -1*np.sin(u)*np.sin(u)+2
+ ]),u_min=0,u_max=PI/2,v_min=0,v_max=2*PI).set_color(GREEN).scale(1).shift([-1.5,-1.5,0])
+
+ d = Dot([-2,-2.55,0],color = '#800000')
+ a_df = Arrow(color = '#00FFFF').rotate(-2).shift(3.2*DOWN+2.3*LEFT) #---- f parallel to g
+ a_dg = Arrow(color = '#FF00FF').scale(0.8).shift(3.2*DOWN+2.3*LEFT).rotate(-2) #---- f parallel to g
+
+ b_dg = Arrow(color = '#00FFFF').rotate(1.1).shift(0.82*LEFT+0.15*UP) #---- f parallel to g
+ b_df = Arrow(color = '#FF00FF').scale(0.6).rotate(-2).shift(1.43*LEFT+1.1*DOWN) #---- f parallel to g
+
+
+ qd = Dot(color = '#800000').shift(1.2*LEFT+0.6*DOWN)
+
+ l1 = Line([-1,-3.1,0],[-4,-3.1,0],color = PINK).rotate(-0.3).fade(0.6)
+ l2 = Line([-0.9,-2.9,0],[-4,-2.9,0],color = PINK).rotate(-0.3).fade(0.6)
+ l3= Line([-0.8,-2.7,0],[-4,-2.7,0],color = PINK).rotate(-0.3).fade(0.6)
+ l4= Line([-0.7,-2.45,0],[-4,-2.45,0],color = PINK).rotate(-0.3).fade(0.6)
+ l5= Line([-0.6,-2.2,0],[-4,-2.25,0],color = PINK).rotate(-0.3).fade(0.6)
+ l6 = Line([-0.5,-2,0],[-4,-2,0],color = PINK).rotate(-0.3).fade(0.6)
+ l7 = Line([-0.4,-1.8,0],[-4,-1.8,0],color = PINK).rotate(-0.3).fade(0.6)
+ l8 = Line([-0.3,-1.6,0],[-4,-1.6,0],color = PINK).rotate(-0.3).fade(0.6)
+ l9= Line([-0.2,-1.4,0],[-4,-1.4,0],color = PINK).rotate(-0.3).fade(0.6)
+ l10= Line([-0.1,-1.2,0],[-4,-1.2,0],color = PINK).rotate(-0.3).fade(0.6)
+ l11 = Line([-0,-1,0],[-4,-1,0],color = PINK).rotate(-0.3).fade(0.6)
+ l12 = Line([-0,-0.8,0],[-4,-0.8,0],color = PINK).rotate(-0.3).fade(0.6)
+ l13= Line([-0,-0.55,0],[-4,-0.55,0],color = PINK).rotate(-0.3).fade(0.6)
+ l14= Line([-0,-0.35,0],[-4,-0.35,0],color = PINK).rotate(-0.3).fade(0.6)
+ l15= Line([-0.,-0.15,0],[-4,-0.15,0],color = PINK).rotate(-0.3).fade(0.6)
+
+ rel_text = TextMobject("$\\nabla f = \\lambda \\nabla g$",color = TEAL).shift([3,3.2,0]).scale(0.5)
+
+ f_text = TextMobject("$\\nabla f$",color = '#800000').shift([1,1,0]).scale(0.5)
+ g_text = TextMobject("$\\nabla g$").shift([1.2,-0.8,0]).scale(0.5)
+
+ p_text= TextMobject("$P$").shift([1.8,2.6,0]).scale(0.5)
+
+ l1_text = TextMobject("$w=$ 17").rotate(math.radians(180)).scale(0.4).shift(2.7*DOWN+4.36*LEFT)
+ l2_text = TextMobject("$w=$ 16").rotate(math.radians(180)).scale(0.4).shift(2.46*DOWN+4.36*LEFT)
+ l3_text = TextMobject("$w=$ 15").rotate(math.radians(180)).scale(0.4).shift(2.2*DOWN+4.36*LEFT)
+ l4_text = TextMobject("$w=$ 14").rotate(math.radians(180)).scale(0.4).shift(1.97*DOWN+4.36*LEFT)
+ l5_text = TextMobject("$w=$ 13").rotate(math.radians(180)).scale(0.4).shift(1.74*DOWN+4.36*LEFT)
+ l6_text = TextMobject("$w=$ 12").rotate(math.radians(180)).scale(0.4).shift(1.5*DOWN+4.36*LEFT)
+ l7_text = TextMobject("$w=$ 11").rotate(math.radians(180)).scale(0.4).shift(1.26*DOWN+4.36*LEFT)
+ l8_text = TextMobject("$w=$ 10").rotate(math.radians(180)).scale(0.4).shift(1.05*DOWN+4.36*LEFT)
+ l9_text = TextMobject("$w=$ 9").rotate(math.radians(180)).scale(0.4).shift(0.8*DOWN+4.32*LEFT)
+ l10_text = TextMobject("$w=$ 8").rotate(math.radians(180)).scale(0.4).shift(0.6*DOWN+4.32*LEFT)
+ l11_text = TextMobject("$w=$ 7").rotate(math.radians(180)).scale(0.4).shift(0.4*DOWN+4.32*LEFT)
+ l12_text = TextMobject("$w=$ 6").rotate(math.radians(180)).scale(0.4).shift(0.2*DOWN+4.32*LEFT)
+ l13_text = TextMobject("$w=$ 5").rotate(math.radians(180)).scale(0.4).shift(-0.02*DOWN+4.32*LEFT)
+ l14_text = TextMobject("$w=$ 4").rotate(math.radians(180)).scale(0.4).shift(-0.23*DOWN+4.32*LEFT)
+ l15_text = TextMobject("$w=$ 3").rotate(math.radians(180)).scale(0.4).shift(-0.44*DOWN+4.32*LEFT)
+
+ level_Curve = VGroup(l1,l1_text,l2,l2_text,l3,l3_text,l4,l4_text,l5,l5_text,l6,l6_text,l7,l7_text,l8,l8_text,l9,l9_text,l10,l10_text,l11,l11_text,l12,l12_text,l13,l13_text,l14,l14_text,l15,l15_text)
+
+ self.set_camera_orientation(phi=0 * DEGREES, theta = 90*DEGREES)
+ self.add(axes)
+ self.add(label_x)
+ self.add(label_y)
+ self.wait(1)
+ self.add(surface)
+ self.wait(1)
+ self.play(ShowCreation(level_Curve))
+ self.wait(1)
+ self.play(ShowCreation(a_df),ShowCreation(a_dg),Write(d))
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(rel_text)
+ self.add_fixed_in_frame_mobjects(p_text)
+ self.wait(1)
+ self.play(Write(qd))
+ self.wait(1)
+ self.play(ShowCreation(b_df))
+ self.add_fixed_in_frame_mobjects(f_text)
+ self.wait(1)
+ self.play(ShowCreation(b_dg))
+ self.add_fixed_in_frame_mobjects(g_text)
+ self.wait(1)
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/file4_Constraints_g_and_h.gif b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/file4_Constraints_g_and_h.gif
new file mode 100644
index 0000000..f1f7974
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/file4_Constraints_g_and_h.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/file4_Constraints_g_and_h.py b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/file4_Constraints_g_and_h.py
new file mode 100644
index 0000000..a1396fc
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Lagrange-Multipliers/file4_Constraints_g_and_h.py
@@ -0,0 +1,52 @@
+from manimlib.imports import*
+import math as m
+
+ class Constraints(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes().rotate(m.radians(75))
+ label_x = TextMobject("$x$").shift([-5.5,1,0]).fade(0.4) #---- x axis
+ label_y = TextMobject("$y$").shift([1,5.5,0]).rotate(-4.5).fade(0.4) #---- y axis
+
+ cylinder = ParametricSurface(
+ lambda u, v: np.array([
+ np.cos(TAU * u),
+ np.sin(TAU * u),
+ 2 * (1-1.5*v)
+ ]),checkerboard_colors=[YELLOW_C,YELLOW_D,YELLOW_E]).shift([0.5,0.5,-0.13]).scale(1)
+
+ plane = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ u+v
+ ]),checkerboard_colors=[TEAL_C,TEAL_D,TEAL_E]).shift([0,0,0]).rotate(m.radians(-40),RIGHT).scale(4).fade(0.3)
+
+ c = Circle(color='#FF00FF',fill_opacity=0.3).shift([0.7,-1.3,0.4]).rotate(2.5,UP).scale(1.32)
+
+ f_text = TextMobject("$f(x,y)=x^2+y^2+z^2$",color = '#FFA074').scale(0.6).to_corner(UL)
+ g_text = TextMobject("$g(x,y)=x^2+y^2+1$",color = '#FFA074').scale(0.6).to_corner(UL)
+ h_text = TextMobject("$h(x,y)=x+y-z=1$",color = '#FFA074').scale(0.6).to_corner(UL)
+
+
+
+ self.set_camera_orientation(phi=65*DEGREES,theta=95*DEGREES)
+
+ self.add(axes)
+ self.add(label_x)
+ self.add(label_y)
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(f_text)
+ self.play(Write(c))
+ self.wait(1)
+ self.play(FadeOut(f_text))
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(g_text)
+ self.play(Write(cylinder))
+ self.wait(1)
+ self.play(FadeOut(g_text))
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(h_text)
+ self.play(Write(plane))
+ self.wait(1)
+ self.play(FadeOut(h_text))
+ self.wait(1)
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical_Points_mcq_questions.pdf b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/MCQ-Questions/Critical_Points_mcq_questions.pdf
index 25c4e4d..25c4e4d 100644
--- a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Critical_Points_mcq_questions.pdf
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/MCQ-Questions/Critical_Points_mcq_questions.pdf
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diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/MCQ-Questions/Lagrange_Multipliers_mcq_questions.pdf b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/MCQ-Questions/Lagrange_Multipliers_mcq_questions.pdf
new file mode 100644
index 0000000..3ba7d1c
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+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/MCQ-Questions/Lagrange_Multipliers_mcq_questions.pdf
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diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/MCQ-Questions/Tangent_Plane_Approximations_mcq_questions.pdf b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/MCQ-Questions/Tangent_Plane_Approximations_mcq_questions.pdf
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diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The_Second_Derivative_Test_MCQ.pdf b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/MCQ-Questions/The_Second_Derivative_Test_mcq_questions.pdf
index ca60cbf..ca60cbf 100644
--- a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The_Second_Derivative_Test_MCQ.pdf
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/MCQ-Questions/The_Second_Derivative_Test_mcq_questions.pdf
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diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/MCQ-Questions/Total_Differential_mcq_questions.pdf b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/MCQ-Questions/Total_Differential_mcq_questions.pdf
new file mode 100644
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diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/README.md b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/README.md
new file mode 100644
index 0000000..2a274d0
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/README.md
@@ -0,0 +1,26 @@
+<h1><div align=”center”><b>SubTopic: Tangent Plane Approximations</b></h1></div>
+<br/></br>
+
+<tab>file1_Tangent_Plane
+
+![file1_Tangent_Plane](https://github.com/vnb09/FSF-mathematics-python-code-archive/blob/fsf_tasks/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/file1_Tangent_Plane.gif?raw=true)
+<br/></br>
+<br/></br>
+
+<tab>file2_Tangent_plane_approximation_visualization
+
+![file2_Tangent_plane_approximation_visualization](https://github.com/vnb09/FSF-mathematics-python-code-archive/blob/fsf_tasks/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/file2_Tangent_plane_approximation_visualization.gif?raw=true)
+<br/></br>
+<br/></br>
+
+<tab>file3_Non_Differentiable_Function
+
+![file3_Non_Differentiable_Function](https://github.com/vnb09/FSF-mathematics-python-code-archive/blob/fsf_tasks/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/file3_Non_Differentiable_Function.gif?raw=true)
+<br/></br>
+<br/></br>
+
+<tab>file4_Tangent_plane_at_extrema_and_saddle_point
+
+![file4_Tangent_plane_at_extrema_and_saddle_point](https://github.com/vnb09/FSF-mathematics-python-code-archive/blob/fsf_tasks/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/file4_Tangent_plane_at_extrema_and_saddle_point.gif?raw=true)
+<br/></br>
+<br/></br>
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/file1_Tangent_Plane.gif b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/file1_Tangent_Plane.gif
new file mode 100644
index 0000000..2b8bf5f
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/file1_Tangent_Plane.gif
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diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/file1_Tangent_Plane.py b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/file1_Tangent_Plane.py
new file mode 100644
index 0000000..8efdbd2
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/file1_Tangent_Plane.py
@@ -0,0 +1,50 @@
+from manimlib.imports import*
+
+#---- tangent plane is parallel to the surface of the funtion at a point
+class tangentplane(ThreeDScene):
+ def construct(self):
+
+ s1_text=TextMobject("Suppose, the point $(x,y)$ lies on the surface of the function.").scale(0.5).shift(2*UP)
+ s2_text=TextMobject("When zooming on that point, the surface would appear more and more like a plane.").scale(0.5).shift(1*UP)
+ s3_text=TextMobject("This plane is called the tangent plane.").scale(0.5)
+
+ #---- graph of function f(x,y) = -x^2-y^2
+
+ f = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ -u**2-v**2
+ ]),v_min = -1, v_max = 1, u_min = -1, u_max = 1, checkerboard_colors = [YELLOW_B,YELLOW_C,YELLOW_D, YELLOW_E]).shift([0,0,0]).scale(1)
+
+
+ d = Dot([0,0,0],color = '#800000') #---- critical point
+
+ r = Rectangle(color = PURPLE,fill_opacity=0.2).shift([0.1,0,0]).scale(0.3) #---- tangent plane
+
+ s = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ -u**2-v**2
+ ]),v_min = -1, v_max = 1, u_min = -1, u_max = 1, checkerboard_colors = [YELLOW_B,YELLOW_C,YELLOW_D, YELLOW_E]).shift([0,0,0]).scale(3.5)
+
+ d2 = Dot([0,0,2.5],color = '#800000') #---- changing position of critical point
+
+ r2 = Rectangle(color = PURPLE,fill_opacity=0.5).shift([0.1,0,2.5]).scale(0.3) #---- changing position of tangent plane
+
+ self.set_camera_orientation(phi = 50 * DEGREES, theta = 45 * DEGREES)
+ self.add_fixed_in_frame_mobjects(s1_text)
+ self.add_fixed_in_frame_mobjects(s2_text)
+ self.add_fixed_in_frame_mobjects(s3_text)
+ self.wait(2)
+ self.play(FadeOut(s1_text))
+ self.play(FadeOut(s2_text))
+ self.play(FadeOut(s3_text))
+ self.wait(1)
+ self.play(Write(f))
+ self.play(Write(d))
+ self.play(Write(r))
+ self.wait(2)
+ self.play(ReplacementTransform(f,s),ReplacementTransform(d,d2),ReplacementTransform(r,r2))
+ self.wait(2)
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/file2_Tangent_plane_approximation_visualization.gif b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/file2_Tangent_plane_approximation_visualization.gif
new file mode 100644
index 0000000..6d5a67a
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/file2_Tangent_plane_approximation_visualization.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/file2_Tangent_plane_approximation_visualization.py b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/file2_Tangent_plane_approximation_visualization.py
new file mode 100644
index 0000000..02576d9
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/file2_Tangent_plane_approximation_visualization.py
@@ -0,0 +1,85 @@
+from manimlib.imports import*
+import math as m
+
+#---- tangent plane approximation visualization
+class ApproximationScene(ThreeDScene):
+ def construct(self):
+
+ axes = ThreeDAxes().scale(1.2).fade(0.7)
+ label_x= TextMobject("$x$").shift([5.4,-0.5,0]).fade(0.7) #---- x axis
+ label_y= TextMobject("$y$").shift([-0.5,5.2,0]).rotate(-4.5).fade(0.7) #---- y axis
+
+ #---- graph of the function
+ s = ParametricSurface(
+ lambda u, v: np.array([
+ 1.5*np.cos(u)*np.cos(v),
+ 1.5*np.cos(u)*np.sin(v),
+ 1.5*np.sin(u)
+ ]),u_min=0,u_max=PI,v_min=PI,v_max=2*PI,checkerboard_colors=[BLUE_B,BLUE_C,BLUE_D,BLUE_E]).shift([0,1,2.4]).scale(1.3)
+
+ d1 = Dot([0.2,2.01,2.24],color = '#800000').rotate(1.1,LEFT) #---- point(x_0,y_0)
+ d1_copy = Dot([0.2,2.01,0],color = '#800000') #---- projection of point(x_0,y_0) on x-y plane
+
+ d1_text = TextMobject("$f(x_0,y_0)$",color=ORANGE).scale(0.5).shift([0.2,2.01,2.3])
+ d1_copy_text = TextMobject("$(x_0,y_0)$",color=ORANGE).scale(0.5).shift([0.2,2.01,0],4.1*DOWN)
+
+ d2 = Dot([2,2.6,3.5],color = '#800000').rotate(1,LEFT) #---- point(x,y)
+ d2_copy = Dot([2,2.6,0],color = '#800000') #---- projection of point(x,y) on x-y plane
+
+ d2_text = TextMobject("$f(x,y)$",color=ORANGE).scale(0.5).shift([0.8,1.4,1.5])
+ d2_copy_text = TextMobject("$(x,y)$",color=ORANGE).scale(0.5).shift([0.8,1.4,0],2.4*DOWN)
+
+ l1 = Line([0.2,2.01,2.21],[0.2,2.01,0],color= YELLOW).fade(0.2)
+ l2 = Line([2,2.6,3.4],[2,2.6,0],color= YELLOW).fade(0.2)
+
+ t_plane = Rectangle(color = PURPLE, fill_opacity=0.3).scale(0.6).rotate(m.radians(45),LEFT).shift([1.1,2.5,3.1]) #---- tangent plane
+ t_text= TextMobject("Tangent Plane",color = PINK).scale(0.5).shift(0.3*RIGHT+2.6*UP).rotate(math.radians(5),LEFT)
+
+ a1 = Line([0.2,2.01,0],[2,2.6,0],color ="#00FF7F")
+ a_x = Line([0.2,2.01,0],[2,2.01,0],color ="#9400D3")
+ a_y = Line([0.2,2.01,0],[0.2,2.6,0],color ="#8B4513")
+ a2 = Line([2,2.01,0],[2,2.6,0])
+ a3 = Line([0.2,2.6,0],[2,2.6,0])
+
+ ax_text = TextMobject("$f_x (x_0 , y_0 )(x – x_0 ) $").scale(0.5).shift(DOWN+0.8*LEFT).rotate(0.4)
+ ay_text = TextMobject("$ f_y (x_0 , y_0 )(y – y_0 ) $").scale(0.5).shift(0.8*DOWN+2.7*RIGHT).rotate(-0.6)
+ a1_text = TextMobject("$f_x (x_0 , y_0 )(x – x_0 ) + f_y (x_0 , y_0 )(y – y_0 )$ ").scale(0.4).rotate(0.7).shift(1.7*DOWN+0.6*RIGHT)
+
+ lines = VGroup(a1,a_y,a_x,a2,a3,d1_copy,d2_copy)
+
+
+ self.set_camera_orientation(phi = 60 * DEGREES, theta = 55 * DEGREES)
+ self.wait(1)
+ self.add(axes)
+ self.add(label_x)
+ self.add(label_y)
+ self.play(Write(s))
+ self.wait(1)
+ self.play(Write(d2))
+ self.add_fixed_in_frame_mobjects(d1_text)
+ self.wait(1)
+ self.play(Write(t_plane))
+ self.add_fixed_in_frame_mobjects(t_text)
+ self.wait(1)
+ self.play(Write(d1))
+ self.add_fixed_in_frame_mobjects(d2_text)
+ self.wait(1)
+ self.play(Write(l1),Write(d1_copy))
+ self.add_fixed_in_frame_mobjects(d2_copy_text)
+ self.wait(1)
+ self.play(Write(l2),Write(d2_copy))
+ self.add_fixed_in_frame_mobjects(d1_copy_text)
+ self.wait(2)
+ self.play(FadeOut(d1_text),FadeOut(d1_copy_text),FadeOut(d2_text),FadeOut(d2_copy_text),FadeOut(t_text))
+ self.wait(1)
+ self.play(Write(a1),Write(a_x),Write(a_y),Write(a2),Write(a3))
+ self.wait(1)
+ self.play(FadeOut(s),FadeOut(d1),FadeOut(d2),FadeOut(l1),FadeOut(l2),FadeOut(t_plane),FadeOut(label_x),FadeOut(label_y))
+ self.wait(1)
+ lines.scale(2)
+ axes.scale(1.5)
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(ax_text)
+ self.add_fixed_in_frame_mobjects(ay_text)
+ self.add_fixed_in_frame_mobjects(a1_text)
+ self.wait(1)
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/file3_Non_Differentiable_Function.gif b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/file3_Non_Differentiable_Function.gif
new file mode 100644
index 0000000..7581a33
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/file3_Non_Differentiable_Function.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/file3_Non_Differentiable_Function.py b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/file3_Non_Differentiable_Function.py
new file mode 100644
index 0000000..79d0948
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/file3_Non_Differentiable_Function.py
@@ -0,0 +1,47 @@
+from manimlib.imports import*
+import math
+
+#---- tangent plane does not exists for f(x,y): sqrt(x**2+y**2) at origin
+
+class TangenttoSurface(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes().rotate(2.3)
+ axes2 = ThreeDAxes().scale(2).rotate(2.3).shift([0,0,1.3])
+
+ #----f(x,y): sqrt(x**2+y**2)
+ p = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ -math.sqrt(u**2+v**2)
+ ]),v_min = -1,v_max = 1, u_min = -1, u_max = 1, checkerboard_colors = [RED_C,TEAL_D],
+ resolution = (20, 20)).scale(1)
+
+ #----size increased of f(x,y): sqrt(x**2+y**2)
+ p2 = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ -math.sqrt(u**2+v**2)
+ ]),v_min = -1,v_max = 1, u_min = -1, u_max = 1, checkerboard_colors = [RED_C,TEAL_D],
+ resolution = (20, 20)).scale(3).shift([0,0,0])
+
+ self.set_camera_orientation(phi = 75 * DEGREES,theta = 40*DEGREES)
+
+ d = Dot([0,0,0],color = '#800000') #---- critical point
+ d2 = Dot([0,0,1.5],color = '#800000').scale(2) #---- size increased of critical point
+
+ f_text = TextMobject("$f$ is not differentiable at origin,because the surface").scale(0.5).to_corner(UL)
+ f2_text = TextMobject("is not flat when zoomed in at the origin.").scale(0.5).to_corner(UL).shift(0.5*DOWN)
+
+ self.add(axes)
+ self.wait(1)
+ self.play(Write(p),Write(d))
+ self.wait(1)
+ self.move_camera(phi = 50 * DEGREES,theta = 40*DEGREES)
+ self.wait(1)
+ self.play(ReplacementTransform(axes,axes2),ReplacementTransform(p,p2),ReplacementTransform(d,d2))
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(f_text)
+ self.add_fixed_in_frame_mobjects(f2_text)
+ self.wait(2)
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/file4_Tangent_plane_at_extrema_and_saddle_point.gif b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/file4_Tangent_plane_at_extrema_and_saddle_point.gif
new file mode 100644
index 0000000..3fe7992
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/file4_Tangent_plane_at_extrema_and_saddle_point.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/file4_Tangent_plane_at_extrema_and_saddle_point.py b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/file4_Tangent_plane_at_extrema_and_saddle_point.py
new file mode 100644
index 0000000..d129213
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Tangent-Plane-Approximations/file4_Tangent_plane_at_extrema_and_saddle_point.py
@@ -0,0 +1,62 @@
+from manimlib.imports import*
+
+class TangenttoSurface(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes()
+
+ #----graph of first function f(x,y) = -x**2-y**2
+ f = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ -u**2-v**2
+ ]),v_min = -1, v_max = 1, u_min = -1, u_max = 1, checkerboard_colors = [YELLOW_D, YELLOW_E],
+ resolution = (20, 20)).scale(1)
+ f_text = TextMobject("Tangent plane at relative maxima").to_corner(UL).scale(0.5)
+
+ #----graph of second function f(x,y) = -x**2+y**2
+ f2 = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ -u**2+v**2
+ ]),v_min = -1, v_max = 1, u_min = -1, u_max = 1, checkerboard_colors = [RED_D, RED_E],
+ resolution = (20, 20)).scale(1)
+ f2_text = TextMobject("Tangent plane at saddle point").to_corner(UL).scale(0.5)
+
+ #----graph of third function f(x,y) = x**2+y**2
+ f3 = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ u**2+v**2
+ ]),v_min = -1, v_max = 1, u_min = -1, u_max = 1, checkerboard_colors = [GREEN_D, GREEN_E],
+ resolution = (20, 20)).scale(1)
+ f3_text = TextMobject("Tangent plane at relative minima").to_corner(UL).scale(0.5)
+
+ self.set_camera_orientation(phi = 75 * DEGREES, theta = -45 * DEGREES )
+ d = Dot(np.array([0,0,0]), color = '#800000') #---- critical point
+
+ r = Rectangle(height = 2,breadth = 1,color = PURPLE).scale(0.5)
+
+ self.begin_ambient_camera_rotation(rate = 0.3)
+ self.add(axes)
+ self.play(Write(f),Write(d))
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(f_text)
+ self.play(ShowCreation(r))
+ self.wait(1)
+ self.play(FadeOut(r),FadeOut(f),FadeOut(d),FadeOut(f_text))
+ self.wait(1)
+ self.play(Write(f2),Write(d))
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(f2_text)
+ self.play(ShowCreation(r))
+ self.wait(1)
+ self.play(FadeOut(r),FadeOut(f2),FadeOut(d),FadeOut(f2_text))
+ self.wait(1)
+ self.play(Write(f3),Write(d))
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(f3_text)
+ self.play(ShowCreation(r))
+ self.wait(1)
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/README.md b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/README.md
new file mode 100644
index 0000000..96b32bf
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/README.md
@@ -0,0 +1,27 @@
+<h1><div align=”center”><b>SubTopic: The Second Derivative Test</b></h1></div>
+<br/></br>
+
+<tab>file1_Second_order_partial_derivatives
+
+![file1_Second_order_partial_derivatives](https://github.com/vnb09/FSF-mathematics-python-code-archive/blob/fsf_tasks/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/file1_Second_order_partial_derivatives.gif?raw=true)
+<br/></br>
+<br/></br>
+
+<tab>file2_Nondegenerate_Hessian_Matrix
+
+![file2_Nondegenerate_Hessian_Matrix](https://github.com/vnb09/FSF-mathematics-python-code-archive/blob/fsf_tasks/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/file2_Nondegenerate_Hessian_Matrix.gif?raw=true)
+<br/></br>
+<br/></br>
+
+<tab>file3_Degenerate_Hessian_Matrix
+
+![file3_Degenerate_Hessian_Matrix](https://github.com/vnb09/FSF-mathematics-python-code-archive/blob/fsf_tasks/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/file3_Degenerate_Hessian_Matrix.gif?raw=true)
+<br/></br>
+<br/></br>
+
+<tab>file4_Contour_Diagram
+
+![file4_Contour_Diagram](https://github.com/vnb09/FSF-mathematics-python-code-archive/blob/fsf_tasks/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/file4_Contour_Diagram.gif?raw=true)
+<br/></br>
+<br/></br>
+
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/file1_Second_order_partial_derivatives.gif b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/file1_Second_order_partial_derivatives.gif
new file mode 100644
index 0000000..3471e4d
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/file1_Second_order_partial_derivatives.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/file1_Second_order_partial_derivatives.py b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/file1_Second_order_partial_derivatives.py
new file mode 100644
index 0000000..84052cc
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/file1_Second_order_partial_derivatives.py
@@ -0,0 +1,78 @@
+from manimlib.imports import*
+
+#---- graphs of second-order partial derivatives of a function
+class SurfacesAnimation(ThreeDScene):
+ def construct(self):
+
+ axes = ThreeDAxes()
+ x_label = TextMobject('$x$').shift([5,0.5,0]) #---- x axis
+ y_label = TextMobject('$y$').shift([0.5,4,0]).rotate(-4.5) #---- y axis
+
+ #---- surface of function: f(x,y) = (x^2+y^2)^2
+ surface_f = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ ((u**2)+(v**2))**2
+ ]),v_min=-1,v_max=1,u_min=-1,u_max=1,checkerboard_colors=[GREEN_D, GREEN_E]).scale(1)
+
+ #---- surface of second-order partial derivative f_xx
+ surface_fxx = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ (3*u**2)+(v**2)
+ ]),v_min=-1,v_max=1,u_min=-1,u_max=1,checkerboard_colors=[YELLOW_D, YELLOW_E]).shift([0,0,0]).scale(0.6)
+
+ #---- surface of second-order partial derivative f_yy
+ surface_fyy = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ (u**2)+(3*v**2)
+ ]),v_min=-1,v_max=1,u_min=-1,u_max=1,checkerboard_colors=[PURPLE_D, PURPLE_E]).scale(0.6).shift([0,0,0])
+
+ #---- surface of second-order partial derivative f_xy = f_yx
+ surface_fxy = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ 8*u*v
+ ]),v_min=-1,v_max=1,u_min=-1,u_max=1,checkerboard_colors=[TEAL_D, TEAL_E]).scale(0.6)
+
+ f_text= TextMobject("$f(x,y) = (x^2+y^2)^2$",color = GREEN).scale(0.7).to_corner(UL)
+
+ fxx_text= TextMobject("$f_{xx} = 12x^2+4y^2$ (Concavity along x axis)",color = YELLOW).scale(0.5).to_corner(UL)
+
+ fyy_text= TextMobject("$f_{yy} = 4x^2+12y^2$(Concavity along y axis)",color = PURPLE).scale(0.5).to_corner(UL)
+
+ fxy_text= TextMobject("$f_{xy} = f_{yx} = 8xy$ (Twisting of the function)",color = TEAL).scale(0.5).to_corner(UL)
+
+
+ self.set_camera_orientation(phi = 40 * DEGREES, theta = 45 * DEGREES)
+ self.begin_ambient_camera_rotation(rate = 0.1)
+ self.add_fixed_in_frame_mobjects(f_text)
+ self.add(axes)
+ self.add(x_label)
+ self.add(y_label)
+ self.wait(1)
+ self.play(Write(surface_f))
+ self.wait(2)
+ self.play(FadeOut(f_text))
+
+
+ self.play(ReplacementTransform(surface_f,surface_fxx))
+
+ self.add_fixed_in_frame_mobjects(fxx_text)
+ self.wait(2)
+ self.play(FadeOut(fxx_text))
+
+ self.play(ReplacementTransform(surface_fxx,surface_fyy))
+ self.add_fixed_in_frame_mobjects(fyy_text)
+ self.wait(2)
+ self.play(FadeOut(fyy_text))
+
+ self.play(ReplacementTransform(surface_fyy,surface_fxy))
+ self.move_camera(phi = 35 * DEGREES, theta = 80 * DEGREES)
+ self.add_fixed_in_frame_mobjects(fxy_text)
+ self.wait(2)
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/file2_Nondegenerate_Hessian_Matrix.gif b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/file2_Nondegenerate_Hessian_Matrix.gif
new file mode 100644
index 0000000..0d58b4f
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/file2_Nondegenerate_Hessian_Matrix.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/file2_Nondegenerate_Hessian_Matrix.py b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/file2_Nondegenerate_Hessian_Matrix.py
new file mode 100644
index 0000000..32c1559
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/file2_Nondegenerate_Hessian_Matrix.py
@@ -0,0 +1,158 @@
+from manimlib.imports import*
+import math as m
+
+class Minima(ThreeDScene):
+ def construct(self):
+
+ heading = TextMobject("Nondegenerate Hessian Matrix",color = BLUE)
+
+ axes = ThreeDAxes()
+ label_x = TextMobject("$x$").shift([5.5,-0.3,0]) #---- x axis
+ label_y = TextMobject("$y$").shift([-0.3,5.5,0]).rotate(-4.5) #---- y axis
+
+ h_text = TextMobject("Case 1: $\\frac{\\partial^2 f}{\\partial x^2}>0$ and $\\frac{\\partial^2 f}{\\partial y^2}>0$").scale(1)
+
+ #---- determiniant of Hessian Matrix
+ hessian_surface = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ -0.5*m.exp(-u**2-v**2)
+ ]),u_min = -PI, u_max = PI, v_min = -PI, v_max =PI).set_color(TEAL).shift([0,0,0]).scale(1).fade(0.2)
+
+ det_text= TextMobject("$det \\hspace{1mm} H = (\\frac{\\partial^2 f}{\\partial x^2})(\\frac{\\partial^2 f}{\\partial y^2})-(\\frac{\\partial^2 f}{\\partial x \\partial y})^2 $").to_corner(UL).scale(0.7)
+
+ #---- function f(x,y)
+ f_surface = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ u**2+v**2
+ ]),u_min = -1.3, u_max = 1.3, v_min = -1.3, v_max = 1.3).set_color(TEAL).shift([0,0,-0.5])
+
+ f_text= TextMobject("surface of the function").to_corner(UL).scale(0.8)
+
+ d = Dot(color = "#800000").shift([0,0,-0.52]) #---- critical point
+
+ self.set_camera_orientation(phi = 75*DEGREES, theta = 40*DEGREES)
+ self.add_fixed_in_frame_mobjects(heading)
+ self.wait(1)
+ self.play(FadeOut(heading))
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(h_text)
+ self.wait(1)
+ self.play(FadeOut(h_text))
+ self.wait(1)
+ self.add(axes)
+ self.add(label_x)
+ self.add(label_y)
+ self.play(Write(hessian_surface))
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(det_text)
+ self.move_camera(phi = 90*DEGREES, theta= 60*DEGREES)
+ self.play(Write(d))
+ self.wait(1)
+ self.play(FadeOut(det_text),ReplacementTransform(hessian_surface,f_surface))
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(f_text)
+ self.wait(1)
+ self.play(FadeOut(f_text),FadeOut(f_surface),FadeOut(axes),FadeOut(label_x),FadeOut(label_y),FadeOut(d))
+
+class Maxima(ThreeDScene):
+ def construct(self):
+
+ axes = ThreeDAxes()
+ label_x = TextMobject("$x$").shift([5.5,-0.3,0]) #---- x axis
+ label_y = TextMobject("$y$").shift([-0.3,5.5,0]).rotate(-4.5) #---- y axis
+
+ h_text = TextMobject("Case 2: $\\frac{\\partial^2 f}{\\partial x^2}<0$ and $\\frac{\\partial^2 f}{\\partial y^2}<0$").scale(1)
+
+ #---- determiniant of Hessian Matrix
+ hessian_surface = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ 0.5*m.exp(-u**2-v**2)
+ ]),u_min = -PI, u_max = PI, v_min = -PI, v_max =PI).set_color(TEAL).shift([0,0,0]).scale(1).fade(0.2)
+
+ det_text= TextMobject("$det \\hspace{1mm} H = (\\frac{\\partial^2 f}{\\partial x^2})(\\frac{\\partial^2 f}{\\partial y^2})-(\\frac{\\partial^2 f}{\\partial x \\partial y})^2 $").to_corner(UL).scale(0.7)
+
+ #---- function g(x,y)
+ g_surface = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ -u**2-v**2
+ ]),u_min = -1.3, u_max = 1.3, v_min = -1.3, v_max = 1.3).set_color(TEAL).shift([0,0,0.5])
+
+ g_text= TextMobject("surface of the function").to_corner(UL).scale(0.8)
+
+ d = Dot(color = "#800000").shift([0,0,0.5]) #---- critical point
+
+ self.set_camera_orientation(phi = 75*DEGREES, theta = 40*DEGREES)
+ self.add_fixed_in_frame_mobjects(h_text)
+ self.wait(1)
+ self.play(FadeOut(h_text))
+ self.wait(1)
+ self.add(axes)
+ self.add(label_x)
+ self.add(label_y)
+ self.play(Write(hessian_surface))
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(det_text)
+ self.play(Write(d))
+ self.wait(1)
+ self.play(FadeOut(det_text),ReplacementTransform(hessian_surface,g_surface))
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(g_text)
+ self.wait(1)
+ self.play(FadeOut(g_text),FadeOut(g_surface),FadeOut(axes),FadeOut(label_x),FadeOut(label_y),FadeOut(d))
+
+class SaddlePoint(ThreeDScene):
+ def construct(self):
+
+ axes = ThreeDAxes()
+ label_x = TextMobject("$x$").shift([5.5,-0.3,0]) #---- x axis
+ label_y = TextMobject("$y$").shift([-0.3,5.5,0]).rotate(-4.5) #---- y axis
+
+ h_text = TextMobject("Case 3: $\\frac{\\partial^2 f}{\\partial x^2}$ and $\\frac{\\partial^2 f}{\\partial y^2}$ have opposite signs").scale(1)
+
+ #---- determiniant of Hessian Matrix
+ hessian_surface = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ m.exp(0.5*u**2-0.5*v**2)
+ ]),u_min = -1.2, u_max = 1.2, v_min = -2.5, v_max = 2.5).set_color(TEAL).shift([0,0,-1]).scale(1).fade(0.2)
+
+ det_text= TextMobject("$det \\hspace{1mm} H = (\\frac{\\partial^2 f}{\\partial x^2})(\\frac{\\partial^2 f}{\\partial y^2})-(\\frac{\\partial^2 f}{\\partial x \\partial y})^2 $").to_corner(UL).scale(0.7)
+
+ #---- function p(x,y)
+ p_surface = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ u**2-v**2
+ ]),u_min = -1, u_max = 1, v_min = -1, v_max =1).set_color(TEAL).shift([0,0,0]).scale(2)
+
+ p_text= TextMobject("surface of the function").to_corner(UL).scale(0.8)
+
+ d = Dot(color = "#800000").shift([0,0,0]) #---- critical point
+
+ self.set_camera_orientation(phi = 80*DEGREES, theta = 60*DEGREES)
+ self.add_fixed_in_frame_mobjects(h_text)
+ self.wait(1)
+ self.play(FadeOut(h_text))
+ self.wait(1)
+ self.add(axes)
+ self.add(label_x)
+ self.add(label_y)
+ self.wait(1)
+ self.play(Write(hessian_surface))
+ self.play(Write(d))
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(det_text)
+ self.wait(2)
+ self.play(FadeOut(det_text),ReplacementTransform(hessian_surface,p_surface))
+ self.add_fixed_in_frame_mobjects(p_text)
+ self.wait(2)
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/file3_Degenerate_Hessian_Matrix.gif b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/file3_Degenerate_Hessian_Matrix.gif
new file mode 100644
index 0000000..5aae300
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/file3_Degenerate_Hessian_Matrix.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/file3_Degenerate_Hessian_Matrix.py b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/file3_Degenerate_Hessian_Matrix.py
new file mode 100644
index 0000000..9310553
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/file3_Degenerate_Hessian_Matrix.py
@@ -0,0 +1,45 @@
+from manimlib.imports import*
+import math as m
+
+class DegenerateHessian(ThreeDScene):
+ def construct(self):
+
+ heading = TextMobject("Degenerate Hessian Matrix",color = BLUE)
+
+ h_text = TextMobject("For $det \\hspace{1mm} H = 0$, the surface of the function at the critical point would be flat.").scale(0.7)
+
+ axes = ThreeDAxes()
+ label_x = TextMobject("$x$").shift([5.5,-0.3,0]) #---- x axis
+ label_y = TextMobject("$y$").shift([-0.3,5.5,0]).rotate(-4.5) #---- y axis
+
+ #---- function f(x,y)
+ f_surface = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ -u**4-v**4
+ ]),u_min = -0.8, u_max = 0.8, v_min = -0.8, v_max = 0.8).set_color(TEAL).shift([0,0,-0.5]).scale(2)
+
+ f_text= TextMobject("surface of the function").to_corner(UL).scale(0.5)
+
+ d = Dot(color = "#800000").shift([0,0,-0.5]) #---- critical point
+ plane = Square(color = YELLOW,fill_opacity= 0.2).shift([0,0,-0.5]).scale(1.3)
+
+ self.set_camera_orientation(phi = 70*DEGREES, theta = 45*DEGREES)
+ self.add_fixed_in_frame_mobjects(heading)
+ self.wait(1)
+ self.play(FadeOut(heading))
+ self.add_fixed_in_frame_mobjects(h_text)
+ self.wait(2)
+ self.play(FadeOut(h_text))
+ self.wait(1)
+ self.add(axes)
+ self.add(label_x)
+ self.add(label_y)
+ self.play(Write(f_surface))
+ self.add_fixed_in_frame_mobjects(f_text)
+ self.wait(1)
+ self.play(Write(d))
+ self.wait(1)
+ self.play(Write(plane))
+ self.wait(1)
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/file4_Contour_Diagram.gif b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/file4_Contour_Diagram.gif
new file mode 100644
index 0000000..41068e2
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/file4_Contour_Diagram.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/file4_Contour_Diagram.py b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/file4_Contour_Diagram.py
new file mode 100644
index 0000000..d3084e2
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/The-Second-Derivative-Test/file4_Contour_Diagram.py
@@ -0,0 +1,120 @@
+from manimlib.imports import*
+
+#---- contour diagram animation
+class ContourDiagram(ThreeDScene):
+ def construct(self):
+
+ heading = TextMobject("CONTOUR DIAGRAM", color = YELLOW).scale(1)
+
+ axes = ThreeDAxes()
+ label_x = TextMobject("$x$").shift([5.5,-0.5,0]) #---- x axis
+ label_y = TextMobject("$y$").shift([-0.5,5.5,0]).rotate(-4.5) #---- y axis
+
+ #---- surface of a paraboloid
+ surface = ParametricSurface(
+ lambda u, v: np.array([
+ np.cos(v)*u,
+ np.sin(v)*u,
+ u**2
+ ]),v_min = -2, v_max = 2, u_min = -2, u_max = 2, checkerboard_colors = [GREEN_B,GREEN_C,GREEN_D,GREEN_E]).shift([0,0,0]).scale(0.5)
+
+ #---- first contour projection
+ contour1 = ParametricSurface(
+ lambda u, v: np.array([
+ np.cos(TAU * v),
+ np.sin(TAU * v),
+ 2*(1 - 2.5*u)
+ ])).fade(0.5).scale(0.21).shift([0,0,1.01])
+
+ #---- first contour line
+ c_1 = Circle(color = BLUE).scale(0.21).shift([0,0,0]).rotate(0.1,DOWN)
+
+ #-------------------------------------------------
+
+ #---- second contour projection
+ contour2 = ParametricSurface(
+ lambda u, v: np.array([
+ np.cos(TAU * v),
+ np.sin(TAU * v),
+ 2*(1 - 1.6*u)
+ ])).fade(0.5).scale(0.41).shift([0,0,0.3]).set_color(RED)
+
+ #---- second contour line
+ c_2 = Circle(color = RED).scale(0.41).shift([0,0,0]).rotate(0.1,DOWN)
+
+ #-------------------------------------------------
+
+ #---- third contour projection
+ contour3 = ParametricSurface(
+ lambda u, v: np.array([
+ np.cos(TAU * v),
+ np.sin(TAU * v),
+ 2*(1 - 1.5*u)
+ ])).fade(0.5).scale(0.61).shift([0,0,0.4]).set_color(YELLOW)
+
+ #---- third contour line
+ c_3 = Circle(color = YELLOW).scale(0.61).shift([0,0,0])
+
+ #-------------------------------------------------
+
+ #---- fourth contour projection
+ contour4 = ParametricSurface(
+ lambda u, v: np.array([
+ np.cos(TAU * v),
+ np.sin(TAU * v),
+ 2*(1 - 1.5*u)
+ ])).fade(0.7).scale(0.81).shift([0,0,0.7]).set_color(PINK)
+
+ #---- fourth contour line
+ c_4 = Circle(color = PINK).scale(0.81).shift([0,0,0])
+
+ #-------------------------------------------------
+
+ #---- fifth contour projection
+ contour5 = ParametricSurface(
+ lambda u, v: np.array([
+ np.cos(TAU * v),
+ np.sin(TAU * v),
+ 2*(1 - 1.5*u)
+ ])).fade(0.7).scale(1.01).shift([0,0,1]).set_color(PURPLE)
+
+ #---- fifth contour line
+ c_5 = Circle(color = PURPLE).scale(1.01).shift([0,0,0])
+
+ c_text= TextMobject("Contour Lines").scale(0.5).shift(2*DOWN)
+ s = Square().scale(1.3)
+
+ self.set_camera_orientation(phi = 75 * DEGREES, theta = 10 * DEGREES)
+ self.add_fixed_in_frame_mobjects(heading)
+ self.wait(1)
+ self.play(FadeOut(heading))
+ self.wait(1)
+ self.add(axes)
+ self.add(label_x)
+ self.add(label_y)
+ self.play(Write(surface))
+ self.wait(1)
+ self.add(contour1)
+ self.wait(1)
+ self.play(Write(c_1))
+ self.play(ReplacementTransform(contour1,contour2))
+ self.wait(1)
+ self.play(Write(c_2))
+ self.play(ReplacementTransform(contour2,contour3))
+ self.wait(1)
+ self.play(Write(c_3))
+ self.play(ReplacementTransform(contour3,contour4))
+ self.wait(1)
+ self.play(Write(c_4))
+ self.play(ReplacementTransform(contour4,contour5))
+ self.wait(1)
+ self.play(Write(c_5))
+ self.wait(1)
+ self.play(FadeOut(contour5),FadeOut(axes),FadeOut(label_x),FadeOut(label_y),FadeOut(surface),FadeOut(contour5),FadeOut(contour4),FadeOut(contour3),FadeOut(contour2),FadeOut(contour1))
+ self.wait(1)
+ self.move_camera(phi=0 * DEGREES,theta= 90*DEGREES)
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(c_text)
+ self.wait(1)
+ self.play(ShowCreation(s),FadeOut(c_text))
+ self.wait(1)
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/README.md b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/README.md
new file mode 100644
index 0000000..ce4da11
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/README.md
@@ -0,0 +1,34 @@
+<h1><div align=”center”><b>SubTopic: Total Differential</b></h1></div>
+<br/></br>
+
+<tab>file1_Visualization_of_dz
+
+![file1_Visualization_of_dz](https://github.com/vnb09/FSF-mathematics-python-code-archive/blob/fsf_tasks/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file1_Visualization_of_dz.gif?raw=true)
+<br/></br>
+<br/></br>
+
+<tab>file2_Differentials
+
+![file2_Differentials](https://github.com/vnb09/FSF-mathematics-python-code-archive/blob/fsf_tasks/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file2_Differentials.gif?raw=true)
+
+<br/></br>
+<br/></br>
+
+<tab>file3_Total_differential_of_z
+
+![file3_Total_differential_of_z](https://github.com/vnb09/FSF-mathematics-python-code-archive/blob/fsf_tasks/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file3_Total_differential_of_z.gif?raw=true)
+<br/></br>
+<br/></br>
+
+<tab>file4_total_differential_change
+
+![file4_total_differential_change](https://github.com/vnb09/FSF-mathematics-python-code-archive/blob/fsf_tasks/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file4_total_differential_change.gif?raw=true)
+<br/></br>
+<br/></br>
+
+<tab>file5_Total_differential_approximation
+
+ ![file5_Total_differential_approximation](https://github.com/vnb09/FSF-mathematics-python-code-archive/blob/fsf_tasks/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file5_Total_differential_approximation.gif?raw=true)
+
+<br/></br>
+<br/></br>
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file1_Visualization_of_dz.gif b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file1_Visualization_of_dz.gif
new file mode 100644
index 0000000..2e148af
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file1_Visualization_of_dz.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file1_Visualization_of_dz.py b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file1_Visualization_of_dz.py
new file mode 100644
index 0000000..1fdd0b9
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file1_Visualization_of_dz.py
@@ -0,0 +1,59 @@
+from manimlib.imports import*
+
+#---- visualization of total differential dz between two points lying on the surface of the function
+class differentialdz(ThreeDScene):
+
+ def construct(self):
+
+ axes = ThreeDAxes()
+ label_x = TextMobject("$x$").shift([5.5,-0.5,0]).fade(0.4) #---- x axis
+ label_y = TextMobject("$y$").shift([-0.5,5.5,0]).rotate(-4.5).fade(0.4) #---- y axis
+
+ #---- surface of the funtion f(x,y)
+ surface = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ u**2+v**2
+ ]),u_min=-1,u_max=1, v_min=-1,v_max=1).set_color("#FF69B4").fade(0.6).scale(2).shift(3*UP+1*LEFT)
+
+ d = Dot([1.4,1.75,1],color = '#00FFFF').rotate(1.571,UP) #---- point on the surface
+ d2 = Dot([2,2,1],color = '#00FFFF').rotate(1.571,UP) #---- point on the surface
+
+ p1 = TextMobject("$P_1$",color ='#ADFF2F').scale(0.6).shift(2*RIGHT+1*UP)
+ p2 = TextMobject("$P_2$",color = '#ADFF2F').scale(0.6).shift(2.6*RIGHT+0.9*UP)
+
+ l = DashedLine(color = '#800000').rotate(1.571,UP).scale(1).shift(1.7*UP+1.6*RIGHT)
+ l2 = DashedLine(color = '#800000').rotate(1.571,UP).scale(0.8).shift(2.26*UP+1.2*RIGHT)
+
+ l_text = TextMobject("$(x_1,y_1)$",color = '#ADFF2F').scale(0.6).shift(2*RIGHT+1.6*DOWN)
+ l2_text = TextMobject("$(x_2,y_2)$",color = '#ADFF2F').scale(0.6).shift(2.7*RIGHT+1.2*DOWN)
+
+ a = Arrow(color = '#FFFACD').scale(0.7).rotate(1.38,RIGHT).shift(2.5*LEFT+3.1*UP)
+
+ a_text = TextMobject("$dz$",color='#800000').scale(0.5).shift(2.3*RIGHT+0.5*UP)
+
+ plane = Rectangle(color = '#E6E6FA',fill_opacity = 1).scale(3).shift(1*RIGHT+3*UP).fade(0.9)
+
+ label = TextMobject("$z = f(x,y)$").scale(0.6).shift(3.5*RIGHT+1.8*UP)
+
+ self.set_camera_orientation(phi=75*DEGREES,theta=-10*DEGREES)
+ self.add(axes)
+ self.add(label_x)
+ self.add(label_y)
+ self.wait(1)
+ self.play(Write(plane))
+ self.play(Write(surface))
+ self.add_fixed_in_frame_mobjects(label)
+ self.wait(1)
+ self.play(ShowCreation(l),ShowCreation(l2),Write(d),Write(d2))
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(p1)
+ self.add_fixed_in_frame_mobjects(p2)
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(l_text)
+ self.add_fixed_in_frame_mobjects(l2_text)
+ self.play(ShowCreation(a))
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(a_text)
+ self.wait(2)
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file2_Differentials.gif b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file2_Differentials.gif
new file mode 100644
index 0000000..6baf271
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file2_Differentials.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file2_Differentials.py b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file2_Differentials.py
new file mode 100644
index 0000000..1025210
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file2_Differentials.py
@@ -0,0 +1,77 @@
+from manimlib.imports import*
+
+#---- visualization of the differentials along the axes
+class differentials(ThreeDScene):
+ def construct(self):
+
+ axes = ThreeDAxes()
+ label_x = TextMobject("$x$").shift([5.5,-0.3,0]).fade(0.4) #---- x axis
+ label_y = TextMobject("$y$").shift([-0.5,5.5,0]).rotate(-4.5).fade(0.4) #---- y axis
+
+ surface = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ u**2+v**2
+ ]),u_min=-1,u_max=1, v_min=-1,v_max=1).set_color("#FF69B4").shift([0,2.5,0.3]).scale(1.2) #----surface z = f(x,y)
+
+
+
+ plane = Rectangle(color = '#E6E6FA',fill_opacity = 1).scale(3).shift(-1*RIGHT+3*UP).fade(0.9)
+
+ d = Dot([1,2,1],color = '#9400D3').rotate(1.571,UP)
+ d2 = Dot([2,2.9,1],color = '#9400D3').rotate(1.571,UP)
+
+ p1 = TextMobject("$P_1$",color ='#ADFF2F').scale(0.6).shift(2*RIGHT+1*UP)
+ p2 = TextMobject("$P_2$",color = '#ADFF2F').scale(0.6).shift(2.6*RIGHT+0.4*UP)
+
+
+ l1 = DashedLine(color = '#00BFFF').scale(1.6).shift(3.5*UP+3.25*LEFT).rotate(1.571)
+ l2 = DashedLine(color = '#00BFFF').scale(1).shift(4*UP+2*LEFT).rotate(1.571)
+
+ label_dz= TextMobject("$dz$").scale(0.4).shift(5.3*RIGHT+0.4*UP)
+
+
+ l3 = Line(color = '#FFDAB9').scale(0.8).shift(1.95*UP+0.7*RIGHT).rotate(1.571,DOWN).fade(0.2)
+ l4 = Line(color = '#FFDAB9').scale(0.6).shift(2.86*UP+0.9*RIGHT).rotate(1.571,DOWN).fade(0.2)
+
+ line_y1 = DashedLine(color = '#00BFFF').scale(1.3).shift(0.82*UP+3.25*RIGHT).rotate(1.571)
+ line_y2 = DashedLine(color = '#00BFFF').scale(1.7).shift(1.2*UP+2.8*RIGHT).rotate(1.571)
+
+ label_dy= TextMobject("$dy$").scale(0.6).shift(3*RIGHT+0.8*DOWN).rotate(math.radians(90))
+
+ line_x1 = DashedLine(color = '#00BFFF').scale(1.5).shift(2.2*UP+1.6*RIGHT).rotate(1.571,RIGHT)
+ line_x2 = DashedLine(color = '#00BFFF').scale(1.2).shift(2.9*UP+1.6*RIGHT).rotate(1.571,RIGHT)
+
+ label_dx= TextMobject("$dx$").scale(0.4).shift(-0.4*UP+2.5*RIGHT)
+
+ label = TextMobject("$f(x,y)$").scale(0.6).shift(4*RIGHT+3*UP)
+
+
+ self.set_camera_orientation(phi=75*DEGREES,theta=10*DEGREES)
+ self.add(axes)
+ self.add(label_x)
+ self.add(label_y)
+ self.play(Write(plane))
+ self.play(Write(surface))
+ self.add_fixed_in_frame_mobjects(label)
+ self.wait(1)
+ self.play(Write(d),Write(d2))
+ self.add_fixed_in_frame_mobjects(p1)
+ self.add_fixed_in_frame_mobjects(p2)
+ self.wait(1)
+ self.play(Write(l1))
+ self.play(Write(l2))
+ self.add_fixed_in_frame_mobjects(label_dz)
+ self.wait(1)
+ self.play(Write(l3))
+ self.play(Write(l4))
+ self.wait(1)
+ self.play(Write(line_y1))
+ self.play(Write(line_y2))
+ self.play(ShowCreation(label_dy))
+ self.wait(1)
+ self.play(Write(line_x1))
+ self.play(Write(line_x2))
+ self.add_fixed_in_frame_mobjects(label_dx)
+ self.wait(1)
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file3_Total_differential_of_z.gif b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file3_Total_differential_of_z.gif
new file mode 100644
index 0000000..a54d2da
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file3_Total_differential_of_z.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file3_Total_differential_of_z.py b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file3_Total_differential_of_z.py
new file mode 100644
index 0000000..b8d6f96
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file3_Total_differential_of_z.py
@@ -0,0 +1,100 @@
+from manimlib.imports import*
+
+#---- visualization of total differential definition
+class totaldifferential(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes().fade(0.5)
+ surface = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ u**2+v**2
+ ]),u_min=-1,u_max=1, v_min=-1,v_max=1).set_color("#FF69B4").fade(0.6).shift([1,0.8,1.5]).scale(2)
+
+ plane = Rectangle(color = '#E6E6FA',fill_opacity = 1).scale(3).shift(-1*RIGHT+3*UP).fade(0.9)
+ label_x = TextMobject("$x$").shift(5*RIGHT+0.4*DOWN).rotate(1.571)
+ label_y = TextMobject("$y$").shift(0.3*DOWN+5.6*RIGHT).scale(0.5)
+ label_z = TextMobject("$z$").shift(3.5*UP+0.2*LEFT).scale(0.5)
+
+ s1 = Square(color = '#00FF00',fill_opacity=0.4).shift([1,1,0])
+ s2 = Square(color = '#00FF00',fill_opacity=0.4).shift([1,1,3]).scale(0.95)
+
+ l1 = Line([2,0,3],[2,0,0],color = '#FFFACD')
+ l2 = Line([0,2,3],[0,2,0],color = '#FFFACD')
+ l3 = Line([2,1.95,3],[2,2,0],color = '#FFFACD')
+
+ d1 = Dot([2,0,1.5],color = '#FFD700').rotate(1.571,UP)
+ d1_text = TextMobject("$P1$").scale(0.4).shift(1.2*LEFT+1.1*UP)
+
+ d2 = Dot([0,2,3],color = '#FFD700').rotate(1.571,UP)
+ d2_text = TextMobject("$P2$").scale(0.4).shift(2.3*RIGHT+3.1*UP)
+
+ d3 = Dot([2,2,2],color = '#FFD700').rotate(1.571,UP)
+ d3_text = TextMobject("$Q$").scale(0.4).shift([1.6,-1,0]+2.5*UP)
+
+ s3 = Square().shift([1,1,1.5]).scale(0.95)
+ s4 = Square().shift([1,1,2]).scale(0.95)
+
+ m1_line = DashedLine([2,0,1.5],[2,2,2],color = '#87CEEB')
+ m2_line = DashedLine([2,2,2],[0,2,3],color = '#87CEEB')
+
+ dx_line = Line([2,2,0],[4,2,0],color = '#00FF7F')
+ dy_line = Line([2,2,0],[2,4,0],color = '#00FF7F')
+
+ dx = DashedLine([3.5,0,0],[3.5,2,0],color = '#87CEEB')
+ dy = DashedLine([0,3.5,0],[2,3.5,0],color = '#87CEEB')
+
+ dx_text = TextMobject("$dx$").scale(0.8).shift([4,1,0]).rotate(1.571)
+ dy_text = TextMobject("$dy$").scale(0.8).shift([1,3.8,0]).rotate(math.radians(180))
+
+ parx_line = Line([0,2,1.5],[0,5,1.5],color = '#00FF7F')
+ parm_line = Line([0,2,2],[0,5,2],color = '#00FF7F')
+ pary_line = Line([0,2.1,3],[0,5,3],color = '#00FF7F')
+
+ delx = DashedLine([0,4,2],[0,4,1.5],color = '#F0F8FF')
+ dely = DashedLine([0,4,3],[0,4,2],color = '#FAEBD7')
+
+ dely_text = TextMobject("$\\frac{\\partial z}{\\partial y}dy$").shift(4.6*RIGHT+2.3*UP).scale(0.4)
+ delx_text = TextMobject("$\\frac{\\partial z}{\\partial x}dx$").shift(4.6*RIGHT+1.4*UP).scale(0.4)
+
+
+ self.set_camera_orientation(phi=75*DEGREES,theta=20*DEGREES)
+ self.add(axes)
+ self.play(Write(plane))
+ self.play(ShowCreation(label_x))
+ self.add_fixed_in_frame_mobjects(label_y)
+ self.add_fixed_in_frame_mobjects(label_z)
+ self.wait(1)
+ self.play(Write(surface))
+ self.play(ShowCreation(d1))
+ self.add_fixed_in_frame_mobjects(d1_text)
+ self.play(ShowCreation(d2))
+ self.add_fixed_in_frame_mobjects(d2_text)
+ self.wait(1)
+ self.play(Write(s2))
+ self.wait(1)
+ self.play(Write(l1),Write(l2),Write(l3))
+ self.wait(1)
+ self.play(Write(s1))
+ self.wait(1)
+ self.play(FadeOut(surface))
+ self.play(ShowCreation(d3))
+ self.add_fixed_in_frame_mobjects(d3_text)
+ self.play(ShowCreation(m1_line))
+ self.play(ShowCreation(m2_line))
+ self.wait(1)
+ self.play(ShowCreation(dx_line),ShowCreation(dx),ShowCreation(dx_text))
+ self.wait(1)
+ self.play(ShowCreation(dy_line),ShowCreation(dy),ShowCreation(dy_text))
+ self.wait(2)
+ self.play(Write(s3))
+ self.play(Write(s4))
+ self.wait(1)
+ self.play(ShowCreation(parx_line),ShowCreation(parm_line),ShowCreation(pary_line))
+ self.wait(1)
+ self.play(ShowCreation(dely))
+ self.add_fixed_in_frame_mobjects(dely_text)
+ self.wait(1)
+ self.play(ShowCreation(delx))
+ self.add_fixed_in_frame_mobjects(delx_text)
+ self.wait(1)
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file4_total_differential_change.gif b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file4_total_differential_change.gif
new file mode 100644
index 0000000..f2227a8
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file4_total_differential_change.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file4_total_differential_change.py b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file4_total_differential_change.py
new file mode 100644
index 0000000..78e41a2
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file4_total_differential_change.py
@@ -0,0 +1,54 @@
+from manimlib.imports import*
+
+
+class firstScene(ThreeDScene):
+
+ def construct(self):
+
+ axes = ThreeDAxes()
+
+ s = Rectangle(color = '#F08080',fill_opacity=1).fade(0.7).shift(1.9*UP+5*LEFT).scale(0.9)#----surface z = f(x,y)
+
+ s2= Rectangle(color = '#F08080',fill_opacity=1).fade(0.7).shift(2.4*UP+3.1*RIGHT).scale(0.6) #----reflection of the surface on the x-y plane
+
+ l1 = DashedLine(color = '#AFEEEE').rotate(1.571,UP).scale(1).shift(1.53*UP+1.5*RIGHT)
+ l2 = DashedLine(color = '#AFEEEE').rotate(1.571,UP).scale(1).shift(2.9*UP+1.4*RIGHT)
+ l3 = DashedLine(color = '#AFEEEE').rotate(1.571,UP).scale(1).shift(1.5*UP-1.6*RIGHT)
+ l4 = DashedLine(color = '#AFEEEE').rotate(1.571,UP).scale(1).shift(2.9*UP-1.75*RIGHT)
+
+
+ l1_text = TextMobject("$(x+\\triangle x,y)$").shift(RIGHT+1.7*DOWN).scale(0.4)
+ l2_text = TextMobject("$(x+\\triangle x,y+\\triangle y)$").shift(3*RIGHT+1.8*DOWN).scale(0.4)
+ l3_text = TextMobject("$f(x,y)$").shift(1.6*RIGHT+1.5*UP).scale(0.4)
+ l4_text = TextMobject("$(x,y+\\triangle y)$").shift(3.5*RIGHT+0.7*DOWN).scale(0.4)
+
+ label_x = TextMobject("$x$").shift(5*RIGHT+0.4*DOWN)
+ label_y = TextMobject("$y$").shift(5*UP-0.6*RIGHT)
+
+ self.add(axes)
+ self.set_camera_orientation(phi=75*DEGREES,theta=10*DEGREES)
+ self.wait(1)
+ self.play(ShowCreation(label_x),ShowCreation(label_y))
+ self.play(Write(s))
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(l3_text)
+ self.wait(1)
+ self.play(Write(l3))
+ self.wait(1)
+ self.play(Write(l1))
+ self.add_fixed_in_frame_mobjects(l1_text)
+ self.wait(1)
+ self.play(Write(l2))
+ self.add_fixed_in_frame_mobjects(l2_text)
+ self.wait(1)
+ self.play(Write(l4))
+ self.add_fixed_in_frame_mobjects(l4_text)
+ self.wait(1)
+ self.play(Write(s2))
+ self.wait(1)
+
+
+
+
+
+
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file5_Total_differential_approximation.gif b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file5_Total_differential_approximation.gif
new file mode 100644
index 0000000..ebbf240
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file5_Total_differential_approximation.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file5_Total_differential_approximation.py b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file5_Total_differential_approximation.py
new file mode 100644
index 0000000..e7b39bb
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/approximations-and-optimizations/Total-Differential/file5_Total_differential_approximation.py
@@ -0,0 +1,52 @@
+from manimlib.imports import*
+
+#---- approximation value of function between two points using total differentials
+class approximation(ThreeDScene):
+
+ def construct(self):
+
+ axes = ThreeDAxes()
+ label_x = TextMobject("$x$").shift([5.5,-0.3,0]).fade(0.4) #---- x axis
+ label_y = TextMobject("$y$").shift([-0.5,5.5,0]).rotate(-4.5).fade(0.4) #---- y axis
+
+ surface = ParametricSurface(
+ lambda u, v: np.array([
+ np.sin(u),
+ v,
+ -u**2-v
+ ]),u_min=-1,u_max=1, v_min=-1,v_max=1).set_color("#00008B").scale(2).shift(3.8*UP+2*LEFT)
+
+ d = Dot([1.4,1.75,1],color = '#00FFFF').rotate(1.571,UP)
+ d2 = Dot([2,2,1],color = '#00FFFF').rotate(1.571,UP)
+
+ l = DashedLine(color = '#800000').rotate(1.571,UP).scale(1).shift(1.7*UP+1.6*RIGHT)
+ l2 = DashedLine(color = '#800000').rotate(1.571,UP).scale(0.8).shift(2.26*UP+1.2*RIGHT)
+
+ l_text = TextMobject("$(x_1,y_1)$",color = '#ADFF2F').scale(0.6).shift(2*RIGHT+1.6*DOWN)
+ l2_text = TextMobject("$(x_2,y_2)$",color = '#ADFF2F').scale(0.6).shift(2.7*RIGHT+1.2*DOWN)
+
+ plane = Rectangle(color = '#E6E6FA',fill_opacity = 1).scale(3).shift(1*RIGHT+3*UP).fade(0.9)
+
+ tangentplane = Rectangle(color = '#E6E6FA',fill_opacity = 1).scale(1.1).shift(2*LEFT+3.4*UP).fade(0.5).rotate(0.8,RIGHT)
+ tangentplane_text = TextMobject("Tangent Plane").scale(0.4).shift(3*RIGHT+1*UP)
+
+ label = TextMobject("$z = f(x,y)$").scale(0.6).shift(4*RIGHT+3*UP)
+
+ self.set_camera_orientation(phi=75*DEGREES,theta=-10*DEGREES)
+ self.add(axes)
+ self.add(label_x)
+ self.add(label_y)
+ self.wait(1)
+ self.play(Write(plane))
+ self.wait(1)
+ self.play(Write(surface))
+ self.add_fixed_in_frame_mobjects(label)
+ self.wait(1.5)
+ self.play(ShowCreation(l),ShowCreation(l2),Write(d),Write(d2))
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(l_text)
+ self.add_fixed_in_frame_mobjects(l2_text)
+ self.wait(1)
+ self.play(Write(tangentplane))
+ self.add_fixed_in_frame_mobjects(tangentplane_text)
+ self.wait(2)
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/README.md b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/README.md
index e69de29..b46936b 100644
--- a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/README.md
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/README.md
@@ -0,0 +1,9 @@
+This repository contains the codes written by [Saarth Deshpande](https://github.com/saarthdeshpande) during the course of FOSSEE Summer Fellowship 2020 under the FLOSS: Mathematics using Python.
+
+__Sub-topics covered__:
+* Equations of Planes and Lines
+* General Parametric Curves
+* Space Curves (an Intro to Coordinates in 3D)
+* Velocity and Differentiability
+* Finding Arc Length and Curvature
+* TNB Frame and Serret-Frenet Formulae
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/README.md b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/README.md
new file mode 100644
index 0000000..10786d6
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/README.md
@@ -0,0 +1,11 @@
+**file1_simple_visualization.py** <br>
+![file1_simple_visualization.py](https://raw.githubusercontent.com/saarthdeshpande/FSF-mathematics-python-code-archive/master/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file1_simple_visualization.gif)
+
+**file2_circle_curvature.py** <br>
+![file2_circle_curvature.py](https://raw.githubusercontent.com/saarthdeshpande/FSF-mathematics-python-code-archive/master/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file2_circle_curvature.gif)
+
+**file3_curvature_interpretation.py** <br>
+![file3_curvature_interpretation.py](https://github.com/saarthdeshpande/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file3_curvature_interpretation.gif)
+
+**file4_different_curvature_single_curve.py** <br>
+![file4_different_curvature_single_curve.py](https://raw.githubusercontent.com/saarthdeshpande/FSF-mathematics-python-code-archive/master/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file4_different_curvature_single_curve.gif)
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file1_arc_length.gif b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file1_arc_length.gif
new file mode 100644
index 0000000..bbad112
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file1_arc_length.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file1_arc_length.py b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file1_arc_length.py
new file mode 100644
index 0000000..7c970e5
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file1_arc_length.py
@@ -0,0 +1,123 @@
+from manimlib.imports import *
+
+
+class arcl(MovingCameraScene):
+ def construct(self):
+ # self.setup()
+ def curve_(x):
+ return 3 - (3653*x**2)/5292 + (2477*x**3)/31752 + (13*x**4)/784 - (17*x**5)/5292 + (17*x**6)/63504
+
+ curve = FunctionGraph(curve_, x_min=-2, x_max=6, stroke_width = 2, color = BLUE).scale(0.1).move_to(ORIGIN)
+ lines = [Line(length = 0.05, color = RED).scale(0.2).move_to(ORIGIN).shift(np.array([-4 + 0.1*i, curve_(-2.5 + 0.1*i), 0])).rotate(-25*DEGREES) for i in range(4)]
+ lines2 = [Line(length = 0.05, color = RED).scale(0.2).move_to(ORIGIN).shift(np.array([-4 + 0.125*i, curve_(-2.5 + 0.1*i), 0])).rotate(-25*DEGREES) for i in range(4, 9)]
+ # lines[0].rotate(-25*DEGREES).shift(np.array([-4,curve_(-2.5), 0]))
+ # lines[1].rotate(-25*DEGREES).shift(np.array([-3.78,curve_(-2.3), 0]))
+ # lines3 = [Line(length = 0.05, color = RED).scale(0.2).move_to(ORIGIN + 1.5*UP + 0.6*RIGHT).shift(np.array([-1 + 0.2*i, -1.5 - 0.2*i, 0])).rotate(30*DEGREES) for i in range(4)]
+ # lines2b = VGroup(*lines3).rotate(-8*DEGREES)
+ # lines4 = [Line(length = 0.05, color = RED).scale(0.2).move_to(ORIGIN + 1.6*UP + 0.5*RIGHT).shift(np.array([-1 + 0.18*i, -1.65 - 0.2*i, 0])).rotate(22*DEGREES) for i in range(4, 9)]
+ # lines5 = [Line(length = 0.05, color = RED).scale(0.2).move_to(ORIGIN + 7*RIGHT).shift(np.array([-4 + 0.1*i, curve_(-2.5 + 0.1*i), 0])).rotate(-25*DEGREES) for i in range(4)]
+ # lines6 = [Line(length = 0.05, color = RED).scale(0.2).move_to(ORIGIN +7.25*RIGHT).shift(np.array([-4 + 0.053*i, curve_(-2.5 + 0.1*i), 0])).rotate(-26*DEGREES) for i in range(4, 9)]
+
+ # lc1 = [Line(length = 0.05, color = RED).scale(0.2).rotate((-25 + i*2) * DEGREES).shift(np.array([-1 + 0.125*i, curve_(-1.5 + 0.1*i), 0])) for i in range(2)]
+ # lc1b = VGroup(*lc1).shift(1.7*LEFT + 0.2*DOWN)
+
+ text = TextMobject(r'$r(t) = \left\langle t, t^{3} - 2t, 0\right\rangle$ \\ $r\prime (t) = \left\langle 1, 3t^{2} - 2, 0\right\rangle$').scale(0.7).shift(3*UP + 4*RIGHT)
+
+ # l = VGroup(*lines, *lines2, lines2b, *lines4, *lines5, *lines6, lc1b).shift(curve.get_center())
+ l = VGroup(*lines, *lines2)
+ arc = Line(lines[3].get_center(), lines2[0].get_center() + np.array([0.005, 0 ,0]), color = GREEN_SCREEN).rotate(12*DEGREES)
+ arctext = TextMobject(r'$ds$', color = GREEN_SCREEN).scale(0.15).next_to(arc.get_center(), 0.001*DOWN + 0.01*RIGHT,buff = 0.01)
+ dy = Arrow(arc.get_start(), np.array([arc.get_start()[0], lines2[0].get_center()[1] + 0.01, 0]), color = YELLOW)
+ dx = Arrow(arc.get_start(), np.array([lines2[0].get_center()[0] - 0.01, arc.get_start()[1], 0]), color = BLUE)
+ dxt = DashedLine(dy.get_end(), dy.get_end() + np.array([0.13, 0 ,0]))
+ dyt = DashedLine(dx.get_end(), dx.get_end() + np.array([0, 0.3 ,0]))
+ dxtext = TextMobject(r'$dx$').scale(0.2).next_to(dx, RIGHT, buff = 0.01)
+ dytext = TextMobject(r'$dy$').scale(0.2).next_to(dy, LEFT, buff = 0.01)
+ formula = TextMobject(r"Consider a very small interval ", r'$ds$. \\', r"Using Pythagoras' theorem, \\", r'$ds$', r" = $\sqrt{(dx)^{2} + (dy)^{2}}$").scale(0.25).shift(5*LEFT + 0.5*UP)
+ formula.set_color_by_tex_to_color_map({
+ "$ds$. \\": GREEN_SCREEN,
+ "$ds$": GREEN_SCREEN
+ })
+
+ formula2 = TextMobject(r'To compute the arc length \\ from $a$ to $b$, we need to \\ sum over all intervals ', r'$ds$').scale(0.25).shift(5.2*LEFT + 0.7*UP)
+ formula2.set_color_by_tex_to_color_map({
+ "$ds$": GREEN_SCREEN
+ })
+
+ formula3 = TextMobject(r'$L = \int_{a}^{b} ds$ \\ $= \int_{a}^{b} \sqrt{(\frac{dx}{dt})^{2} + (\frac{dy}{dt})^{2} + (\frac{dz}{dt})^{2}}\quad dt$').scale(0.25).shift(5.2*LEFT + 0.1*UP)
+
+ bl = DashedLine(lines2[4].get_center(), lines2[4].get_center() + np.array([1,0,0]))
+ blt = TextMobject(r'$b$').scale(0.5).next_to(bl.get_center(), DOWN, buff=0.1)
+ al = DashedLine(lines[0].get_center(), lines[0].get_center() + np.array([1,0,0]))
+ alt = TextMobject(r'$a$').scale(0.5).next_to(al.get_center(), UP, buff=0.1)
+ pts = VGroup(*[bl, blt, al, alt])
+
+ compute = TextMobject(r'To compute the arc length from \\ $t = -1.4$ to $t = -1.1$, \\ summation of small intervals $ds$ \\ is given by $L = \int_{-1.4}^{-1.1} ds$ \\').scale(0.7).shift(6.8*LEFT + 2.5*UP)
+ compute_ = TextMobject(r'L = $ \int_{-1.4}^{-1.1} \sqrt{(\frac{dx}{dt})^{2} + (\frac{dy}{dt})^{2} + (\frac{dz}{dt})^{2}}\quad dt$ \\ = $\int_{-1.4}^{-1.1} \sqrt{1^{2} + (3t^{2} - 2)^{2} + 0^{2}}\quad dt$').scale(0.7).shift(6.8*LEFT + -0.6*DOWN)
+ #compute = VGroup(*[compute, compute_])
+ compute2 = TextMobject(r'$ = \int_{-1.4}^{-1.1} \sqrt{9t^{4} - 12t^{2} + 5}\quad dt$').scale(0.7).shift(6.8*LEFT + 0.7*DOWN)
+ compute3 = TextMobject(r'$L = 0.8693$').scale(0.7).shift(6.8*LEFT + 1.2*DOWN)
+ arclen = compute3.copy()
+ arclen = arclen.scale(0.8).next_to(arc.get_center(), RIGHT, buff = 0.1)
+ dsd = TextMobject(r'We can divide the curve \\ into multiple small arcs ', r'$ds$').scale(0.25).shift(5.2*LEFT + 0.2*UP)
+ dsd.set_color_by_tex_to_color_map({
+ "$ds$": GREEN_SCREEN
+ })
+
+ # 13th sec, consider a v small interval ds, show Pythagoras
+ # reduce text size
+ # then show we can divide curve into small ds
+ # all red ds
+ # To compute arc length, we need to sum over all intervals ds
+ # a and b show and give dashes dy dx for first and last
+ # give dz in formula and show it's zero
+ # Zooom out, Remove red bars, draw yellow line
+ # Consider t = -1.4 to -1.1
+ # at end show l = 0.693 near yellow line, smaller size
+
+ ax1 = Vector((0,1,0), color = YELLOW)
+ ax1l = TextMobject(r'$y$').next_to(ax1, LEFT, buff = 0)
+ ax2 = Vector((1,0,0), color = BLUE)
+ ax2l = TextMobject(r'$x$').next_to(ax2, RIGHT, buff = 0)
+ ax = VGroup(*[ax1, ax1l, ax2, ax2l]).scale(0.6).shift(3*DOWN + 6*LEFT)
+
+ self.play(FadeIn(curve), FadeIn(ax))
+ self.play(ApplyMethod(curve.scale, 10), FadeIn(text))
+ # self.play(FadeIn(l))
+ self.wait(2)
+ self.play(FadeOut(text))
+ self.play(self.camera_frame.set_width, 5,
+ self.camera_frame.move_to, 3.8*LEFT+0.4*DOWN,
+ ax.shift, UP,
+ ax.scale, 0.5, run_time = 4)
+ long = ArcBetweenPoints(lines[1].get_center() + 0.01, lines2[3].get_center(), color = YELLOW, angle = 10*DEGREES).rotate(180*DEGREES)
+
+
+ self.play(Write(formula),FadeIn(VGroup(*[arc, arctext, dy, dx, dxt, dyt, dxtext, dytext])), FadeIn(VGroup(*[lines[3], lines2[0]])))
+ self.wait(2)
+ self.play(ReplacementTransform(formula, dsd), TransformFromCopy(VGroup(*[lines[3], lines2[0]]) , l))
+ #Transform(l, VGroup(*[lines[3], lines2[0]])), )
+ self.wait(2)
+ self.play(ReplacementTransform(dsd, formula2), FadeIn(pts))
+ self.wait(3)
+ self.play(FadeIn(formula3))
+ self.wait(2)
+ self.play(FadeOut(VGroup(*[formula3, l, pts, formula2, arc, arctext, dy, dx, dxt, dyt, dxtext, dytext])))
+ self.play(
+ self.camera_frame.set_width, 15,
+ self.camera_frame.move_to, 3*LEFT,
+ ax.shift, DOWN + 3*LEFT,
+ ax.scale, 2.3,
+ run_time = 4)
+ text = text.shift(2*LEFT)
+ self.play(FadeIn(long), FadeIn(compute), FadeIn(text))
+ self.wait(2)
+ self.play(FadeIn(compute_))
+ self.wait(2)
+ self.play(FadeIn(compute2))
+ self.wait(1)
+ self.play(FadeIn(compute3))
+ self.wait(1)
+ self.play(TransformFromCopy(compute3, arclen))
+ self.wait(2)
+ self.play(FadeOut(VGroup(*[ax, arclen, compute_, curve, text, compute, compute2, compute3, long])))
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file2_simple_visualization.gif b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file2_simple_visualization.gif
new file mode 100644
index 0000000..3f7ecd1
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file2_simple_visualization.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file2_simple_visualization.py b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file2_simple_visualization.py
new file mode 100644
index 0000000..05cad80
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file2_simple_visualization.py
@@ -0,0 +1,91 @@
+from manimlib.imports import *
+
+class a(GraphScene):
+ CONFIG = {
+ "x_min": -3,
+ "x_max": 6,
+ "y_min": -6,
+ "y_max": 10,
+ "graph_origin": ORIGIN
+ }
+ def construct(self):
+ intro = TextMobject('Consider the following curve.')
+ mid = TextMobject(r'Notice how the direction of the unit tangent vector\\changes with respect to the arc length.')
+ outro = TextMobject(r'The rate of change of unit tangent with \\ respect to the arc length $ds$ is called curvature.\\Mathematically, curvature $ = k = \left|{\frac{dT}{ds}}\right|$')
+
+ XTD = self.x_axis_width/(self.x_max- self.x_min)
+ YTD = self.y_axis_height/(self.y_max- self.y_min)
+
+ circle = Circle(radius = 0.95, color = GRAY, fill_opacity = 0.2, fill_color = RED)
+ circle.set_stroke(width = 0.1)
+
+ tgt1 = Arrow((-2.2*XTD,-0.5*YTD,0),(-1*XTD,1,0))
+ tgt2 = Arrow((-1.2*XTD, 1.93*YTD,0),(0*XTD,1.6,0)).scale(1.2)
+ tgt3 = Arrow((-0.3*XTD,3*YTD, 0), (1.5*XTD, 3*YTD,0))
+ tgt4 = Arrow((1.4*XTD, 2*YTD,0),(2.4*XTD, 1*YTD,0)).scale(2.8)
+ tgt5 = Arrow((2.4*XTD, 0, 0), (3.8*XTD,-2*YTD, 0)).scale(1.2).shift(0.26*RIGHT)
+ tgt6 = Arrow((3.8*XTD,-1*YTD, 0), (4.8*XTD, -1*YTD, 0)).scale(2.8).shift(0.26*RIGHT)
+ tgt7 = Arrow((5.3*XTD, 0, 0),(6.3*XTD,1,0)).shift(0.35*LEFT+0.1*DOWN).scale(1.3)
+
+ dot1 = Dot(tgt1.get_start(), color = RED)
+ dot2 = Dot(tgt2.get_start(), color = RED)
+ dot3 = Dot(tgt3.get_start(), color = RED)
+ dot4 = Dot(tgt4.get_start(), color = RED)
+ dot5 = Dot(tgt5.get_start(), color = RED)
+ dot6 = Dot(tgt6.get_start(), color = RED)
+ dot7 = Dot(tgt7.get_start(), color = RED)
+
+ arc = ArcBetweenPoints(dot1.get_center(), dot2.get_center(), color = GREEN_SCREEN, angle = 10*DEGREES).rotate(180*DEGREES)
+
+ dots = VGroup(*[dot1, dot2, dot3, dot4, dot5, dot6, dot7])
+
+ ds = CurvedArrow((-4, 2, 0), (tgt1.get_start() + tgt2.get_start()) / 2, color = YELLOW)
+ ds_text = TextMobject(r'$ds$').next_to(ds, UP, buff = 0.1).shift(1.3*LEFT)
+
+ self.setup_axes(hideaxes=True)
+
+ def curve(x):
+ return 3 - (3653*x**2)/5292 + (2477*x**3)/31752 + (13*x**4)/784 - (17*x**5)/5292 + (17*x**6)/63504
+
+ # parabola_x_out = FunctionGraph(curve, x_min=-2, x_max=6, stroke_width = 2, color = BLUE)
+ parabola_x_out = self.get_graph(curve)
+
+ dot_x = Dot().rotate(PI/2).set_color(YELLOW_E)
+ alpha_x = ValueTracker(-2)
+ vector_x = self.get_tangent_vector(alpha_x.get_value(),parabola_x_out,scale=1.5)
+ dot_x.add_updater(lambda m: m.move_to(vector_x.get_center()))
+ vector_x.add_updater(
+ lambda m: m.become(
+ self.get_tangent_vector(alpha_x.get_value()%1,parabola_x_out,scale=1.5)
+ )
+ )
+
+ self.play(FadeIn(intro))
+ self.wait(2)
+ self.play(FadeOut(intro))
+ self.setup_axes(hideaxes=False)
+ self.play(ShowCreation(parabola_x_out), FadeIn(dots), FadeIn(ds), FadeIn(ds_text), FadeIn(arc))
+ self.wait(2)
+ self.play(FadeOut(self.axes), FadeOut(arc), FadeOut(parabola_x_out),FadeIn(mid), FadeOut(dots), FadeOut(ds), FadeOut(ds_text))
+ self.wait(3)
+ self.play(FadeOut(mid))
+ self.play(FadeIn(self.axes), FadeIn(parabola_x_out), FadeIn(dots))
+ self.add(vector_x)
+ self.play(alpha_x.increment_value, 1, run_time=8, rate_func=linear)
+ self.remove(vector_x)
+ self.play(FadeOut(VGroup(*[self.axes, dots, parabola_x_out])))
+ self.play(FadeIn(outro))
+ self.wait(3)
+ self.play(FadeOut(outro))
+ self.wait(1)
+
+
+
+
+ def get_tangent_vector(self, proportion, curve, dx=0.001, scale=1):
+ coord_i = curve.point_from_proportion(proportion)
+ coord_f = curve.point_from_proportion(proportion + dx)
+ reference_line = Line(coord_i,coord_f)
+ unit_vector = reference_line.get_unit_vector() * scale
+ vector = Arrow(coord_i , coord_i + unit_vector, color = YELLOW, buff=0)
+ return vector
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file3_circle_curvature.gif b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file3_circle_curvature.gif
new file mode 100644
index 0000000..989a3b7
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file3_circle_curvature.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file3_circle_curvature.py b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file3_circle_curvature.py
new file mode 100644
index 0000000..232ac41
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file3_circle_curvature.py
@@ -0,0 +1,27 @@
+from manimlib.imports import *
+
+class circleC(GraphScene):
+ CONFIG = {
+ "x_min": -6,
+ "x_max": 6,
+ "y_min": -6,
+ "y_max": 6,
+ "graph_origin": ORIGIN,
+ "x_axis_width": 12,
+ "y_axis_height": 12
+ }
+ def construct(self):
+ epiphany = TextMobject(r'Driving a vehicle on which of \\ the two paths would be easier?').scale(0.6).shift(3.5*LEFT + 3*UP)
+ outro = TextMobject(r'The larger path, due to its \\ smaller curvature, since $k = \frac{1}{R}$.').scale(0.6).shift(3.7*LEFT + 3*UP)
+ XTD = self.x_axis_width/(self.x_max- self.x_min)
+ YTD = self.y_axis_height/(self.y_max- self.y_min)
+
+ circle = Circle(radius = 2, color = BLUE)
+ circle2 = Circle(radius = 3, color = GREEN_E)
+
+ self.setup_axes(hideaxes=True)
+ self.play(FadeIn(self.axes), Write(circle, run_time = 2), FadeIn(epiphany))
+ self.play(Write(circle2, run_time = 3))
+ self.play(ReplacementTransform(epiphany, outro))
+ self.wait(2)
+ self.play(FadeOut(VGroup(*[self.axes, circle, circle2, epiphany, outro])))
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file4_curvature_interpretation.gif b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file4_curvature_interpretation.gif
new file mode 100644
index 0000000..22a450a
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file4_curvature_interpretation.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file4_curvature_interpretation.py b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file4_curvature_interpretation.py
new file mode 100644
index 0000000..f10fa26
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file4_curvature_interpretation.py
@@ -0,0 +1,114 @@
+from manimlib.imports import *
+
+class interpretation(ZoomedScene):
+ CONFIG = {
+ "zoomed_display_height": 3,
+ "zoomed_display_width": 3,
+ "zoom_factor": 0.15,
+ "zoomed_display_center": ORIGIN + 4*LEFT + DOWN,
+ }
+ def construct(self):
+
+ tgt = Vector((1, 2, 0), color = YELLOW).shift(0.005*RIGHT + 0.007*DOWN)
+ dot = Dot(tgt.get_start(),color = RED)
+ curve = ParametricFunction(
+ lambda t: np.array([
+ 2*(t**2),
+ 4*t,
+ 0
+ ]), t_min = -5, t_max = 5
+ ).scale(0.3).move_to(ORIGIN + 4*RIGHT).rotate(6*DEGREES)
+
+ ds = ParametricFunction(
+ lambda t: np.array([
+ 2*(t**2),
+ 4*t,
+ 0
+ ]), t_min = 0, t_max = 0.05, color = GREEN_SCREEN
+ ).scale(0.9).shift(3.09*LEFT).rotate(-27.5*DEGREES).move_to(ORIGIN).shift(0.07*UP + 0.05*RIGHT).set_stroke(width=20)
+
+ dsl = TextMobject(r'$ds$', color = GREEN_SCREEN).scale(0.2).next_to(ds, RIGHT, buff = 0)
+
+
+ tgtText = TextMobject(r'$r\prime (t) = \left\langle 1, 2, 0\right\rangle$').next_to(tgt, UP, buff = 0).scale(0.7)
+ tgt2 = DashedLine((0,0,0),(1, 2, 0), color = GRAY).shift(DOWN + 2*RIGHT)
+ circle = Circle(radius = 0.9, color = GREEN_SCREEN).shift(0.85*RIGHT + 0.38*DOWN)
+ circle.set_stroke(opacity = 1)
+ dl = DashedLine(circle.get_center(), dot.get_center())
+ dltext = TextMobject(r'$R = 2.795$').scale(0.5).next_to(circle.get_center(), DOWN, buff = 0.1)
+
+ main = TextMobject(r'r(t) = $\left\langle t^{2}, 2t, 0 \right\rangle\quad r\prime (t) = \left\langle 2t, 2, 0 \right\rangle\quad$ \\ $r\prime\prime (t) = \left\langle 2, 0, 0 \right\rangle$').scale(0.7).shift(3*UP + 3*LEFT)
+ main2 = TextMobject(r'Curvature at an arbitrary point \\ say r(t = 0.5) can be given as: \\ $\kappa = \frac{1}{R} = \frac{1}{2.795} = 0.357$').scale(0.7).shift(3.5*LEFT)
+ main3 = TextMobject(r'The ', 'tangent', r' and ', 'normal', r' vectors \\ can be represented as:').scale(0.7).shift(3.5*LEFT)
+ main3.set_color_by_tex_to_color_map({
+ "tangent": YELLOW,
+ "normal": BLUE
+ })
+ main4 = TextMobject(r'These vectors travel along \\ a small interval ', r'$ds$').scale(0.7).shift(1.5*UP + 3*LEFT)
+ main4.set_color_by_tex_to_color_map({
+ "$ds$": GREEN_SCREEN
+ })
+
+ main5 = TextMobject(r'$\kappa = 0.357$').scale(0.7).shift(main.get_center() + np.array([2.4,-0.18,0]))
+
+ nm = Vector((2, -1, 0), color = BLUE).shift(0.005*RIGHT + 0.007*DOWN)
+ nmText = TextMobject(r'$r\prime\prime (t) = \left\langle 2,0,0\right\rangle$').next_to(nm, DOWN+RIGHT, buff = 0).scale(0.7)
+ nm2 = DashedLine((0,0,0),(2, -1, 0), color = GRAY).shift(2*UP + RIGHT)
+ square = Square(fill_color = WHITE, fill_opacity = 0.2).rotate(63*DEGREES).shift(0.5*UP +1.5*RIGHT).scale(1.1)
+ square.set_stroke(width = 0.1)
+ square2 = Square(fill_color = PINK, fill_opacity = 0.2).scale(0.55).rotate(63*DEGREES).move_to((square.get_center() - dot.get_center()) / 2)
+ square2.set_stroke(width = 0.1)
+ arrow = CurvedArrow(square.get_center() + np.array([2,1,0]), square.get_center() + np.array([0.5,0,0]))
+ arrowText = TextMobject(r'$r\prime (t)\times r\prime\prime (t) = 4$').next_to(arrow.get_start(), DOWN+1*RIGHT, buff = 0).scale(0.7)
+
+ text1 = TextMobject(r'$\left|\frac{dT}{ds}\right| = \frac{\left|\frac{dT}{dt}\right|}{\left|\frac{ds}{dt}\right|}$').shift(UP+3*LEFT).scale(0.7)
+ text2 = TextMobject(r'$\left|\frac{dT}{ds}\right| = \frac{\frac{r\prime\prime (t)}{\left| r\prime (t)\right|}\times\frac{r\prime (t)}{\left| r\prime (t)\right|}}{\left|r\prime (t)\right|}$').next_to(text1, DOWN, buff = 0.1).scale(0.7)
+ text3 = TextMobject(r'$= \frac{4}{(4t^{2} + 4)^{\frac{3}{2}}}$ \\ $= \frac{1}{2\sqrt{(1 + (0.5)^{2})^{3}}}$').next_to(text2, DOWN, buff = 0.1).scale(0.7)
+ text4 = TextMobject(r'$ = 0.357$').scale(0.7).next_to(text3, DOWN, buff = 0.2)
+ unit = VGroup(*[tgt, tgt2, nm, nm2])
+
+ tgt2text = TextMobject(r'$\frac{r\prime (t)}{\left| r\prime (t)\right|}$').shift(1.1*UP).scale(0.7).rotate(63*DEGREES )
+ nm2text = TextMobject(r'$\frac{r\prime\prime (t)}{\left| r\prime (t)\right|}$').scale(0.7).shift(0.7*RIGHT+0.8*DOWN).rotate(-25*DEGREES)
+ unit2 = unit.copy().scale(0.5).shift(0.75*LEFT+0.25*DOWN)
+
+ self.play(FadeIn(curve), FadeIn(main))
+ self.wait(1)
+ self.play(ApplyMethod(curve.scale, 3), ApplyMethod(curve.shift, ORIGIN + 3.31*RIGHT))
+ # self.wait(2)
+ self.play(FadeIn(main2), FadeIn(dot))
+ self.play(FadeIn(circle), FadeIn(dl), FadeIn(dltext))
+ self.wait()
+ self.play(ReplacementTransform(main2, main5), FadeIn(main3), FadeOut(circle), FadeOut(dl), FadeOut(dltext), FadeIn(VGroup(*[tgt, tgtText])))
+ self.wait(1)
+ self.play(FadeIn(VGroup(*[nm, nmText])))
+ self.wait(1)
+ self.remove(dot)
+ self.setup()
+ #self.camera_frame.set_width(4)
+ self.activate_zooming(animate = True)
+ self.play(FadeIn(ds), FadeIn(dsl), FadeOut(main3))
+ self.wait(1)
+ self.play(FadeIn(main4))
+ self.play(ApplyMethod(tgt.shift, 0.16*UP + 0.09*RIGHT), ApplyMethod(nm.shift, 0.16*UP + 0.09*RIGHT), run_time = 5)
+ self.wait(1)
+ self.play(FadeOut(ds), FadeOut(dsl), FadeOut(main4), FadeOut(self.zoomed_display, run_time = 1), FadeOut(self.zoomed_camera.frame, run_time = 1))
+ # tgt = tgt.shift(0.16*DOWN + 0.08*LEFT)
+ # nm = nm.shift(0.16*DOWN + 0.08*LEFT)
+ self.play(ApplyMethod(tgt.shift, 0.16*DOWN + 0.09*LEFT, run_time = 1), ApplyMethod(nm.shift, 0.16*DOWN + 0.09*LEFT, run_time = 1))
+ self.play(FadeIn(dot), FadeIn(VGroup(*[tgt2, nm2])))
+ self.wait(1)
+ self.play(FadeIn(VGroup(*[square, arrow, arrowText])))
+ self.wait(1)
+ self.play(FadeIn(unit2), FadeIn(square2))
+ self.wait(1)
+ self.play(FadeIn(VGroup(*[tgt2text, nm2text])))
+ self.wait(1)
+ self.play(FadeIn(text1))
+ self.wait(1)
+ self.play(FadeIn(text2))
+ self.wait(1)
+ self.play(FadeIn(text3))
+ self.wait(1)
+ self.play(FadeIn(text4))
+ self.wait(2)
+ self.play(FadeOut(VGroup(*[main, main5, square2, curve, dot, tgt2text, nm2text, text1, text2, text3, text4, tgt, tgtText,nm, nmText,tgt2, nm2,square, arrow, arrowText,unit2])))
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file5_different_curvature_single_curve.gif b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file5_different_curvature_single_curve.gif
new file mode 100644
index 0000000..3b78b5f
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file5_different_curvature_single_curve.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file5_different_curvature_single_curve.py b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file5_different_curvature_single_curve.py
new file mode 100644
index 0000000..0dc06bb
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/arc-length-and-curvature/file5_different_curvature_single_curve.py
@@ -0,0 +1,76 @@
+from manimlib.imports import *
+
+class GR(GraphScene):
+ CONFIG = {
+ "x_axis_label": "",
+ "y_axis_label": "",
+ "x_min": -4,
+ "x_max": 6,
+ "y_min": -6,
+ "y_max": 10,
+ "graph_origin": ORIGIN,
+ 'x_tick_frequency': 20,
+ 'y_tick_frequency': 20
+ }
+
+ def construct(self):
+
+ self.setup_axes()
+ def curve(x):
+ return 3 - (3653*x**2)/5292 + (277*x**3)/31752 + (13*x**4)/784 - (17*x**5)/5292 + (170*x**6)/63504
+
+ graph = FunctionGraph(curve, x_min=-2, x_max=6, stroke_width = 2, color = BLUE)
+
+ tracker = ValueTracker(-2)
+
+ text = TextMobject(r'$\because R_{1} > R_{2}$, the curvature at \\ point $P_{1}$ is less than that \\ at point $P_{2}$ as $\kappa = \frac{1}{R}$').shift(3.2*LEFT+3*UP).scale(0.6)
+
+ dot1 = Dot((0,3,0), color = YELLOW)
+ dot1label = TextMobject(r'$P_{1}$').next_to(dot1, UP+RIGHT, buff = 0.1)
+ dot2 = Dot((2.9,-0.47, 0), color = YELLOW)
+ dot2label = TextMobject(r'$P_{2}$').next_to(dot2, DOWN, buff = 0.1)
+ dots = VGroup(*[dot1, dot2, dot1label, dot2label])
+
+ def get_tangent_line():
+ line = Line(
+ ORIGIN, 2 * RIGHT,
+ color=RED,
+ stroke_width=4,
+ )
+ dx = 0.0001
+
+ x = tracker.get_value()
+ p0 = np.array([x-dx,curve(x-dx),0])
+ p1 = np.array([x, curve(x), 0])
+ p2 = np.array([x + dx, curve(x + dx), 0])
+
+ angle = angle_of_vector(p2 - p1)
+ line.rotate(angle)
+ line.move_to(p0)
+ return line
+
+ circle1 = Circle(radius = 0.8, color = GREY, opacity = 0.2).shift(2.2*UP)
+ tgt1 = Line((-2,3,0), (2,3,0), color = GREY, opacity = 0.2).scale(0.4)
+
+ r1 = Line(circle1.get_center(), circle1.get_center() + np.array([0,0.8,0]), color=GREEN_SCREEN)
+ r1label = TextMobject(r'$R_{1}$',color=WHITE).next_to(r1, RIGHT, buff = 0.1).scale(0.6)
+
+ curvature1 = VGroup(*[circle1, tgt1, r1, r1label])
+
+ circle2 = Circle(radius = 0.2, color = GREY, opacity = 0.2).shift(0.3*DOWN + 2.9*RIGHT)
+ tgt2 = Line((4,-2,0), (6, -2, 0), color = GREY, opacity = 0.2).scale(0.5).shift(2.1*LEFT + 1.5*UP)
+
+ r2 = Line(circle2.get_center(), circle2.get_center() - np.array([0,0.2,0]), color=GREEN_SCREEN)
+ r2label = TextMobject(r'$R_{2}$', color=WHITE).next_to(r2.get_start(), np.array([0,0,0]), buff = 0).scale(0.4)
+
+ curvature2 = VGroup(*[circle2, tgt2, r2, r2label])
+
+ line = always_redraw(get_tangent_line)
+
+ self.add(graph, line, dots, text)
+ self.wait(1.2)
+ self.play(tracker.set_value, 4, rate_func=smooth, run_time=10)
+ self.play(FadeIn(curvature1), FadeIn(curvature2))
+ self.wait(2)
+ self.play(FadeOut(VGroup(*[curvature1, curvature2, graph, self.axes, line, dots, text])))
+ self.wait()
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/README.md b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/README.md
new file mode 100644
index 0000000..29d2f6a
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/README.md
@@ -0,0 +1,14 @@
+**file1_line_eqn.py**<br>
+![file1_line_eqn.py](https://raw.githubusercontent.com/saarthdeshpande/FSF-mathematics-python-code-archive/master/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file1_line_eqn.gif)
+
+**file2_point_normal_form_plane.py**<br>
+![file2_point_normal_form_plane.py](https://raw.githubusercontent.com/saarthdeshpande/FSF-mathematics-python-code-archive/master/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file2_point_normal_form_plane.gif)
+
+**file3_intercept_form_plane.py**<br>
+![file3_intercept_form_plane.py](https://raw.githubusercontent.com/saarthdeshpande/FSF-mathematics-python-code-archive/master/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file3_intercept_form_plane.gif)
+
+**file4_3d_plane.py**<br>
+![file4_3d_plane.py](https://raw.githubusercontent.com/saarthdeshpande/FSF-mathematics-python-code-archive/master/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file4_3d_plane.gif)
+
+**file5_vector_form_line.py**<br>
+![file5_vector_form_line.py](https://raw.githubusercontent.com/saarthdeshpande/FSF-mathematics-python-code-archive/master/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file5_vector_form_line.gif)
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file1_line_eqn.gif b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file1_line_eqn.gif
new file mode 100644
index 0000000..a8a301a
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file1_line_eqn.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file1_line_eqn.py b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file1_line_eqn.py
new file mode 100644
index 0000000..402775b
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file1_line_eqn.py
@@ -0,0 +1,26 @@
+from manimlib.imports import *
+
+class three(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes()
+ self.set_camera_orientation(phi=14.25* DEGREES,theta=0*DEGREES,distance=8)
+ self.play(FadeIn(axes))
+
+ plane = ParametricSurface(
+ lambda u,v: np.array([
+ 6,
+ 8*v,
+ 3*u
+ ]), u_min = -0.8, u_max = 0.8, fill_opacity = 0.4).rotate(45*DEGREES).move_to(ORIGIN).shift(RIGHT+UP)
+ d2text = TextMobject(r'$\mathbb{R}^{2}: y = mx + c$').shift(3*LEFT + 2*UP).rotate(np.pi/2)
+ d3text = TextMobject(r'$\mathbb{R}^{3}: y = mx + c$').shift(4*RIGHT+3*UP)
+ self.play(FadeIn(plane), FadeIn(d2text))
+ self.wait(3)
+ self.play(FadeOut(d2text))
+ self.move_camera(phi = 60*DEGREES, theta=45*DEGREES,run_time=3)
+ self.begin_ambient_camera_rotation(rate=0.02)
+ self.add_fixed_in_frame_mobjects(d3text)
+ self.play(FadeIn(d3text))
+ self.wait(3)
+ self.play(FadeOut(d3text), FadeOut(plane), FadeOut(axes))
+ self.wait()
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file2_point_normal_form_plane.gif b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file2_point_normal_form_plane.gif
new file mode 100644
index 0000000..e651be0
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file2_point_normal_form_plane.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file2_point_normal_form_plane.py b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file2_point_normal_form_plane.py
new file mode 100644
index 0000000..122a9ff
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file2_point_normal_form_plane.py
@@ -0,0 +1,39 @@
+from manimlib.imports import *
+
+class pointnormal(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes()
+
+ self.set_camera_orientation(phi = 75*DEGREES, theta=45*DEGREES)
+ normal = Arrow((0,-0.15,-0.25), (-3,0,3), color = YELLOW)
+ plane1 = Polygon(np.array([1,0,2]),np.array([-1,2.5,1]),np.array([-3,2,1]),np.array([-1,-1,2]), color = GREEN_E, fill_color = WHITE, fill_opacity=0.5)
+ plane2 = Polygon(np.array([1,0,2]),np.array([-1,2.5,1]),np.array([-3,2,1]),np.array([-1,-1,2]), color = BLUE, fill_color = WHITE, fill_opacity=0.3)
+ normalLabel = TextMobject(r'$\overrightarrow{n}$').shift((2,2.5,0))
+ pointLabel = TextMobject(r'$P$').shift((2,1.2,0))
+ xlabel = TextMobject(r'$x$').shift(4.5*LEFT + 1.7*DOWN)
+ ylabel = TextMobject(r'$y$').shift(4.5*RIGHT + 1.8*DOWN)
+ zlabel = TextMobject(r'$z$').shift(3.3*UP+0.5*RIGHT)
+
+ normaltext = TextMobject(r'Consider an arbitrary \\ normal vector $\overrightarrow{n}$').scale(0.6).shift(2*UP + 2.5*LEFT)
+ planetext = TextMobject(r'A single vector is normal \\ to infinitely many planes.').scale(0.6).shift(2*UP + 2.5*LEFT)
+ pointtext = TextMobject(r'Given a fixed point $P$, \\ a plane is obtained as:').scale(0.6).shift(2*UP + 2.5*LEFT)
+
+ point = Dot(color = RED).shift((1.6,1.3,0))
+ self.play(FadeIn(axes))
+ self.add_fixed_in_frame_mobjects(xlabel, ylabel, zlabel)
+ self.wait(1)
+ self.play(FadeIn(normal))
+ self.add_fixed_in_frame_mobjects(normalLabel, normaltext)
+ self.play(FadeIn(normaltext))
+ self.wait(2)
+ self.add_fixed_in_frame_mobjects(planetext)
+ self.play(ReplacementTransform(normaltext, planetext), run_time=0.01)
+ self.play(MoveAlongPath(plane1, normal), run_time = 6)
+ self.add_fixed_in_frame_mobjects(pointtext)
+ self.play(ReplacementTransform(planetext, pointtext))
+ self.add_fixed_in_frame_mobjects(point, pointLabel)
+ self.wait(1)
+ self.play(Transform(plane1, plane2))
+ self.wait(2)
+ self.play(FadeOut(axes), FadeOut(plane2), FadeOut(plane1), FadeOut(point), FadeOut(pointLabel), FadeOut(normal), FadeOut(normalLabel), FadeOut(planetext), FadeOut(pointtext), FadeOut(normaltext), FadeOut(VGroup(*[xlabel, ylabel, zlabel])))
+ self.wait(1)
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file3_intercept_form_plane.gif b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file3_intercept_form_plane.gif
new file mode 100644
index 0000000..a8b7d75
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file3_intercept_form_plane.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file3_intercept_form_plane.py b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file3_intercept_form_plane.py
new file mode 100644
index 0000000..258ac3c
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file3_intercept_form_plane.py
@@ -0,0 +1,29 @@
+from manimlib.imports import *
+
+class pointnormal(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes(x_min = 0, y_min = 0, z_min = 0)
+ self.set_camera_orientation(phi = 75*DEGREES, theta=45*DEGREES)
+
+ plane1 = Polygon(np.array([2,-3,2.5]),np.array([-1.45,2,2.5]),np.array([-0.5,4.5,-0.1]),np.array([3.5,-1,-0.2]), fill_color = WHITE, fill_opacity=0.3)
+
+ xlabel = TextMobject(r'$x$').shift(5*LEFT + 1.5*DOWN)
+ ylabel = TextMobject(r'$y$').shift(5*RIGHT + 1.5*DOWN)
+ zlabel = TextMobject(r'$z$').shift(3.3*UP + 0.5*LEFT)
+
+ zintercept = Dot().shift(2.5*UP)
+ zinterceptlabel = TextMobject(r'$(0,0,c\prime)$').shift(2.8*UP + RIGHT).scale(0.7)
+
+ yintercept = Dot().shift(3.7*RIGHT + 0.925*DOWN)
+ yinterceptlabel = TextMobject(r'$(0,b\prime ,0)$').shift(3.7*RIGHT+1.5*DOWN).scale(0.7)
+
+ xintercept = Dot().shift(2.9*LEFT + 0.75*DOWN)
+ xinterceptlabel = TextMobject(r'$(a\prime ,0,0)$').shift(3*LEFT+1.3*DOWN).scale(0.7)
+
+ self.play(FadeIn(axes), FadeIn(plane1))
+ self.add_fixed_in_frame_mobjects(xlabel, ylabel, zlabel, zintercept, zinterceptlabel, yintercept, yinterceptlabel, xintercept, xinterceptlabel)
+ self.wait(2)
+ self.remove(zintercept, zinterceptlabel, yintercept, yinterceptlabel, xintercept, xinterceptlabel, xlabel, ylabel, zlabel)
+ self.begin_ambient_camera_rotation(rate=0.5)
+ self.wait(5)
+ self.play(FadeOut(axes), FadeOut(plane1))
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file4_3d_plane.gif b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file4_3d_plane.gif
new file mode 100644
index 0000000..b4c259e
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file4_3d_plane.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file4_3d_plane.py b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file4_3d_plane.py
new file mode 100644
index 0000000..26ad825
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file4_3d_plane.py
@@ -0,0 +1,49 @@
+from manimlib.imports import *
+
+class pointnormal(ThreeDScene):
+ CONFIG = {
+ 'x_axis_label': '$x$',
+ 'y_axis_label': '$y$'
+ }
+ def construct(self):
+ axes = ThreeDAxes()
+ axes.add(axes.get_axis_labels())
+ self.set_camera_orientation(phi = 75*DEGREES, theta=45*DEGREES)
+
+ plane = Polygon(
+ np.array([2,0,2.7]),
+ np.array([0,0,0.4]),
+ np.array([-3.2,0,0.55]),
+ np.array([-3,-2,2.5]),
+ fill_color = WHITE, fill_opacity = 0.25)
+
+ normal = Arrow((0.25,2,0), (1.5,3.5,0))
+ normalLabel = TextMobject(r'$\overrightarrow{n}$').shift((1.5,2.8,0))
+
+ point = Dot(color = RED).shift((1.6,1.3,0))
+ pointLabel = TextMobject(r'$P_{0}$').shift((2,1.2,0))
+
+ point2 = Dot(color = RED).shift((-0.2,1.8,0))
+ point2Label = TextMobject(r'$P$').shift((-0.3,2,0))
+
+ arrow1 = Arrow((0,-0.25,-0.2), (-2.55,0,1), color = YELLOW).set_stroke(width=3)
+ arrow2 = Arrow((0,0,-0.25), (0.3,0,2), color = YELLOW).set_stroke(width=3)
+ res = Arrow((1.8,1.23,0),(-0.35,1.85,0), color = BLUE).set_stroke(width=3)
+
+ arrow1label = TextMobject(r'$\overrightarrow{r_{0}}$').next_to(arrow2, UP).shift(RIGHT + 0.16*DOWN).scale(0.7)
+ arrow2label = TextMobject(r'$\overrightarrow{r}$').next_to(arrow2, UP).shift(0.7*LEFT).scale(0.7)
+ reslabel = TextMobject(r'$\overrightarrow{r} - \overrightarrow{r_{0}}$').next_to(arrow2, UP).shift(0.7*RIGHT + 1.2*UP).scale(0.7)
+
+ self.play(FadeIn(axes), FadeIn(plane))
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(normal, normalLabel)
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(point, pointLabel)
+ self.add_fixed_in_frame_mobjects(point2, point2Label)
+ self.play(Write(arrow1), Write(arrow2))
+ self.add_fixed_in_frame_mobjects(arrow2label, arrow1label)
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(res, reslabel)
+ self.play(Write(res), FadeIn(reslabel))
+ self.wait(1)
+ self.play(FadeOut(axes), FadeOut(plane), FadeOut(point), FadeOut(pointLabel), FadeOut(normal), FadeOut(normalLabel), FadeOut(point2), FadeOut(point2Label), FadeOut(arrow1label), FadeOut(arrow2label), FadeOut(reslabel), FadeOut(arrow1), FadeOut(arrow2), FadeOut(res)) \ No newline at end of file
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file5_vector_form_line.gif b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file5_vector_form_line.gif
new file mode 100644
index 0000000..b6fdb51
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file5_vector_form_line.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file5_vector_form_line.py b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file5_vector_form_line.py
new file mode 100644
index 0000000..e25c4eb
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/equations-of-planes-and-lines/file5_vector_form_line.py
@@ -0,0 +1,47 @@
+from manimlib.imports import *
+
+class line_(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes()
+ xlabel = TextMobject(r'$x$').shift(4.5*LEFT + 1.7*DOWN)
+ ylabel = TextMobject(r'$y$').shift(4.5*RIGHT + 1.8*DOWN)
+ zlabel = TextMobject(r'$z$').shift(3.3*UP+0.5*RIGHT)
+
+ self.set_camera_orientation(phi = 75*DEGREES, theta=45*DEGREES)
+ pointLabel = TextMobject(r'$P$').shift((2.28,2.12,0)).scale(0.7)
+ point = Dot(color = RED).shift((1.95,1.9,0))
+
+ vlabel = TextMobject(r'$\overrightarrow{v}$').shift((0.5,1.3,0)).scale(0.7)
+
+ inf_text = TextMobject(r'Infinitely many lines pass \\ through a single point.').scale(0.6).shift(2*UP + 2.5*LEFT)
+ pointtext = TextMobject(r'Given a direction vector $\overrightarrow{v}$, \\ a line is obtained as:').scale(0.6).shift(2*UP + 2.5*LEFT)
+
+
+ line = Line((0.7,0.7,0), (2,3,0)).shift(0.06*UP+0.6*RIGHT)
+ v = Vector((0.8,1,0), color = GREEN_E)
+ #finalLine = Line((-1.56,0,0.5),(-4,0,2.42), color = YELLOW)
+ finalLine = Line((1,0.8,0),(3,3,0), color = YELLOW).shift(0.05*LEFT)
+ self.play(FadeIn(axes))
+ self.add_fixed_in_frame_mobjects(zlabel, ylabel, xlabel)
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(point, pointLabel)
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(inf_text)
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(line)
+
+ for i in range(9):
+ self.play(ApplyMethod(line.rotate, -np.pi/12), run_time = 0.7)
+ if i == 8:
+ self.add_fixed_in_frame_mobjects(pointtext)
+ self.play(ReplacementTransform(inf_text, pointtext))
+ self.add_fixed_in_frame_mobjects(v, vlabel)
+ # if i == 13:
+ # self.add_fixed_in_frame_mobjects(pointtext)
+
+ self.add_fixed_in_frame_mobjects(finalLine)
+ self.play(FadeIn(finalLine))
+ self.play(Transform(line, finalLine), run_time = 4)
+ #self.play(FadeOut(line), FadeIn(finalLine))
+ self.wait(1.5)
+ self.play(FadeOut(VGroup(*[axes, xlabel, ylabel, zlabel, finalLine, v, vlabel, point, pointLabel, pointtext, line])))
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/README.md b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/README.md
new file mode 100644
index 0000000..8a47a0e
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/README.md
@@ -0,0 +1,11 @@
+**file1_parametric_circle..py** <br>
+![file1_parametric_circle.py](https://raw.githubusercontent.com/saarthdeshpande/FSF-mathematics-python-code-archive/master/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/file1_parametric_circle.gif)
+
+**file2_cycloid_manim.py** <br>
+![file2_cycloid_manim.py](https://raw.githubusercontent.com/saarthdeshpande/FSF-mathematics-python-code-archive/master/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/file2_cycloid_manim.gif)
+
+**file3_brachistochrone.py** <br>
+![file3_brachistochrone.py](https://raw.githubusercontent.com/saarthdeshpande/FSF-mathematics-python-code-archive/master/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/file3_brachistochrone.gif)
+
+**file4_helix_visualization.py** <br>
+![file4_helix_visualization.py](https://raw.githubusercontent.com/saarthdeshpande/FSF-mathematics-python-code-archive/master/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/file4_helix_visualization.gif)
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/file1_parametric_circle.gif b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/file1_parametric_circle.gif
new file mode 100644
index 0000000..732b6bb
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/file1_parametric_circle.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/file1_parametric_circle.py b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/file1_parametric_circle.py
new file mode 100644
index 0000000..37d079e
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/file1_parametric_circle.py
@@ -0,0 +1,81 @@
+from manimlib.imports import *
+
+class parametricCircle(ThreeDScene, GraphScene):
+ def construct(self):
+ self.x_min = -5
+ self.y_min = -5
+ self.graph_origin = ORIGIN
+ self.x_max = 5
+ self.y_max = 5
+ self.x_axis_label = ""
+ self.y_axis_label = ""
+ self.x_axis_width = 10
+ self.y_axis_height = 10
+ self.y_tick_frequency = 1.9
+ self.x_tick_frequency = 1.4
+
+ axes = []
+
+ # self.setup_axes()
+ ax = Axes(y_tick_frequency = 1, x_axis_width = 10, y_axis_height = 10, y_min = -5, x_max = 5, y_max = 5, x_tick_frequency = 1, x_axis_label = "", y_axis_label = "", x_min = -5, )
+ ax.scale(0.5).shift(3*LEFT)
+ axes.append(ax)
+ self.setup_axes()
+ self.axes.scale(0.3).shift(3*RIGHT + 2*UP)
+ axes.append(self.axes)
+ self.setup_axes()
+ self.axes.scale(0.3).shift(3*RIGHT + 2*DOWN)
+ axes.append(self.axes)
+
+ axes = VGroup(*axes)
+ t_value = ValueTracker(-3.14)
+ t_tex = DecimalNumber(t_value.get_value()).add_updater(lambda v: v.set_value(t_value.get_value()))
+ t_label = TexMobject("t = ")
+ group = VGroup(t_tex,t_label).shift(3*DOWN)
+ t_label.next_to(t_tex,LEFT, buff=0.2,aligned_edge=t_label.get_bottom())
+
+ asint_text = TextMobject(r'$x = a\sin{t}$').scale(0.7).shift(4*RIGHT + 3*UP)
+ xlabel1 = TextMobject(r'$x$').shift(3.3*RIGHT + 3.7*UP).scale(0.7)
+ tlabel1 = TextMobject(r'$t$').shift(4.8*RIGHT + 2*UP).scale(0.7)
+ up_text = VGroup(*[asint_text, xlabel1, tlabel1])
+ asint = ParametricFunction(
+ lambda t: np.array([
+ t,
+ 2*np.sin(t),
+ 0
+ ]), t_min = -np.pi, t_max = np.pi, color = GREEN_E
+ ).shift(3*RIGHT + 2*UP).scale(0.4)
+
+ acost_text = TextMobject(r'$y = a\cos{t}$').scale(0.7).shift(4*RIGHT + DOWN)
+ ylabel1 = TextMobject(r'$y$').shift(3.3*RIGHT+0.3*DOWN).scale(0.7)
+ tlabel2 = TextMobject(r'$t$').shift(4.8*RIGHT + 2*DOWN).scale(0.7)
+ down_text = VGroup(*[acost_text, ylabel1, tlabel2])
+ acost = ParametricFunction(
+ lambda t: np.array([
+ t,
+ 2*np.cos(t),
+ 0
+ ]), t_min = -np.pi, t_max = np.pi, color = BLUE
+ ).shift(3*RIGHT + 2*DOWN).scale(0.4)
+
+ up_dot = Dot(color = RED)
+ down_dot = Dot(color = RED)
+ circle_dot = Dot(color = RED)
+
+ ylabel2 = TextMobject(r'$y$').scale(0.7).shift(3*UP + 3*LEFT)
+ xlabel2 = TextMobject(r'$x$').scale(0.7)
+ ellipse_text = TextMobject(r'$x = a\sin{t}$ \\ $y = a\cos{t}$').scale(0.7).shift(2*UP + 1.3*LEFT)
+ main_text = VGroup(*[xlabel2, ylabel2, ellipse_text])
+ circle = ParametricFunction(
+ lambda t: np.array([
+ np.cos(t),
+ np.sin(t),
+ 0
+ ]), t_min = -np.pi, t_max = np.pi, color = WHITE
+ ).shift(3*LEFT)
+ self.play(FadeIn(axes), FadeIn(asint), FadeIn(acost), FadeIn(circle), FadeIn(up_text), FadeIn(down_text), FadeIn(main_text), FadeIn(group))
+ self.wait(1)
+ self.play(MoveAlongPath(up_dot, asint, run_time = 7), MoveAlongPath(down_dot, acost, run_time = 7), MoveAlongPath(circle_dot, circle, run_time = 7), t_value.set_value,3.14, rate_func=linear, run_time=7)
+ self.wait(1)
+ self.play(FadeOut(VGroup(*[axes, asint, acost, circle, up_text, down_text, main_text, up_dot, down_dot, circle_dot, group])))
+ self.wait(1)
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/file2_cycloid_manim.gif b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/file2_cycloid_manim.gif
new file mode 100644
index 0000000..e68b841
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/file2_cycloid_manim.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/file2_cycloid_manim.py b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/file2_cycloid_manim.py
new file mode 100644
index 0000000..7b6c0d1
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/file2_cycloid_manim.py
@@ -0,0 +1,46 @@
+from manimlib.imports import *
+
+t_offset = 0
+c_t = 0
+
+class cycloid(Scene):
+ def construct(self):
+
+ cycl = ParametricFunction(
+ lambda t: np.array([
+ t - np.sin(t),
+ 1 - np.cos(t),
+ 0
+ ]), t_min = -2.75*np.pi, t_max = 3*np.pi, color = BLUE
+ ).shift(0.73*RIGHT)
+ wheel_radius = 1
+ wheel_function_path = lambda x : 0 + wheel_radius
+
+ line = FunctionGraph(lambda x : 0, color = BLACK)
+ wheel_path = FunctionGraph(wheel_function_path)
+
+ velocity_factor = 0.25
+ frame_rate = self.camera.frame_rate
+ self.dt = 1 / frame_rate
+
+ wheel = Circle(color = BLACK, radius = 1)
+ dot = Dot(radius = 0.16, color = RED)
+ #dot.move_to(wheel.get_arc_center() + np.array([0,2,0]))
+
+ def update_dot(mob,dt):
+ global t_offset,c_t
+ if dt == 0 and c_t == 0:
+ rate= - velocity_factor * self.dt
+ c_t += 1
+ else:
+ rate = - dt*velocity_factor
+ if dt > 0:
+ c_t = 0
+ mob.move_to(wheel.point_from_proportion(((t_offset + rate))%1))
+ t_offset += rate
+ #self.add(mob.copy())
+
+ #dot.move_to(wheel.get_arc_center() + np.array([0,2,0]))
+ dot.add_updater(update_dot)
+ self.add(wheel,dot, line, cycl)
+ self.play(MoveAlongPath(wheel, wheel_path, run_time = 9, rate_func = linear))
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/file3_brachistochrone.gif b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/file3_brachistochrone.gif
new file mode 100644
index 0000000..8daf4c0
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/file3_brachistochrone.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/file3_brachistochrone.py b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/file3_brachistochrone.py
new file mode 100644
index 0000000..633e500
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/file3_brachistochrone.py
@@ -0,0 +1,13 @@
+from manimlib.imports import *
+
+class brachistochrone(Scene):
+ def construct(self):
+ curve = ParametricFunction(
+ lambda t: np.array([
+ 0.5*(t - np.sin(t)),
+ 0.5*(1 - np.cos(t)),
+ 0
+ ]), t_max = np.pi
+ ).scale(5).rotate(540*DEGREES)
+ dot = Dot(color = RED, radius = 0.2)
+ self.play(FadeIn(curve), MoveAlongPath(dot, curve, run_time = 2))
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/file4_helix_visualization.gif b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/file4_helix_visualization.gif
new file mode 100644
index 0000000..16d2509
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/file4_helix_visualization.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/file4_helix_visualization.py b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/file4_helix_visualization.py
new file mode 100644
index 0000000..eddd3fe
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/general-parametric-curves/file4_helix_visualization.py
@@ -0,0 +1,31 @@
+from manimlib.imports import *
+
+class helix_(ThreeDScene):
+ CONFIG = {
+ "x_min": -6,
+ "x_max": 6,
+ "y_min": -6,
+ "y_max": 6,
+ "graph_origin": ORIGIN
+ }
+ def construct(self):
+ axes = ThreeDAxes()
+ helix = ParametricFunction(
+ lambda t: np.array([
+ 1.5*np.cos(TAU*t),
+ 1.5*np.sin(TAU*t),
+ 2*t
+ ]), t_min = -1, t_max = 2, color = RED
+ )
+ cylinder = ParametricSurface(
+ lambda u, v: np.array([
+ 1.5*np.cos(TAU*v),
+ 1.5*np.sin(TAU*v),
+ 2*u
+ ]), u_min = -1, u_max = 2, fill_opacity = -.4, fill_color = WHITE, color = WHITE
+ )
+ self.set_camera_orientation(phi=60* DEGREES,theta=45*DEGREES)
+ self.play(FadeIn(axes), FadeIn(cylinder), ShowCreation(helix, run_time = 4))
+ self.begin_ambient_camera_rotation(rate=0.5)
+ self.wait(5)
+ self.play(FadeOut(axes),FadeOut(helix), FadeOut(cylinder))
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/README.md b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/README.md
new file mode 100644
index 0000000..42f5df1
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/README.md
@@ -0,0 +1,11 @@
+**file1_parametric_ellipse.py** <br>
+![file1_parametric_ellipse.py](https://raw.githubusercontent.com/saarthdeshpande/FSF-mathematics-python-code-archive/master/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file1_parametric_ellipse.gif)
+
+**file2_parametric_helix.py** <br>
+![file2_parametric_helix.py](https://raw.githubusercontent.com/saarthdeshpande/FSF-mathematics-python-code-archive/master/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file2_parametric_helix.gif)
+
+**file3_circletosphere.py** <br>
+![file3_circletosphere.py](https://raw.githubusercontent.com/saarthdeshpande/FSF-mathematics-python-code-archive/master/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file3_circletosphere.gif)
+
+**file4_cone.py** <br>
+![file4_cone.py](https://raw.githubusercontent.com/saarthdeshpande/FSF-mathematics-python-code-archive/master/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file4_cone.gif)
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file1_parametric_ellipse.gif b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file1_parametric_ellipse.gif
new file mode 100644
index 0000000..90c0349
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file1_parametric_ellipse.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file1_parametric_ellipse.py b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file1_parametric_ellipse.py
new file mode 100644
index 0000000..1ce29d7
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file1_parametric_ellipse.py
@@ -0,0 +1,78 @@
+from manimlib.imports import *
+
+class parametricEllipse(ThreeDScene, GraphScene):
+ def construct(self):
+ self.x_min = -5
+ self.y_min = -5
+ self.graph_origin = ORIGIN
+ self.x_max = 5
+ self.y_max = 5
+ self.x_axis_label = ""
+ self.y_axis_label = ""
+ self.x_axis_width = 10
+ self.y_axis_height = 10
+
+ axes = []
+
+ self.setup_axes()
+ self.axes.scale(0.5).shift(3*LEFT)
+ axes.append(self.axes)
+ self.setup_axes()
+ self.axes.scale(0.3).shift(3*RIGHT + 2*UP)
+ axes.append(self.axes)
+ self.setup_axes()
+ self.axes.scale(0.3).shift(3*RIGHT + 2*DOWN)
+ axes.append(self.axes)
+
+ axes = VGroup(*axes)
+ t_value = ValueTracker(-3.14)
+ t_tex = DecimalNumber(t_value.get_value()).add_updater(lambda v: v.set_value(t_value.get_value()))
+ t_label = TexMobject("t = ")
+ group = VGroup(t_tex,t_label).shift(3*DOWN)
+ t_label.next_to(t_tex,LEFT, buff=0.2,aligned_edge=t_label.get_bottom())
+
+ asint_text = TextMobject(r'$x = a\sin{t}$').scale(0.7).shift(4*RIGHT + 3*UP)
+ xlabel1 = TextMobject(r'$x$').shift(3.3*RIGHT + 3.7*UP).scale(0.7)
+ tlabel1 = TextMobject(r'$t$').shift(4.8*RIGHT + 2*UP).scale(0.7)
+ up_text = VGroup(*[asint_text, xlabel1, tlabel1])
+ asint = ParametricFunction(
+ lambda t: np.array([
+ t,
+ np.sin(t),
+ 0
+ ]), t_min = -np.pi, t_max = np.pi, color = GREEN_E
+ ).shift(3*RIGHT + 2*UP).scale(0.4)
+
+ bcost_text = TextMobject(r'$y = b\cos{t}$').scale(0.7).shift(4*RIGHT + DOWN)
+ ylabel1 = TextMobject(r'$y$').shift(3.3*RIGHT+0.3*DOWN).scale(0.7)
+ tlabel2 = TextMobject(r'$t$').shift(4.8*RIGHT + 2*DOWN).scale(0.7)
+ down_text = VGroup(*[bcost_text, ylabel1, tlabel2])
+ bcost = ParametricFunction(
+ lambda t: np.array([
+ t,
+ 1.5*np.cos(t),
+ 0
+ ]), t_min = -np.pi, t_max = np.pi, color = BLUE
+ ).shift(3*RIGHT + 2*DOWN).scale(0.4)
+
+ up_dot = Dot(color = RED)
+ down_dot = Dot(color = RED)
+ ellipse_dot = Dot(color = RED)
+
+ ylabel2 = TextMobject(r'$y$').scale(0.7).shift(3*UP + 3*LEFT)
+ xlabel2 = TextMobject(r'$x$').scale(0.7)
+ ellipse_text = TextMobject(r'$x = a\sin{t}$ \\ $y = b\cos{t}$').scale(0.7).shift(2*UP + 1.3*LEFT)
+ main_text = VGroup(*[xlabel2, ylabel2, ellipse_text])
+ ellipse = ParametricFunction(
+ lambda t: np.array([
+ 1.5*np.cos(t),
+ np.sin(t),
+ 0
+ ]), t_min = -np.pi, t_max = np.pi, color = WHITE
+ ).shift(3*LEFT)
+ self.play(FadeIn(axes), FadeIn(asint), FadeIn(bcost), FadeIn(ellipse), FadeIn(up_text), FadeIn(down_text), FadeIn(main_text), FadeIn(group))
+ self.wait(1)
+ self.play(MoveAlongPath(up_dot, asint, run_time = 7), MoveAlongPath(down_dot, bcost, run_time = 7), MoveAlongPath(ellipse_dot, ellipse, run_time = 7), t_value.set_value,3.14, rate_func=linear, run_time=7)
+ self.wait(1)
+ self.play(FadeOut(VGroup(*[axes, asint, bcost, ellipse, up_text, down_text, main_text, up_dot, down_dot, ellipse_dot, group])))
+ self.wait(1)
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file2_parametric_helix.gif b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file2_parametric_helix.gif
new file mode 100644
index 0000000..4f349b1
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file2_parametric_helix.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file2_parametric_helix.py b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file2_parametric_helix.py
new file mode 100644
index 0000000..3791752
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file2_parametric_helix.py
@@ -0,0 +1,91 @@
+from manimlib.imports import *
+
+class parametricHelix(ThreeDScene, GraphScene):
+ def construct(self):
+ self.x_min = -5
+ self.y_min = -4
+ self.graph_origin = ORIGIN
+ self.x_max = 5
+ self.y_max = 4
+ self.x_axis_label = ""
+ self.y_axis_label = ""
+ self.x_axis_width = 10
+ self.y_axis_height = 7.5
+ ax1 = ThreeDAxes().scale(0.65).shift(2.6*RIGHT+DOWN+np.array([0,0,0.5]))
+ axes_group = []
+
+ self.setup_axes()
+ self.axes.shift(3*RIGHT + 2*UP).scale(0.3)
+ axes_group.append(self.axes)
+
+ self.setup_axes()
+ self.axes.shift(3*RIGHT + 2*DOWN).scale(0.3)
+ axes_group.append(self.axes)
+
+ axes_group = VGroup(*axes_group)
+
+ asint_text = TextMobject(r'$x = a\sin{t}$').scale(0.7).shift(4*RIGHT + 3*UP)
+ xlabel1 = TextMobject(r'$x$').shift(3.3*RIGHT + 3.7*UP).scale(0.7)
+ tlabel1 = TextMobject(r'$t$').shift(5*RIGHT + 2*UP).scale(0.7)
+ up_text = VGroup(*[asint_text, xlabel1, tlabel1])
+ asint = ParametricFunction(
+ lambda t: np.array([
+ t,
+ np.sin(t),
+ 0
+ ]), t_min = -4*np.pi, t_max = 4*np.pi, color = GREEN_E
+ ).shift(3*RIGHT + 2*UP).scale(0.12)
+
+ acost_text = TextMobject(r'$y = a\cos{t}$').scale(0.7).shift(4*RIGHT + DOWN)
+ ylabel1 = TextMobject(r'$y$').shift(3.3*RIGHT+0.3*DOWN).scale(0.7)
+ tlabel2 = TextMobject(r'$t$').shift(5*RIGHT + 2*DOWN).scale(0.7)
+ down_text = VGroup(*[acost_text, ylabel1, tlabel2])
+ acost = ParametricFunction(
+ lambda t: np.array([
+ t,
+ np.cos(t),
+ 0
+ ]), t_min = -4*np.pi, t_max = 4*np.pi, color = BLUE
+ ).shift(3*RIGHT + 2*DOWN).scale(0.12)
+
+ up_dot = Dot(color = RED).scale(0.6)
+ down_dot = Dot(color = RED).scale(0.6)
+ helix_dot = Dot(radius = 0.16, color = RED)
+
+ zlabel = TextMobject(r'$z$').scale(0.7).shift(3*UP + 2.8*LEFT)
+ ylabel2 = TextMobject(r'$y$').scale(0.7).shift(0.3*DOWN+0.15*RIGHT)
+ xlabel2 = TextMobject(r'$x$').scale(0.7).shift(0.5*DOWN + 6.4*LEFT)
+ helix_text = TextMobject(r'$x = a\sin{t}$ \\ $y = a\cos{t}$ \\ $z = ct$').scale(0.7).shift(2.3*UP + 1.3*LEFT)
+ main_text = VGroup(*[xlabel2, ylabel2, zlabel, helix_text])
+ helix = ParametricFunction(
+ lambda t: np.array([
+ np.cos(TAU*t),
+ np.sin(TAU*t),
+ 0.4*t
+ ]), t_min = -2*np.pi/3, t_max = 1.8*np.pi/3, color = WHITE
+ ).shift(ax1.get_center())
+
+ self.set_camera_orientation(phi = 75*DEGREES, theta=45*DEGREES)
+
+ t_tracker = ValueTracker(-12.56)
+ t=t_tracker.get_value
+
+ t_label = TexMobject(
+ "t = ",color=WHITE
+ ).next_to(helix_text,DOWN, buff=0.2).scale(0.6)
+
+ t_text = always_redraw(
+ lambda: DecimalNumber(
+ t(),
+ color=WHITE,
+ ).next_to(t_label, RIGHT, buff=0.2)
+ ).scale(0.6)
+
+ group = VGroup(t_text,t_label).scale(1.5).move_to(ORIGIN).shift(2*DOWN)
+ self.add_fixed_in_frame_mobjects(axes_group, main_text, up_text, down_text, acost, asint)
+ self.play(FadeIn(ax1), FadeIn(axes_group), FadeIn(asint), FadeIn(acost), FadeIn(helix), FadeIn(up_text), FadeIn(down_text), FadeIn(main_text))
+ #self.begin_ambient_camera_rotation(rate = 0.06)
+ self.add_fixed_in_frame_mobjects(up_dot, down_dot, group)
+ self.play(MoveAlongPath(up_dot, asint, run_time = 8), MoveAlongPath(down_dot, acost, run_time = 8), MoveAlongPath(helix_dot, helix, run_time = 8), t_tracker.set_value,12.56, rate_func=linear, run_time=8)
+ self.play(FadeOut(VGroup(*[ax1, axes_group, asint, acost, helix, up_text, down_text, main_text, up_dot, down_dot, helix_dot, group])))
+ self.wait(1)
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file3_circletosphere.gif b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file3_circletosphere.gif
new file mode 100644
index 0000000..d6a8afc
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file3_circletosphere.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file3_circletosphere.py b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file3_circletosphere.py
new file mode 100644
index 0000000..6c0e810
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file3_circletosphere.py
@@ -0,0 +1,45 @@
+from manimlib.imports import *
+
+class sphere(GraphScene, ThreeDScene):
+ CONFIG = {
+ 'x_min': -10,
+ 'x_max': 10,
+ 'y_min': -10,
+ 'y_max': 10,
+ 'graph_origin': ORIGIN,
+ "x_axis_width": 10,
+ "y_axis_height": 10,
+ }
+ def construct(self):
+ XTD = self.x_axis_width/(self.x_max- self.x_min)
+ YTD = self.y_axis_height/(self.y_max- self.y_min)
+ circleeqn = TextMobject(r'Hence, $x^{2} + y^{2} = 2(r^{2} - u^{2})$')
+ plottext = TextMobject(r'$x = \sqrt{r^{2} - u^{2}}cos\theta$ \\ $y = \sqrt{r^{2} - u^{2}}sin\theta$').shift(2*UP + 3*RIGHT)
+
+
+ self.setup_axes()
+ self.play(FadeIn(self.axes), FadeIn(plottext))
+
+ dots = []
+ for t in range(19):
+ dot = Dot().shift((3*XTD*np.cos(t), 3*YTD*np.sin(t),0))
+ dots.append(dot)
+ self.play(FadeIn(dot), run_time = 0.2)
+ dots = VGroup(*dots)
+ circle = Circle(radius = 3*XTD).set_color(WHITE).set_stroke(width = 10)
+ self.play(FadeIn(circle), FadeOut(dots), FadeOut(plottext))
+ self.wait(2)
+
+
+ axes = ThreeDAxes(**self.CONFIG)
+ sph = Sphere(radius = 3).scale(0.5)
+ text2 = TextMobject(r'Setting $u = 3$,\\$z = u$').shift(4*YTD*UP + 5*XTD*RIGHT)
+
+ self.play(Transform(self.axes,axes), ReplacementTransform(circle, sph))
+ self.add(text2)
+ self.wait(2)
+ self.remove(text2)
+ self.move_camera(phi = 60*DEGREES, theta=45*DEGREES,run_time=5)
+ self.begin_ambient_camera_rotation(rate=0.03)
+ self.play(FadeOut(axes), FadeOut(sph), FadeOut(self.axes))
+ self.wait(1)
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file4_cone.gif b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file4_cone.gif
new file mode 100644
index 0000000..b126d20
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file4_cone.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file4_cone.py b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file4_cone.py
new file mode 100644
index 0000000..e6ae1c6
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file4_cone.py
@@ -0,0 +1,33 @@
+from manimlib.imports import *
+
+class cone(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes()
+ eqn = TextMobject(r'$z^{2} = x^{2} + y^{2}$')
+
+ conecurve = ParametricFunction(
+ lambda t: np.array([
+ t*np.cos(TAU*t),
+ t*np.sin(TAU*t),
+ t
+ ]), t_min = -2.6, t_max = 2.6
+ ).scale(0.85)
+
+ conesurface = ParametricSurface(
+ lambda u,v: np.array([
+ 3*np.sin(u)*np.cos(TAU*v),
+ 3*np.sin(u)*np.sin(TAU*v),
+ 2.7*u
+ ]), u_min = -1
+ ).scale(0.85)
+
+ self.play(FadeIn(eqn))
+ self.wait(2)
+ self.play(FadeOut(eqn))
+ self.set_camera_orientation(phi = 75*DEGREES, theta=50*DEGREES)
+ self.play(FadeIn(axes), ShowCreation(conecurve, run_time = 3))
+ self.play(FadeOut(conecurve), FadeIn(conesurface))
+ self.begin_ambient_camera_rotation(rate=0.03)
+ self.wait(2)
+ self.play(FadeOut(axes), FadeOut(conesurface))
+ self.wait(2)
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/README.md b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/README.md
new file mode 100644
index 0000000..7874f43
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/README.md
@@ -0,0 +1,15 @@
+**file1_tnb_creation.py**<br>
+![file1_tnb_creation.py](https://github.com/saarthdeshpande/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file1_tnb_creation.gif)
+
+
+**file2_tnb_basic.py** <br>
+![file2_tnb_basic.py](https://github.com/saarthdeshpande/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file2_tnb_basic.gif)
+
+**file3_tnb_frame_manim.py** <br>
+![file3_tnb_frame_manim.py](https://github.com/saarthdeshpande/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file3_tnb_frame_manim.gif)
+
+**file4_fs1.py** <br>
+![file4_fs1.py](https://github.com/saarthdeshpande/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file4_fs1.gif)
+
+**file5_fs2.py** <br>
+![file5_fs2.py](https://github.com/saarthdeshpande/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file5_fs2.gif)
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file1_tnb_creation.gif b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file1_tnb_creation.gif
new file mode 100644
index 0000000..eae8686
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file1_tnb_creation.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file1_tnb_creation.py b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file1_tnb_creation.py
new file mode 100644
index 0000000..80372ee
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file1_tnb_creation.py
@@ -0,0 +1,66 @@
+from manimlib.imports import *
+
+class tnb(ThreeDScene):
+ def construct(self):
+ self.set_camera_orientation(phi = 75*DEGREES, theta=45*DEGREES)
+
+ helix1 = ParametricFunction(
+ lambda t: np.array([
+ np.cos(TAU*t),
+ np.sin(TAU*t),
+ 0.4*t
+ ]), t_min = -2*np.pi/3, t_max = -1.638*np.pi/3, color = WHITE
+ )
+
+ helix2 = ParametricFunction(
+ lambda t: np.array([
+ np.cos(TAU*t),
+ np.sin(TAU*t),
+ 0.4*t
+ ]), t_min = -1.638*np.pi/3, t_max = -1.33*np.pi/3, color = WHITE
+ )
+
+ pointText = TextMobject(r'Consider an arbitrary point \\ on the given curve.').scale(0.8).shift(1.5*UP)
+ tgtText = TextMobject(r'Unit', ' tangent ', r'vector at \\ this point is given as:').scale(0.8).shift(1.5*UP)
+ tgtText.set_color_by_tex_to_color_map({
+ "tangent": YELLOW
+ })
+ normalText = TextMobject(r'Unit', ' normal ', r'vector at \\ this point is given as:').scale(0.8).shift(1.5*UP)
+ normalText.set_color_by_tex_to_color_map({
+ "normal": BLUE
+ })
+ planeText = TextMobject(r'$\overrightarrow{T}$ and $\overrightarrow{N}$ \\ prescribe a plane.').scale(0.8).shift(1.5*UP)
+ bnmText = TextMobject(r'The vector normal to this plane \\ is called the', ' binormal ', 'vector.').scale(0.8).shift(1.5*UP)
+ bnmText.set_color_by_tex_to_color_map({
+ "binormal": GREEN_E
+ })
+
+ dot1 = Dot(np.array([np.cos(-np.pi/3), np.sin(-np.pi/3), -0.4*np.pi/3]) + np.array([0,0.2,0]), radius = 0.16, color=RED)
+ tgt1 = Arrow((0,0,0), (-2,-0.55,0), color = YELLOW).shift(dot1.get_center() + np.array([0.18,0.04,0]))
+ nm1 = Arrow((0,0,0), (0.4,-2,0), color = BLUE).shift(dot1.get_center() + np.array([0,0.26,0]))
+ bnm1 = Arrow((0,0,0), (0,2,0), color=GREEN_E).shift(2.1*RIGHT+2*DOWN)
+ plane1 = Square(color = DARK_BROWN, fill_color = WHITE, fill_opacity=0.3).shift(dot1.get_center() + np.array([-0.4, -0.6, 0])).rotate(13*DEGREES).scale(1.2)
+ point1 = VGroup(*[dot1, tgt1, nm1, plane1]).scale(0.8).shift(np.array([1,4.86,0])).rotate(-15*DEGREES)
+
+
+
+ helix = VGroup(*[helix1, helix2])
+ self.play(FadeIn(helix))
+ self.play(ApplyMethod(helix.scale, 4))
+ self.add_fixed_in_frame_mobjects(pointText)
+ self.play(FadeIn(dot1), FadeIn(pointText))
+ self.wait(2)
+ self.add_fixed_in_frame_mobjects(tgtText)
+ self.play(Write(tgt1), ReplacementTransform(pointText, tgtText))
+ self.wait(2)
+ self.add_fixed_in_frame_mobjects(normalText)
+ self.play(Write(nm1), ReplacementTransform(tgtText, normalText))
+ self.wait(2)
+ self.add_fixed_in_frame_mobjects(planeText)
+ self.play(FadeIn(plane1), ReplacementTransform(normalText, planeText))
+ self.wait(2)
+ self.add_fixed_in_frame_mobjects(bnmText)
+ self.add_fixed_in_frame_mobjects(bnm1)
+ self.play(ReplacementTransform(planeText, bnmText), Write(bnm1))
+ self.wait(2)
+ self.play(FadeOut(VGroup(*[helix, bnm1, bnmText, dot1, tgt1, nm1, plane1])))
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file2_tnb_basic.gif b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file2_tnb_basic.gif
new file mode 100644
index 0000000..67aaea2
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file2_tnb_basic.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file2_tnb_basic.py b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file2_tnb_basic.py
new file mode 100644
index 0000000..c870210
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file2_tnb_basic.py
@@ -0,0 +1,36 @@
+from manimlib.imports import *
+
+class tnb(ThreeDScene):
+ def construct(self):
+ t = TextMobject(r'T', color = YELLOW)
+ n = TextMobject(r'N', color = BLUE).next_to(t, RIGHT, buff=0)
+ b = TextMobject(r'B', color = GREEN_E).next_to(n, RIGHT, buff=0)
+ frame = TextMobject(r'Frame').next_to(b, RIGHT, buff=0.2)
+ f1 = TextMobject(r'$\overrightarrow{B}$ ', color = GREEN_E)
+ f2 = TextMobject(r' = $\overrightarrow{T}$', color = YELLOW).next_to(f1, RIGHT, buff=0.2)
+ f3 = TextMobject(r'$\times\overrightarrow{N}$', color = BLUE).next_to(f2, RIGHT, buff=0.1)
+ formula = VGroup(*[f1, f2, f3]).move_to(ORIGIN).shift(3*UP)
+
+ # text = VGroup(*[t,n,b,frame]).move_to(ORIGIN).shift(3*UP)
+ curve = ParametricFunction(
+ lambda t: np.array([
+ np.sin(TAU*t),
+ np.cos(TAU*t),
+ 0
+ ])
+ ).scale(2.5)
+ dot = Dot(color = RED).scale(1.5).shift(1.05*LEFT)
+ tgt = Arrow(dot.get_center(), (-2, 2, 0), color = YELLOW).shift(0.3*DOWN + 0.09*RIGHT)
+ normal = Arrow(tgt.get_start(), (1, 1, 0), color = BLUE).shift(0.2*LEFT + 0.05*DOWN)
+ binormal = Arrow(dot.get_center() - np.array([0,0,0.3]), (tgt.get_start()[0], tgt.get_start()[1],2), color = GREEN)
+ square = Square(color = DARK_BROWN, fill_color = WHITE, fill_opacity=0.3).move_to(tgt.get_start()).rotate(27*DEGREES).shift(UP+0.4*RIGHT).scale(1.2)
+ group = VGroup(*[dot, tgt, normal, square, binormal]).shift(np.array([-1.24,-1,0]))
+
+ self.add_fixed_in_frame_mobjects(formula)
+ self.add(curve, group)
+ self.wait(1)
+ self.move_camera(phi = 75*DEGREES, theta=45*DEGREES, run_time = 2)
+ self.add_fixed_in_frame_mobjects(formula)
+ self.begin_ambient_camera_rotation(rate = 0.5)
+ self.wait(5)
+ self.play(FadeOut(VGroup(*[formula, curve, dot, tgt, normal, square, binormal])))
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file3_tnb_frame_manim.gif b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file3_tnb_frame_manim.gif
new file mode 100644
index 0000000..78e3aa3
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file3_tnb_frame_manim.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file3_tnb_frame_manim.py b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file3_tnb_frame_manim.py
new file mode 100644
index 0000000..091c1e2
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file3_tnb_frame_manim.py
@@ -0,0 +1,218 @@
+from manimlib.imports import *
+
+class tnb(ThreeDScene):
+ def construct(self):
+ self.set_camera_orientation(phi = 75*DEGREES, theta=45*DEGREES)
+
+ t = TextMobject(r'T', color = YELLOW)
+ n = TextMobject(r'N', color = BLUE).next_to(t, RIGHT, buff=0)
+ b = TextMobject(r'B', color = GREEN_E).next_to(n, RIGHT, buff=0)
+ frame = TextMobject(r'Frame').next_to(b, RIGHT, buff=0.2)
+
+ text = VGroup(*[t,n,b,frame]).move_to(ORIGIN).shift(3*UP)
+
+ c1 = TextMobject(r'$r(t) = \left\langle\cos{t}, \sin{t}, 0.4t\right\rangle\quad r\prime (t) =\left\langle -\sin{t}, \cos{t}, 0.4\right\rangle$').next_to(text, DOWN, buff = 0.1).scale(0.7)
+
+
+ helix1 = ParametricFunction(
+ lambda t: np.array([
+ np.cos(TAU*t),
+ np.sin(TAU*t),
+ 0.4*t
+ ]), t_min = -2*np.pi/3, t_max = -1.638*np.pi/3, color = WHITE
+ )
+
+ helix2 = ParametricFunction(
+ lambda t: np.array([
+ np.cos(TAU*t),
+ np.sin(TAU*t),
+ 0.4*t
+ ]), t_min = -1.638*np.pi/3, t_max = -1.33*np.pi/3, color = WHITE
+ )
+
+ helix3 = ParametricFunction(
+ lambda t: np.array([
+ np.cos(TAU*t),
+ np.sin(TAU*t),
+ 0.4*t
+ ]), t_min = -1.33*np.pi/3, t_max = -np.pi/3, color = WHITE
+ )
+
+ helix4 = ParametricFunction(
+ lambda t: np.array([
+ np.cos(TAU*t),
+ np.sin(TAU*t),
+ 0.4*t
+ ]), t_min = -np.pi/3, t_max = -1.3*np.pi/6, color = WHITE
+ )
+
+ helix5 = ParametricFunction(
+ lambda t: np.array([
+ np.cos(TAU*t),
+ np.sin(TAU*t),
+ 0.4*t
+ ]), t_min = -1.3*np.pi/6, t_max = 0, color = WHITE
+ )
+
+ helix_dot = Dot(radius = 0.16, color = RED)
+
+ t_tracker = ValueTracker(-2*np.pi/3)
+ t=t_tracker.get_value
+
+ # t_label = TexMobject(
+ # "t = ",color=WHITE
+ # ).next_to(helix1,DOWN, buff=0.2).scale(0.6)
+
+ cval1 = TextMobject(r'r(').next_to(c1, DOWN+16.5*LEFT, buff = 0.1).scale(0.7)
+
+ t_text = always_redraw(
+ lambda: DecimalNumber(
+ t(),
+ color=WHITE,
+ ).next_to(cval1, RIGHT, buff=0.05).scale(0.7)
+ ).scale(0.6)
+
+
+ cval2 = always_redraw(
+ lambda: TextMobject(r') = $\left\langle$').scale(0.7).next_to(t_text, RIGHT, buff = 0.05)
+ )
+
+ cos = always_redraw(
+ lambda: DecimalNumber(
+ np.cos(t()),
+ color=WHITE,
+ ).next_to(cval2, RIGHT, buff=0.1).scale(0.7)
+ ).scale(0.6)
+
+ sin = always_redraw(
+ lambda: DecimalNumber(
+ np.sin(t()),
+ color=WHITE,
+ ).next_to(cos, RIGHT, buff=0.1).scale(0.7)
+ ).scale(0.6)
+
+ zpart = always_redraw(
+ lambda: DecimalNumber(
+ 0.4* t(),
+ color=WHITE,
+ ).next_to(sin, RIGHT, buff=0.1).scale(0.7)
+ ).scale(0.6)
+
+ cvalend = always_redraw(
+ lambda: TextMobject(r' $\right\rangle$').next_to(zpart, RIGHT, buff = 0.2).scale(0.7)
+ ).scale(0.6)
+
+
+ valgroup = VGroup(*[cval1, cval2,cos,sin,zpart, cvalend])
+
+ rp1 = always_redraw(
+ lambda: TextMobject(r'$r\prime ($').scale(0.7).next_to(cvalend, RIGHT, buff = 0.6)
+ )
+
+ t_text2 = always_redraw(
+ lambda: DecimalNumber(
+ t(),
+ color=WHITE,
+ ).next_to(rp1, RIGHT, buff=0.05).scale(0.7)
+ ).scale(0.6)
+
+ rp2 = always_redraw(
+ lambda: TextMobject(r') = $\left\langle$').scale(0.7).next_to(t_text2, RIGHT, buff = 0.05)
+ )
+
+ rps = always_redraw(
+ lambda: DecimalNumber(
+ -np.sin(t()),
+ color=WHITE,
+ ).next_to(rp2, RIGHT, buff=0.1).scale(0.7)
+ ).scale(0.6)
+
+
+ rpc = always_redraw(
+ lambda: DecimalNumber(
+ np.cos(t()),
+ color=WHITE,
+ ).next_to(rps, RIGHT, buff=0.1).scale(0.7)
+ ).scale(0.6)
+
+
+ const = always_redraw(
+ lambda: TextMobject(r'0.4 $\right\rangle$').next_to(rpc, RIGHT, buff = 0.2).scale(0.7)
+ ).scale(0.6).shift(0.1*DOWN)
+
+ val2group = VGroup(*[rp1, rp2, rps, rpc, const])
+
+ #group = VGroup(t_text, t_text2).scale(1.5).move_to(ORIGIN).shift(3.7*DOWN)
+
+
+ dot0 = Dot(np.array([np.cos(-2*np.pi/3), np.sin(-2*np.pi/3), -0.8*np.pi/3]), radius = 0.16, color=RED).shift(np.array([4.65,0,-0.8]))
+ tgt0 = Arrow((0,0,0), (1,2,0), color = YELLOW).shift(dot0.get_center() - np.array([0.04,0.2,0]))
+ nm0 = Arrow((0,0,0), (-2,1,0), color = BLUE).shift(dot0.get_center() + np.array([0.3,0,0]))
+ bnm0 = Arrow((0,0,0), (0,2,0), color = GREEN_E).shift(6.1*LEFT + 3*DOWN)
+ plane0 = Square(color = DARK_BROWN, fill_color = WHITE, fill_opacity=0.3).shift(dot0.get_center() + np.array([-0.35, 0.85, 0])).scale(1.2).rotate(65*DEGREES)
+ point0 = VGroup(*[dot0, tgt0, nm0, bnm0, plane0]).scale(0.8).shift(np.array([1,0,0]))
+
+ dot1 = Dot(np.array([np.cos(-np.pi/3), np.sin(-np.pi/3), -0.4*np.pi/3]) + np.array([0,0.2,0]), radius = 0.16, color=RED)
+ tgt1 = Arrow((0,0,0), (-2,-0.55,0), color = YELLOW).shift(dot1.get_center() + np.array([0.18,0.04,0]))
+ nm1 = Arrow((0,0,0), (0.4,-2,0), color = BLUE).shift(dot1.get_center() + np.array([0,0.26,0]))
+ bnm1 = Arrow((0,0,0), (0,2,0), color=GREEN_E).shift(3.68*RIGHT+2.48*DOWN)
+ plane1 = Square(color = DARK_BROWN, fill_color = WHITE, fill_opacity=0.3).shift(dot1.get_center() + np.array([-0.4, -0.6, 0])).rotate(13*DEGREES).scale(1.2)
+ point1 = VGroup(*[dot1, tgt1, nm1, plane1]).scale(0.8).shift(np.array([1,6.25,0]))
+
+ dot2 = Dot(np.array([np.cos(-np.pi/6), np.sin(-np.pi/6), -0.2*np.pi/3]) - np.array([1.9,0,0]), radius=0.16,color=RED)
+ tgt2 = Arrow((0,0,0), (1,-2,0), color = YELLOW).shift(dot2.get_center() + np.array([-0.2,0.2,0]))
+ nm2 = Arrow((0,0,0), (2,1,0), color = BLUE).shift(dot2.get_center() + np.array([-0.2,-0.06,0]))
+ bnm2 = Arrow((0,0,0), (0,2,0), color=GREEN_E).shift(0.4*RIGHT + 0.16*DOWN)
+ plane2 = Square(color = DARK_BROWN, fill_color = WHITE, fill_opacity=0.3).shift(dot2.get_center() + np.array([0.92, -0.5, 0])).rotate(23*DEGREES).scale(1.2)
+ point2 = VGroup(*[dot2, tgt2, nm2, bnm2, plane2])
+
+ helix = VGroup(*[helix1, helix2, helix3, helix4, helix5])
+ self.add_fixed_in_frame_mobjects(text, c1)
+ self.play(FadeIn(helix), FadeIn(text), FadeIn(c1))
+ self.play(ApplyMethod(helix.scale, 4))
+ self.add_fixed_in_frame_mobjects(bnm0, valgroup, val2group, t_text, t_text2)
+ self.play(FadeIn(point0), FadeIn(t_text), FadeIn(t_text2), FadeIn(valgroup), FadeIn(val2group))
+ self.play(ApplyMethod(point0.set_color, GRAY, opacity = 0.1, run_time = 0.5), MoveAlongPath(helix_dot, helix1, run_time=5), t_tracker.set_value,-1.638*np.pi/3, rate_func=linear, run_time=5)
+
+ self.add_fixed_in_frame_mobjects(bnm1)
+ self.play(FadeIn(point1))
+ self.play(ApplyMethod(point1.set_color, GRAY, opacity = 0.1, run_time = 0.5), ApplyMethod(bnm1.set_color, GRAY, opacity = 0.1, run_time = 0.5), MoveAlongPath(helix_dot, helix2, run_time = 5), t_tracker.set_value,-1.33*np.pi/3, rate_func=linear, run_time=5)
+
+ self.add_fixed_in_frame_mobjects(bnm2)
+ self.play(FadeIn(point2))
+ self.play(ApplyMethod(point2.set_color, GRAY, opacity = 0.1, run_time = 0.5), MoveAlongPath(helix_dot, helix3, run_time=5), t_tracker.set_value,-np.pi/3, rate_func=linear, run_time=5)
+
+ dot3 = Dot(np.array([np.cos(-np.pi/3), np.sin(-np.pi/3), -0.4*np.pi/3]) + np.array([3.3,-0.25,0]), radius = 0.16, color=RED)
+ tgt3 = Arrow((0,0,0), (0,2,0), color = YELLOW).shift(helix_dot.get_center() - np.array([-0.05,0.2,0]))
+ nm3 = Arrow((0,0,0), (-2,0,0), color = BLUE).shift(helix_dot.get_center() + np.array([0.25,0,0]))
+ bnm3 = Arrow((0,0,0), (0,2,0), color = GREEN_E).shift(3.87*LEFT + 1.24*DOWN)
+ plane3 = Square(color = DARK_BROWN, fill_color = WHITE, fill_opacity=0.3).shift(helix_dot.get_center() + np.array([-0.5, 0.62, 0]))
+ point3 = VGroup(*[dot3, tgt3, nm3, bnm3, plane3]).shift(np.array([0,0,0]))
+
+ dot4 = Dot(np.array([np.cos(-np.pi/12), np.sin(-np.pi/12), -0.1*np.pi/3]) + np.array([-3.4,3.4,0]), radius = 0.16, color=RED)
+ tgt4 = Arrow((0,0,0), (-2,-0.85,0), color = YELLOW).shift(dot4.get_center() - np.array([-0.05,0,0]))
+ nm4 = Arrow((0,0,0), (0.8,-2,0), color = BLUE).shift(dot4.get_center() + np.array([-0.1,0.25,0]))
+ bnm4 = Arrow((0,0,0), (0,2,0), color = GREEN_E).shift(4.03*RIGHT + 0.5*DOWN)
+ plane4 = Square(color = DARK_BROWN, fill_color = WHITE, fill_opacity=0.3).shift(dot4.get_center() + np.array([-0.4,-1,0])).rotate(22*DEGREES).scale(1.2)
+ point4 = VGroup(*[dot4, tgt4, nm4, bnm4, plane4])
+
+ dot5 = Dot((1,0,0) + np.array([2.3,-1,1]))
+ tgt5 = Arrow((0,0,0), (0,2,0), color = YELLOW).shift(dot5.get_center() - np.array([-0.05,0.2,0]))
+ nm5 = Arrow((0,0,0), (-2,0,0), color = BLUE).shift(dot5.get_center() + np.array([0.25,0,0]))
+ bnm5 = Arrow((0,0,0), (0,2,0), color = GREEN_E).shift(3.34*LEFT+0.3*UP)
+ plane5 = Square(color = DARK_BROWN, fill_color = WHITE, fill_opacity=0.3).shift(dot5.get_center() + np.array([-0.5,0.5,0]))
+ point5 = VGroup(*[tgt5, nm5, bnm5, plane5])
+
+ self.add_fixed_in_frame_mobjects(bnm3)
+ self.play(FadeIn(point3))
+ self.play(ApplyMethod(point3.set_color, GRAY, opacity = 0.1, run_time = 0.5), MoveAlongPath(helix_dot, helix4, run_time=5), t_tracker.set_value,-1.3*np.pi/6, rate_func=linear, run_time=5)
+
+ self.add_fixed_in_frame_mobjects(bnm4)
+ self.play(FadeIn(point4))
+ self.play(ApplyMethod(point4.set_color, GRAY, opacity = 0.1, run_time = 0.5), MoveAlongPath(helix_dot, helix5, run_time=5), t_tracker.set_value,0, rate_func=linear, run_time=5)
+
+ self.add_fixed_in_frame_mobjects(bnm5)
+ self.play(FadeIn(point5))
+ self.wait(2)
+
+ self.play(FadeOut(VGroup(*[valgroup, val2group, t_text, t_text2, c1, text, helix, bnm1, point0, point1, point2, point3, point4, point5, helix_dot])))
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file4_fs1.py b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file4_fs1.py
new file mode 100644
index 0000000..f3f5a9c
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file4_fs1.py
@@ -0,0 +1,91 @@
+from manimlib.imports import *
+class fs1(GraphScene):
+ CONFIG = {
+ "x_min": -2,
+ "x_max": 2,
+ "y_min": -6,
+ "y_max": 6,
+ "graph_origin": ORIGIN
+ }
+ def construct(self):
+
+ text = TextMobject(r'$\frac{dT}{ds} = \kappa N$ \\ $\frac{dT}{ds}$ gives the direction of N, \\ while $\kappa$ gives its magnitude.').scale(0.7).shift(3*UP + 3*LEFT)
+
+ self.setup_axes()
+ def curve_(x):
+ return x**3 - 2*x
+
+ def nm(x):
+ return abs(6 * x / ((9*(x**4) - 6*(x**2) + 5)**1.5))
+
+ figure = self.get_graph(curve_)
+
+
+ dot = Dot().rotate(PI/2)
+ alpha = ValueTracker(0)
+ t2_ = ValueTracker(-2)
+ t2 = t2_.get_value
+ t = alpha.get_value
+ vector_x = self.get_tangent_vector(t(),figure,scale=2)
+ vector_y = self.get_normal_vector(t(),figure,scale=2)
+
+ kappa = TextMobject(r'$\kappa = $').scale(0.7).shift(3*DOWN + 3*RIGHT)
+
+ t_text = always_redraw(
+ lambda: DecimalNumber(
+ nm(t2()),
+ color=WHITE,
+ ).scale(0.7).next_to(kappa)
+ ).scale(0.6)
+
+ self.play(
+ ShowCreation(figure),
+ GrowFromCenter(dot),
+ GrowArrow(vector_x),
+ GrowArrow(vector_y)
+ )
+ vector_x.add_updater(
+ lambda m: m.become(
+ self.get_tangent_vector(t(),figure,scale=2)
+ )
+ )
+ vector_y.add_updater(
+ lambda m: m.become(
+ self.get_normal_vector(t(),figure,scale=2)
+ )
+ )
+ dot.add_updater(lambda m: m.move_to(vector_x.get_start()))
+ circle = Circle(radius = 2, color = GREEN_SCREEN). shift(2.63*RIGHT + 2.8*UP)
+ dot2 = Dot(np.array([2, curve_(2), 0]), color = WHITE).shift(2*DOWN + 2.5*RIGHT)
+
+ self.add(vector_x, vector_y,dot, t_text, kappa, text)
+ self.play(t2_.set_value, 2, alpha.set_value, 1, run_time=18, rate_func=smooth)
+ self.play(FadeIn(dot2), FadeIn(circle))
+ self.wait(2)
+ self.play(FadeOut(VGroup(*[self.axes, dot2, figure, circle, text, kappa, t_text])))
+
+
+ def get_tangent_vector(self, proportion, curve, dx=0.001, scale=0.5):
+ coord_i = curve.point_from_proportion(proportion)
+ coord_f = curve.point_from_proportion(proportion + dx)
+ reference_line = Line(coord_i,coord_f)
+ unit_vector = reference_line.get_unit_vector() * 0.7
+ vector = Arrow(coord_i , coord_i + unit_vector, color = YELLOW, buff=0)
+ return vector
+
+ def get_normal_vector(self, proportion, curve, dx=0.001, scale=1):
+ t = proportion.copy()/6
+ coord_i = curve.point_from_proportion(proportion)
+ coord_f = curve.point_from_proportion(proportion + dx)
+ length = 6 * t / ((9*(t**4) - 6*(t**2) + 5)**1.5)
+ if coord_i[0] <= 0 and coord_i[0] > -0.5:
+ reference_line = Line(coord_i,coord_f).rotate(PI/2).set_width(0).scale(2)
+ elif coord_i[0] > 0 and (coord_i[0] < 0.5 or coord_i[0] > 2.7):
+ reference_line = Line(coord_i,coord_f).rotate(PI/2).set_width(0).scale(2)
+ elif coord_i[0] > 0:
+ reference_line = Line(coord_i,coord_f).rotate(PI/2).set_width(length).scale(2)
+ else:
+ reference_line = Line(coord_i,coord_f).rotate(-PI/2).set_width(length).scale(2)
+ unit_vector = reference_line.get_vector() * scale
+ vector = Arrow(coord_i , coord_i + unit_vector, color = RED_C, buff=0)
+ return vector
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file5_torsion_intuition.py b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file5_torsion_intuition.py
new file mode 100644
index 0000000..31b9a85
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file5_torsion_intuition.py
@@ -0,0 +1,119 @@
+from manimlib.imports import *
+
+class t(SpecialThreeDScene):
+ CONFIG = {
+ "axes_config": {
+ "x_min": -5,
+ "x_max": 5,
+ "y_min": -5,
+ "y_max": 5,
+ "z_min": -4,
+ "z_max": 4,
+ "x_axis_config": {
+ "tick_frequency": 100,
+ },
+ "y_axis_config": {
+ "tick_frequency": 100,
+ },
+ "z_axis_config": {
+ "tick_frequency": 100,
+ },
+ "num_axis_pieces": 1,
+ }
+ }
+ def construct(self):
+
+ text = TextMobject(r'Torsion can be intuitively \\ thought of as the measure \\ of "twisting" of a curve.').scale(0.7).shift(2.5*UP + 4.2*LEFT)
+
+
+ dot = Dot().rotate(PI/2)
+ f1 = ParametricFunction(
+ lambda t: np.array([
+ 2*np.sin(TAU*t),
+ 2*np.cos(TAU*t),
+ 2*t
+ ]), t_min = -2, t_max = 2, color = BLUE
+ ).scale(0.5)
+ d1 = Dot(color = RED).next_to(f1.get_center(), 2*DOWN + LEFT, buff = 0).shift(1.2*UP + 2.4*RIGHT)
+ t1 = self.get_torsion(2, 0.174)
+ t1 = "{:.2f}".format(t1)
+ t1 = TextMobject(fr'At the given point, $\tau = {t1}$').shift(3.5*DOWN).scale(0.7)
+
+ f2 = ParametricFunction(
+ lambda t: np.array([
+ 3*np.sin(TAU*t),
+ 3*np.cos(TAU*t),
+ 2*t
+ ]), t_min = -2, t_max = 2, color = BLUE
+ ).scale(0.5)
+ d2 = Dot(color = RED).next_to(f2.get_center(), 2*DOWN + LEFT, buff = 0).shift(1.2*UP + 2.95*RIGHT)
+ t2 = self.get_torsion(3, 0.1765)
+ t2 = "{:.2f}".format(t2)
+ t2 = TextMobject(fr'At the given point, $\tau = {t2}$').shift(3.5*DOWN).scale(0.7)
+
+ f3 = ParametricFunction(
+ lambda t: np.array([
+ 4*np.sin(TAU*t),
+ 4*np.cos(TAU*t),
+ 2*t
+ ]), t_min = -2, t_max = 2, color = BLUE
+ ).scale(0.5)
+ d3 = Dot(color = RED).next_to(f3.get_center(), 2*DOWN + LEFT, buff = 0).shift(1.2*UP + 3.45*RIGHT)
+ t3 = self.get_torsion(4, 0.179)
+ t3 = "{:.2f}".format(t3)
+ t3 = TextMobject(fr'At the given point, $\tau = {t3}$').shift(3.5*DOWN).scale(0.7)
+
+ f4 = ParametricFunction(
+ lambda t: np.array([
+ 1.5*np.sin(TAU*t),
+ 1.5*np.cos(TAU*t),
+ 2*t
+ ]), t_min = -2, t_max = 2, color = BLUE
+ ).scale(0.5)
+ d4 = Dot(color = RED).next_to(f4.get_center(), 2*DOWN + LEFT, buff = 0).shift(1.215*UP + 2.128*RIGHT)
+ t4 = self.get_torsion(1.5, 0.173)
+ t4 = "{:.2f}".format(t4)
+ t4 = TextMobject(fr'At the given point, $\tau = {t4}$').shift(3.5*DOWN).scale(0.7)
+
+ f5 = ParametricFunction(
+ lambda t: np.array([
+ np.sin(TAU*t),
+ np.cos(TAU*t),
+ 2*t
+ ]), t_min = -2, t_max = 2, color = BLUE
+ ).scale(0.5)
+
+ d5 = Dot(color = RED).next_to(f5.get_center(), 2*DOWN + LEFT, buff = 0).shift(1.3*UP + 1.858*RIGHT)
+ t5 = self.get_torsion(1, 0.17)
+ t5 = "{:.2f}".format(t5)
+ t5 = TextMobject(fr'At the given point, $\tau = {t5}$').shift(3.5*DOWN).scale(0.7)
+
+ axes = ThreeDAxes(**self.axes_config)
+ self.set_camera_orientation(phi = 60*DEGREES, theta=45*DEGREES)
+ self.add_fixed_in_frame_mobjects(t1, text)
+ self.play(FadeIn(VGroup(*[f1, d1, t1, axes, text])))
+ self.wait(2)
+ self.add_fixed_in_frame_mobjects(t2)
+ self.play(ReplacementTransform(d1, d2), ReplacementTransform(f1, f2), ReplacementTransform(t1, t2))
+ self.wait(2)
+ self.add_fixed_in_frame_mobjects(t3)
+ self.play(ReplacementTransform(d2, d3), ReplacementTransform(f2, f3), ReplacementTransform(t2, t3))
+ self.wait(2)
+ self.add_fixed_in_frame_mobjects(t4)
+ self.play(ReplacementTransform(d3, d4), ReplacementTransform(f3, f4), ReplacementTransform(t3, t4))
+ self.wait(2)
+ self.add_fixed_in_frame_mobjects(t5)
+ self.play(ReplacementTransform(d4, d5), ReplacementTransform(f4, f5), ReplacementTransform(t4, t5))
+ self.wait(2)
+ self.play(FadeOut(VGroup(*[d5, f5, t5, text, axes])))
+
+ def get_torsion(self, a, t):
+ rprime = np.array([a*np.cos(t), -a*np.sin(t), 2])
+ T = rprime / np.sqrt(np.dot(rprime, rprime))
+ rpp = np.array([-a*np.sin(t), -a*np.cos(t), 0])
+ n = rpp / np.dot(rpp, rpp)
+ b = np.cross(T, n)
+ dbdt = np.array([-2*np.sin(t), -2*np.cos(t), 0])
+ tor = np.dot(dbdt, n)
+
+ return tor
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file6_fs2.py b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file6_fs2.py
new file mode 100644
index 0000000..0c74685
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file6_fs2.py
@@ -0,0 +1,90 @@
+from manimlib.imports import *
+
+class fs2(SpecialThreeDScene):
+ CONFIG = {
+ "x_min": -2,
+ "x_max": 2,
+ "y_min": -6,
+ "y_max": 6,
+ "graph_origin": ORIGIN
+ }
+ def construct(self):
+ axes = ThreeDAxes()
+ # text = TextMobject(r'$\frac{dB}{ds} = -\tau N$ \\ $\frac{dB}{ds}$ gives the direction of N, \\ while $\tau$ gives its magnitude.').scale(0.7).shift(3*UP + 3*LEFT)
+ self.set_camera_orientation(phi = 75*DEGREES, theta=135*DEGREES)
+ # self.move_camera(distance=0)
+
+ # rprime = np.array([2*np.cos(t), -np.sin(t) - (2*np.sin(2*t)), 0])
+ # t = rprime / np.sqrt(np.dot(rprime, rprime))
+ # rpp = np.array([-2*np.sin(t), -np.cos(t) - (4*np.cos(2*t)), 0])
+ # n = rpp / np.dot(rpp, rpp)
+ # b = np.cross(rprime, rpp)
+ text = TextMobject(r'$\frac{dB}{ds}$', r'$= -\tau$', r'$N$').shift(2*UP + 4*LEFT)
+ text.set_color_by_tex_to_color_map({
+ r'$\frac{dB}{ds}$': YELLOW,
+ r'$N$': RED_C
+ })
+
+ dot = Dot().rotate(PI/2)
+ alpha = ValueTracker(0)
+ t = alpha.get_value
+ figure = ParametricFunction(
+ lambda t: np.array([
+ np.sinh(t),
+ np.cosh(t),
+ 2*t
+ ]), t_min = -3, t_max = 3, color=BLUE
+ ).scale(0.5).move_to(ORIGIN)
+ vector_x = self.get_tangent_vector(t()%1, figure,scale=2)
+ vector_y = self.get_normal_vector(t(),figure,scale=2)
+ vector_x.add_updater(
+ lambda m: m.become(
+ self.get_tangent_vector(t()%1,figure,scale=2)
+ )
+ )
+ vector_y.add_updater(
+ lambda m: m.become(
+ self.get_normal_vector(t(),figure,scale=2)
+ )
+ )
+ dot.add_updater(lambda m: m.move_to(vector_y.get_start()))
+
+
+
+ self.add_fixed_in_frame_mobjects(text)
+ self.play(FadeIn(figure), FadeIn(axes), FadeIn(text))
+ self.begin_ambient_camera_rotation(rate = 0.1)
+ self.wait(1)
+ self.add(vector_x, vector_y,dot)
+ self.play(alpha.increment_value, 0.999, run_time=20, rate_func=rush_from)
+ self.wait(1)
+ self.remove(figure, vector_x, vector_y,dot)
+ self.play(FadeOut(figure), FadeOut(axes), FadeOut(text))
+
+ def get_tangent_vector(self, proportion, curve, dx=0.001, scale=1):
+ t = proportion.copy()
+ coord_i = curve.point_from_proportion(proportion)
+ rprime = np.array([np.cosh(t), np.sinh(t), 2])
+ T = rprime / np.sqrt(np.dot(rprime, rprime))
+ rpp = np.array([np.sinh(t), np.cosh(t), 0])
+ n = rpp / np.dot(rpp, rpp)
+ # b = (np.cross(T, n)[0] - 0.5, np.cross(T, n)[1], coord_i[2] + 1)
+ b = np.cross(T, n)
+ # coord_f = curve.point_from_proportion(proportion + dx)
+ coord_f = b
+ reference_line = Line(coord_i,coord_f)
+ unit_vector = reference_line.get_unit_vector() * 1
+ vector = Arrow(coord_i , coord_i + unit_vector, color = YELLOW, buff=0)
+ return vector
+
+ def get_normal_vector(self, proportion, curve, dx=0.001, scale=1):
+ coord_i = curve.point_from_proportion(proportion)
+ coord_f = curve.point_from_proportion(proportion + dx)
+ t = proportion.copy()/7
+ rpp = np.array([np.sinh(t), np.cosh(t), 0])
+ length = np.sqrt(np.dot(rpp, rpp))
+ length = 1/(1 + np.exp(-length))
+ reference_line = Line(coord_i,coord_f).rotate(PI/2).set_width(length).scale(2)
+ unit_vector = reference_line.get_vector() * 0.7
+ vector = Arrow(coord_i, coord_i + unit_vector, color = RED_C, buff=0)
+ return vector
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file7_fs3.py b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file7_fs3.py
new file mode 100644
index 0000000..698ca74
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/tnb-frame-and-serret-frenet-formulae/file7_fs3.py
@@ -0,0 +1,194 @@
+from manimlib.imports import *
+
+class f(SpecialThreeDScene):
+ CONFIG = {
+ "axes_config": {
+ "x_min": -5,
+ "x_max": 5,
+ "y_min": -5,
+ "y_max": 5,
+ "z_min": -4,
+ "z_max": 4,
+ "x_axis_config": {
+ "tick_frequency": 100,
+ },
+ "y_axis_config": {
+ "tick_frequency": 100,
+ },
+ "z_axis_config": {
+ "tick_frequency": 100,
+ },
+ "num_axis_pieces": 1,
+ }
+ }
+ def construct(self):
+ axes = ThreeDAxes(**self.axes_config)
+ text = TextMobject(r'$r(t) = \left\langle\sinh{t}, \cosh{t}, 2t\right\rangle$').scale(0.7).shift(3*UP + 3*LEFT)
+ self.set_camera_orientation(phi = 75*DEGREES, theta=225*DEGREES)
+
+
+
+ figure = ParametricFunction(
+ lambda t: np.array([
+ np.sinh(t),
+ np.cosh(t),
+ 2*t
+ ]), t_min = -3, t_max = 3, color=ORANGE
+ ).scale(0.5).move_to(ORIGIN)
+
+ dot = Dot(color=RED)
+ alpha = ValueTracker(0)
+ t = alpha.get_value
+
+ vector_x = self.get_binormal_vector(t()%1, figure,scale=2)
+ vector_y = self.get_normal_vector(t(),figure,scale=2)
+ vector_z = self.get_tangent_vector(t(), figure, scale=2)
+
+ vector_x.add_updater(
+ lambda m: m.become(
+ self.get_binormal_vector(t()%1,figure,scale=2)
+ )
+ )
+ vector_y.add_updater(
+ lambda m: m.become(
+ self.get_normal_vector(t(),figure,scale=2)
+ )
+ )
+ vector_z.add_updater(
+ lambda m: m.become(
+ self.get_tangent_vector(t(),figure,scale=2)
+ )
+ )
+ dot.add_updater(
+ lambda m: m.move_to(vector_x.get_start())
+ )
+ def curvature(t):
+ r = np.array([np.sinh(t), np.cosh(t), 2*t])
+ rp = np.array([np.cosh(t), np.sinh(t), 2])
+ rpp = np.array([np.sinh(t), np.cosh(t), 0])
+ cp = np.cross(rp, rpp)
+ k = cp / (np.dot(rp, rp)**1.5)
+ return abs(k[0])
+
+ def torsion(t):
+ r = np.array([np.sinh(t), np.cosh(t), 2*t])
+ rp = np.array([np.cosh(t), np.sinh(t), 2])
+ rpp = np.array([np.sinh(t), np.cosh(t), 0])
+ n = rpp / np.dot(rpp, rpp)
+ dbdt = np.array([2*np.sinh(t), 2*np.cosh(t), 0])
+ tor = np.dot(dbdt, n)
+ return tor
+
+
+
+ k = curvature(0.3)
+ k = "{:.2f}".format(k)
+ tor = torsion(0.3)
+ tor = "{:.2f}".format(tor)
+ kt1 = TextMobject(rf'At the given point, \\ $\kappa =$ {k} \\').scale(0.7).shift(3*UP + 4*RIGHT)
+ kt2 = TextMobject('$\implies \kappa$',r'$T$',r' is scaled as:').scale(0.7).next_to(kt1, DOWN, buff=0.1)
+ kt2.set_color_by_tex_to_color_map({
+ '$T$': YELLOW
+ })
+ tbt1 = TextMobject(rf'At the given point, \\ $\tau =$ {tor} \\').scale(0.7).shift(3*UP + 4*RIGHT)
+ tbt2 = TextMobject(r'$\implies \tau$',r'$B$',r' is scaled as:').scale(0.7).next_to(tbt1, DOWN, buff=0.1)
+ tbt2.set_color_by_tex_to_color_map({
+ '$B$': GREEN_E
+ })
+ ft = TextMobject(r'$\frac{dN}{ds}$',r'$ = -\kappa$',r'$T$', r'$ + \tau$',r'$B$ \\', r'and is given as:').scale(0.7).shift(3*UP + 4*RIGHT)
+ ft.set_color_by_tex_to_color_map({
+ r'$\frac{dN}{ds}$': GREEN_SCREEN,
+ '$T$': YELLOW,
+ r'$B$ \\': GREEN_E
+ })
+
+ self.add_fixed_in_frame_mobjects(text)
+ self.play(FadeIn(figure), FadeIn(axes), FadeIn(text))
+ # self.begin_ambient_camera_rotation(rate = 0.13)
+ self.wait(1)
+ self.add(vector_x, vector_y,vector_z,dot)
+ self.play(alpha.increment_value, 0.3, run_time=10, rate_func=rush_from)
+ self.wait(1)
+ # self.stop_ambient_camera_rotation()
+ # self.move_camera(phi = 75*DEGREES, theta=225*DEGREES)
+ square = Rectangle(width=3.2, fill_color=WHITE, fill_opacity=0.3, color=RED_C).rotate(40*DEGREES).shift(0.8*DOWN+1.2*RIGHT)
+ mat = [[0.7, 0.3], [1.0, -0.7]]
+ square = square.apply_matrix(mat).rotate(17*DEGREES).shift(2.1*DOWN+RIGHT)
+ tl, nl, bl = TextMobject(r'$T$', color=YELLOW).shift(2.8*RIGHT+0.5*DOWN), TextMobject(r'$N$', color=BLUE).shift(RIGHT), TextMobject(r'$B$', color=GREEN_E).shift(0.6*LEFT+0.5*DOWN)
+ self.add_fixed_in_frame_mobjects(tl, nl, bl)
+ self.play(FadeIn(VGroup(*[tl, nl, bl])))
+ self.wait(3)
+ self.add_fixed_in_frame_mobjects(square)
+ self.play(FadeIn(square), FadeOut(VGroup(*[tl, nl, bl])))
+ self.wait(2)
+ self.add_fixed_in_frame_mobjects(kt1)
+ self.play(FadeIn(kt1))
+ self.wait(2)
+ self.add_fixed_in_frame_mobjects(kt2)
+ self.play(FadeIn(kt2))
+ self.wait(2)
+ kt = self.get_tangent_vector(0.3, figure, scale = -4*float(k))
+ tb = self.get_binormal_vector(0.3, figure, scale = 2*float(tor))
+ self.play(
+ ReplacementTransform(vector_z, kt)
+ )
+ self.wait(3)
+ self.add_fixed_in_frame_mobjects(tbt1)
+ self.play(FadeOut(VGroup(*[kt1, kt2])), FadeIn(tbt1))
+ self.wait(2)
+ self.add_fixed_in_frame_mobjects(tbt2)
+ self.play(FadeIn(tbt2))
+ self.wait(2)
+ self.play(
+ ReplacementTransform(vector_x, tb)
+ )
+ self.wait(2)
+ self.add_fixed_in_frame_mobjects(ft)
+ self.play(FadeOut(VGroup(*[tbt1, tbt2])), FadeIn(ft))
+ self.wait(2)
+ dnds = Arrow(dot.get_center() + np.array([-0.1,-0.25,0]), np.array([-4,-1,2]), color=GREEN_SCREEN)
+ dndsl = TextMobject(r'$\frac{dN}{ds}$', color=GREEN_SCREEN).shift(2.5*LEFT + 1.2*UP)
+ self.add_fixed_in_frame_mobjects(dndsl)
+ self.play(FadeIn(dnds), FadeIn(dndsl))
+ self.wait(5)
+ self.play(FadeOut(VGroup(*[square, dot,vector_y, dnds, dndsl, text, ft, tb, kt])))
+ self.play(FadeOut(figure), FadeOut(axes))
+
+
+ def get_binormal_vector(self, proportion, curve, dx=0.001, scale=1):
+ t = proportion
+ coord_i = curve.point_from_proportion(proportion)
+ rprime = np.array([np.cosh(t), np.sinh(t), 2])
+ T = rprime / np.sqrt(np.dot(rprime, rprime))
+ rpp = np.array([np.sinh(t), np.cosh(t), 0])
+ n = rpp / np.dot(rpp, rpp)
+ # b = (np.cross(T, n)[0] - 0.5, np.cross(T, n)[1], coord_i[2] + 1)
+ b = np.cross(T, n)
+ # coord_f = curve.point_from_proportion(proportion + dx)
+ coord_f = b
+ reference_line = Line(coord_i,coord_f)
+ unit_vector = reference_line.get_unit_vector() * scale
+ vector = Arrow(coord_i , coord_i + unit_vector, color = GREEN_E, buff=0)
+ return vector
+
+ def get_normal_vector(self, proportion, curve, dx=0.001, scale=1):
+ coord_i = curve.point_from_proportion(proportion)
+ coord_f = curve.point_from_proportion(proportion + dx)
+ t = proportion.copy()/7
+ rpp = np.array([np.sinh(t), np.cosh(t), 0])
+ length = np.sqrt(np.dot(rpp, rpp))
+ length = 1/(1 + np.exp(-length))
+ reference_line = Line(coord_i,coord_f).rotate(PI/2).set_width(length).scale(2)
+ unit_vector = reference_line.get_unit_vector() * scale
+ vector = Arrow(coord_i, coord_i + unit_vector, color = BLUE, buff=0)
+ return vector
+
+ def get_tangent_vector(self, proportion, curve, dx=0.001, scale=1):
+ coord_i = curve.point_from_proportion(proportion)
+ coord_f = curve.point_from_proportion(proportion + dx)
+ reference_line = Line(coord_i,coord_f).scale(2)
+ if scale < 0:
+ reference_line = Line(coord_i,coord_f).scale(2).rotate(360*DEGREES)
+ unit_vector = reference_line.get_unit_vector() * scale
+ vector = Arrow(coord_i, coord_i + unit_vector, color = YELLOW, buff=0)
+ return vector
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/velocity-and-differentiability/README.md b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/velocity-and-differentiability/README.md
new file mode 100644
index 0000000..02678fd
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/velocity-and-differentiability/README.md
@@ -0,0 +1,2 @@
+**file3_tangent_space_curve.py** <br>
+![file3_tangent_space_curve.py](https://github.com/saarthdeshpande/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/velocity-and-differentiability/file3_tangent_space_curve.gif)
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/velocity-and-differentiability/file1_smooth_curves.gif b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/velocity-and-differentiability/file1_smooth_curves.gif
new file mode 100644
index 0000000..5801796
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/velocity-and-differentiability/file1_smooth_curves.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/velocity-and-differentiability/file2_non_differentiable.py b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/velocity-and-differentiability/file2_non_differentiable.py
new file mode 100644
index 0000000..a91da6b
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/velocity-and-differentiability/file2_non_differentiable.py
@@ -0,0 +1,36 @@
+from manimlib.imports import *
+
+class nd(Scene):
+ def construct(self):
+ ld1 = Line().rotate(20*DEGREES)
+ pd1 = Dot(ld1.get_end(), fill_opacity = 0)
+ pd1.set_stroke(width = 0.5)
+ ld2 = Line().rotate(40*DEGREES).shift(1.4*UP + 1.7*RIGHT)
+ pd2 = Dot(ld2.get_start(), fill_opacity = 1, color = PURPLE)
+ t1 = TextMobject('A discontinuous function.').scale(0.7).shift(UP + 2*RIGHT)
+
+ obj1 = VGroup(*[ld1, pd1, ld2, pd2]).shift(4*LEFT)
+ self.play(FadeIn(obj1), FadeIn(t1))
+ self.wait(2)
+
+ ld3 = ld2.copy().rotate(-60*DEGREES).shift(1.4*DOWN + 0.2*RIGHT)
+ pd3 = Dot(ld1.get_end(), fill_opacity = 1, color = PURPLE)
+ t2 = TextMobject('Graph containing a sharp corner.').scale(0.7).shift( 2*RIGHT)
+
+ obj2 = VGroup(*[ld3, pd3])
+
+ self.play(Transform(VGroup(*[ld2, pd2]), obj2), ReplacementTransform(t1, t2))
+
+ self.wait(2)
+
+ ld4 = Line().rotate(90*DEGREES)
+ pd4 = Dot(ld4.get_center(), color = PURPLE)
+ a1 = Arc(start_angle = -180*DEGREES, angle = 90*DEGREES).move_to(ld4.get_end()).rotate(-90*DEGREES).shift(0.5*(UP+RIGHT))
+ a2 = Arc(start_angle = -180*DEGREES, angle = 90*DEGREES).move_to(ld4.get_start()).rotate(90*DEGREES).shift(0.5*(DOWN+LEFT))
+ t3 = TextMobject('Graph with a vertical line.').scale(0.7).shift(2*RIGHT)
+
+ obj3 = VGroup(*[ld4, pd4, a1, a2]).shift(3*LEFT)
+
+ self.play(FadeOut(obj1), Transform(obj2, obj3), ReplacementTransform(t2, t3))
+ self.wait(2)
+ self.play(FadeOut(obj2), FadeOut(t3))
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/velocity-and-differentiability/file3_tangent_space_curve.gif b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/velocity-and-differentiability/file3_tangent_space_curve.gif
new file mode 100644
index 0000000..06ed70f
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/velocity-and-differentiability/file3_tangent_space_curve.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/velocity-and-differentiability/file3_tangent_space_curve.py b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/velocity-and-differentiability/file3_tangent_space_curve.py
new file mode 100644
index 0000000..c3aecc6
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/velocity-and-differentiability/file3_tangent_space_curve.py
@@ -0,0 +1,33 @@
+from manimlib.imports import *
+
+class tangent(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes()
+ text = TextMobject(r'Tangent', r' to the ', 'space curve', r' \\ at point ', r'$P_{1}$', ' is given by:').scale(0.7).shift(3*UP + 3.5*LEFT)
+ text.set_color_by_tex_to_color_map({
+ "Tangent": YELLOW,
+ '$P_{1}$': RED,
+ 'space curve': BLUE
+ })
+ text.bg=BackgroundRectangle(text,fill_opacity=1, color = BLACK)
+ text_gr =VGroup(text.bg,text)
+ self.set_camera_orientation(phi = 125*DEGREES, theta = 135*DEGREES)
+ h = ParametricFunction(
+ lambda t: np.array([
+ 4*(t**3) + 5,
+ t**2 + 2*(t**4),
+ -2*np.log(2*t)
+ ]), t_min = -3, t_max = 1.18, color = BLUE
+ ).shift(5*LEFT)
+ tgtR = Line((4,3,-2*np.log(2)), (19.5, 16, -4.772588), color=YELLOW)
+ tgtL =Line((4,3,-2*np.log(2)), (-11.5, -10, 2), color=YELLOW)
+ dot = Dot((4,3,-2*np.log(2)), color=RED, radius=0.08)
+ dotl = TextMobject(r'$P_{1}$', color = RED).scale(0.7).shift(2*DOWN + 5*LEFT)
+ self.add_fixed_in_frame_mobjects(text_gr, dotl)
+ self.play(FadeIn(axes),FadeIn(h), FadeIn(dot), FadeIn(dotl))
+ self.wait(2)
+ self.play(FadeIn(tgtL), FadeIn(tgtR))
+ self.begin_ambient_camera_rotation(rate=0.2)
+ self.play(FadeOut(dotl))
+ self.wait(5)
+ self.play(FadeOut(axes), FadeOut(h), FadeOut(text_gr), FadeOut(dot), FadeOut(tgtL), FadeOut(tgtR))
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/README.md b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/README.md
index a321caf..9115c78 100644
--- a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/README.md
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/README.md
@@ -1 +1,14 @@
FSF2020--Somnath Pandit
+
+# **Topics:**
+
+## Double Integral
+Check the note [here](https://math.animations.fossee.in/contents/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals)
+## Fubini's Theorem
+Check the note [here](https://math.animations.fossee.in/contents/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem)
+## Line Integrals
+Check the note [here](https://math.animations.fossee.in/contents/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals)
+## Fundamental Theorem of Line integrals
+Check the note [here](https://math.animations.fossee.in/contents/calculus-of-several-variables/div,-grad,-curl-and-all-that/the-fundamental-theorem-of-line-integrals)
+## Vector Fields
+Check the note [here](https://math.animations.fossee.in/contents/calculus-of-several-variables/integrals-of-multivariable-functions/vector-fields)
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/README.md b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/README.md
new file mode 100644
index 0000000..f86f7e3
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/README.md
@@ -0,0 +1,21 @@
+**file1_area_under_func**
+![file1_area_under_func](gifs/file1_area_under_func.gif)
+
+**file2_volume_under_surface**
+![file2_volume_under_surface](gifs/file2_volume_under_surface.gif)
+
+**file3_y_limit_dependent_on_x**
+![file3_y_limit_dependent_on_x](gifs/file3_y_limit_dependent_on_x.gif)
+
+**file4_non_rect_region**
+![file4_non_rect_region](gifs/file4_non_rect_region.gif)
+
+**file5_elementary_area**
+![file5_elementary_area](gifs/file5_elementary_area.gif)
+
+**file6_doing_integration**
+![file6_doing_integration](gifs/file6_doing_integration.gif)
+
+**file7_int_process_of_example**
+![file7_int_process_of_example](gifs/file7_int_process_of_example.gif)
+
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/YlimitXdependent.gif b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/YlimitXdependent.gif
deleted file mode 100644
index a2bfd9d..0000000
--- a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/YlimitXdependent.gif
+++ /dev/null
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/area_under_func.py b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/file1_area_under_func.py
index 773840c..773840c 100644
--- a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/area_under_func.py
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/file1_area_under_func.py
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/file2_volume_under_surface.py b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/file2_volume_under_surface.py
new file mode 100644
index 0000000..38d41c6
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/file2_volume_under_surface.py
@@ -0,0 +1,349 @@
+from manimlib.imports import *
+
+class SurfacesAnimation(ThreeDScene):
+
+ CONFIG = {
+ "axes_config": {
+ "x_min": 0,
+ "x_max": 7,
+ "y_min": 0,
+ "y_max": 7,
+ "z_min": 0,
+ "z_max": 5,
+ "a":1 ,"b": 6, "c":2 , "d":6,
+ "axes_shift":-3*OUT + 5*LEFT,
+ "x_axis_config": {
+ "tick_frequency": 1,
+ # "include_tip": False,
+ },
+ "y_axis_config": {
+ "tick_frequency": 1,
+ # "include_tip": False,
+ },
+ "z_axis_config": {
+ "tick_frequency": 1,
+ # "include_tip": False,
+ },
+ "num_axis_pieces": 1,
+ },
+ "default_graph_style": {
+ "stroke_width": 2,
+ "stroke_color": WHITE,
+ },
+ "default_surface_config": {
+ "fill_opacity": 0.5,
+ "checkerboard_colors": [LIGHT_GREY],
+ "stroke_width": 0.5,
+ "stroke_color": WHITE,
+ "stroke_opacity": 0.5,
+ },
+ "Func": lambda x,y: 2+y/4+np.sin(x)
+ }
+
+
+ def construct(self):
+
+ self.setup_axes()
+ self.set_camera_orientation(distance=35,
+ phi=80 * DEGREES,
+ theta=-100 * DEGREES,
+ )
+
+ fn_text=TextMobject(
+ "$z=f(x,y)$",
+ color=PINK,
+ stroke_width=1.5
+ )
+ self.add_fixed_in_frame_mobjects(fn_text)
+ fn_text.to_edge(TOP,buff=MED_SMALL_BUFF)
+
+ riemann_sum_text=TextMobject(
+ r"The volume approximated as\\ sum of cuboids",
+ color=BLUE,
+ stroke_width=1.5
+ )
+ riemann_sum_text.to_corner(UR,buff=.2)
+
+ R=TextMobject("R").set_color(BLACK).scale(3)
+ R.move_to(self.axes.input_plane,IN)
+ self.add(R)
+
+ #get the surface
+ surface= self.get_surface(
+ self.axes, lambda x , y:
+ self.Func(x,y)
+ )
+ surface.set_style(
+ fill_opacity=0.8,
+ fill_color=PINK,
+ stroke_width=0.8,
+ stroke_color=WHITE,
+ )
+
+
+ self.begin_ambient_camera_rotation(rate=0.06)
+ self.play(Write(surface))
+ # self.add(surface)
+
+ self.get_lines()
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(riemann_sum_text)
+ self.play(Write(riemann_sum_text))
+
+ cuboids1=self.show_the_riemmann_sum(
+ lambda x,y : np.array([x,y,self.Func(x,y)]),
+ fill_opacity=1,
+ dl=.5,
+ start_color=BLUE,
+ end_color=BLUE_E,
+ )
+ self.play(ShowCreation(cuboids1),run_time=5)
+ self.play(FadeOut(surface))
+
+ cuboids2=self.show_the_riemmann_sum(
+ lambda x,y : np.array([x,y,self.Func(x,y)]),
+ fill_opacity=1,
+ dl=.25,
+ start_color=BLUE,
+ end_color=BLUE_E,
+ )
+ self.play(ReplacementTransform(
+ cuboids1,
+ cuboids2
+ ))
+
+ cuboids3=self.show_the_riemmann_sum(
+ lambda x,y : np.array([x,y,self.Func(x,y)]),
+ fill_opacity=1,
+ dl=.1,
+ start_color=BLUE,
+ end_color=BLUE_E,
+ stroke_width=.1,
+ )
+ self.play(
+ FadeOut(cuboids2),
+ ShowCreation(cuboids3),
+ )
+
+ self.wait(3)
+
+
+
+
+ def get_surface(self,axes, func, **kwargs):
+ config = {
+ "u_min": axes.a,
+ "u_max": axes.b,
+ "v_min": axes.c,
+ "v_max": axes.d,
+ "resolution": (
+ (axes.y_max - axes.y_min) // axes.y_axis.tick_frequency,
+ (axes.x_max - axes.x_min) // axes.x_axis.tick_frequency,
+ ),
+ }
+
+ config.update(self.default_surface_config)
+ config.update(kwargs)
+ return ParametricSurface(
+ lambda x,y : axes.c2p(
+ x, y, func(x, y)
+ ),
+ **config
+ )
+
+ def get_lines(self):
+ axes = self.axes
+
+ surface_corners=[]
+ for x,y,z in self.region_corners:
+ surface_corners.append([x,y,self.Func(x,y)])
+
+ lines=VGroup()
+ for start , end in zip(surface_corners,
+ self.region_corners):
+ lines.add(self.draw_lines(start,end,"#9CDCEB"))
+
+ labels=[
+ (axes.a,0,0),
+ (axes.b,0,0),
+ (0,axes.d,0),
+ (0,axes.c,0)
+ ]
+ self.region_corners[-1]=self.region_corners[0]
+ for start , end in zip(labels,self.region_corners):
+ lines.add(self.draw_lines(start,end,"WHITE"))
+
+ # self.add(lines)
+ self.play(ShowCreation(lines))
+
+
+ def draw_lines(self,start,end,color):
+ start=self.axes.c2p(*start)
+ end=self.axes.c2p(*end)
+ line=DashedLine(start,end,color=color)
+
+ return line
+
+
+ def show_the_riemmann_sum(
+ self,
+ surface,
+ x_min=None,
+ x_max=None,
+ y_min=None,
+ y_max=None,
+ dl=.5,
+ stroke_width=.5,
+ stroke_color=BLACK,
+ fill_opacity=1,
+ start_color=None,
+ end_color=None,
+ ):
+ x_min = x_min if x_min is not None else self.axes.a
+ x_max = x_max if x_max is not None else self.axes.b
+ y_min = y_min if y_min is not None else self.axes.c
+ y_max = y_max if y_max is not None else self.axes.d
+
+ if start_color is None:
+ start_color = BLUE
+ if end_color is None:
+ end_color = BLUE
+
+ cuboids = VGroup()
+ x_range = np.arange(x_min, x_max, dl)
+ y_range = np.arange(y_min, y_max, dl)
+ colors = color_gradient([start_color, end_color], len(x_range))
+ for x, color in zip(x_range, colors):
+ for y in y_range:
+ sample_base = np.array([x ,y ,0])
+ sample_base_dl = np.array([x + dl, y + dl,0])
+ sample_input = np.array([x +0.5*dl, y +0.5*dl,0])
+
+ base_point = self.axes.c2p(*sample_base)
+ base_dx_point = self.axes.c2p(*sample_base_dl)
+
+ surface_val= surface(*sample_input[:2])
+ surface_point = self.axes.c2p(*surface_val)
+
+ points = VGroup(*list(map(VectorizedPoint, [
+ base_point,
+ surface_point,
+ base_dx_point
+ ])))
+
+ # self.add(points)
+ cuboid = Prism(dimensions=[dl,dl,surface_val[-1]])
+ cuboid.replace(points, stretch=True)
+
+ cuboid.set_fill(color, opacity=fill_opacity)
+ cuboid.set_stroke(stroke_color, width=stroke_width)
+ cuboids.add(cuboid)
+
+ return cuboids
+
+
+#-------------------------------------------------------
+ #customize 3d axes
+ def get_three_d_axes(self, include_labels=True, include_numbers=True, **kwargs):
+ config = dict(self.axes_config)
+ config.update(kwargs)
+ axes = ThreeDAxes(**config)
+ axes.set_stroke(width=2)
+
+ if include_numbers:
+ self.add_axes_numbers(axes)
+
+ if include_labels:
+ self.add_axes_labels(axes)
+
+ # Adjust axis orientation
+ axes.x_axis.rotate(
+ 90 * DEGREES, RIGHT,
+ about_point=axes.c2p(0, 0, 0),
+ )
+ axes.y_axis.rotate(
+ 90 * DEGREES, UP,
+ about_point=axes.c2p(0, 0, 0),
+ )
+
+ # Add xy-plane
+ input_plane = self.get_surface(
+ axes, lambda x, t: 0
+ )
+ input_plane.set_style(
+ fill_opacity=0.5,
+ fill_color=TEAL,
+ stroke_width=0,
+ stroke_color=WHITE,
+ )
+
+ axes.input_plane = input_plane
+
+ self.region_corners=[
+ input_plane.get_corner(pos) for pos in (DL,DR,UL,UR)]
+
+ return axes
+
+
+ def setup_axes(self):
+ axes = self.get_three_d_axes(include_labels=True)
+ axes.add(axes.input_plane)
+ axes.scale(1)
+ # axes.center()
+ axes.shift(axes.axes_shift)
+
+ self.add(axes)
+ self.axes = axes
+
+ def add_axes_numbers(self, axes):
+ x_axis = axes.x_axis
+ y_axis = axes.y_axis
+ tex_vals_x = [
+ ("a", axes.a),
+ ("b", axes.b),
+ ]
+ tex_vals_y=[
+ ("c", axes.c),
+ ("d", axes.d)
+ ]
+ x_labels = VGroup()
+ y_labels = VGroup()
+ for tex, val in tex_vals_x:
+ label = TexMobject(tex)
+ label.scale(1)
+ label.next_to(x_axis.n2p(val), DOWN)
+ x_labels.add(label)
+ x_axis.add(x_labels)
+ x_axis.numbers = x_labels
+
+ for tex, val in tex_vals_y:
+ label = TexMobject(tex)
+ label.scale(1.5)
+ label.next_to(y_axis.n2p(val), LEFT)
+ label.rotate(90 * DEGREES)
+ y_labels.add(label)
+
+ y_axis.add(y_labels)
+ y_axis.numbers = y_labels
+
+ return axes
+
+ def add_axes_labels(self, axes):
+ x_label = TexMobject("x")
+ x_label.next_to(axes.x_axis.get_end(), RIGHT)
+ axes.x_axis.label = x_label
+
+ y_label = TextMobject("y")
+ y_label.rotate(90 * DEGREES, OUT)
+ y_label.next_to(axes.y_axis.get_end(), UP)
+ axes.y_axis.label = y_label
+
+ z_label = TextMobject("z")
+ z_label.rotate(90 * DEGREES, RIGHT)
+ z_label.next_to(axes.z_axis.get_zenith(), RIGHT)
+ axes.z_axis.label = z_label
+ for axis in axes:
+ axis.add(axis.label)
+ return axes
+
+
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/y_limit_dependent_on_x.py b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/file3_y_limit_dependent_on_x.py
index 4894ebf..f755495 100644
--- a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/y_limit_dependent_on_x.py
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/file3_y_limit_dependent_on_x.py
@@ -29,7 +29,7 @@ class YlimitXdependent(GraphScene):
line_eqn=TextMobject("2x+y=2").move_to(self.graph_origin+.8*X+Y).rotate(np.arctan(-2))
self.line=line
- caption=TextMobject(r"See the value of $y$ \\ is changing with $x$").move_to(self.graph_origin+1.2*X+1.8*Y)
+ caption=TextMobject(r"The value of $y$ is\\ changing with $x$").move_to(self.graph_origin+1.2*X+1.8*Y)
self.play(ShowCreation(line),Write(line_eqn))
# self.show_area()
self.show_rects()
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/non_rect_region.py b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/file4_non_rect_region.py
index 793a000..793a000 100644
--- a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/non_rect_region.py
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/file4_non_rect_region.py
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/elementary_area.py b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/file5_elementary_area.py
index 362b6f8..362b6f8 100644
--- a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/elementary_area.py
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/file5_elementary_area.py
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/file6_doing_integration.py b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/file6_doing_integration.py
new file mode 100644
index 0000000..5a8cec0
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/file6_doing_integration.py
@@ -0,0 +1,355 @@
+from manimlib.imports import *
+
+class IntegrationProcess(SpecialThreeDScene):
+
+ CONFIG = {
+ "axes_config": {
+ "x_min": 0,
+ "x_max": 7,
+ "y_min": 0,
+ "y_max": 7,
+ "z_min": 0,
+ "z_max": 4,
+ "a":1 ,"b": 6, "c":2 , "d":6,
+ "axes_shift":-3*OUT,
+ "x_axis_config": {
+ "tick_frequency": 1,
+ # "include_tip": False,
+ },
+ "y_axis_config": {
+ "tick_frequency": 1,
+ # "include_tip": False,
+ },
+ "z_axis_config": {
+ "tick_frequency": 1,
+ # "include_tip": False,
+ },
+ "num_axis_pieces": 1,
+ },
+ "default_graph_style": {
+ "stroke_width": 2,
+ "stroke_color": WHITE,
+ },
+ "default_surface_config": {
+ "fill_opacity": 0.5,
+ "checkerboard_colors": [LIGHT_GREY],
+ "stroke_width": 0.5,
+ "stroke_color": WHITE,
+ "stroke_opacity": 0.5,
+ },
+ "Func": lambda x,y: 2+y/4+np.cos(x/1.4)
+ }
+
+
+ def construct(self):
+
+ self.setup_axes()
+ axes=self.axes
+
+ self.camera.frame_center.shift(axes.c2p(3,4,1.7))
+ self.set_camera_orientation(distance=35,
+ phi= 80 * DEGREES,
+ theta= -80 * DEGREES,
+ gamma = 0 * DEGREES
+ )
+
+ fn_text=TextMobject("$z=f(x,y)$").set_color(PINK)
+ self.add_fixed_in_frame_mobjects(fn_text)
+
+
+ R=TextMobject("R").set_color(BLACK).scale(3)
+ R.move_to(axes.input_plane,IN)
+ self.add(R)
+
+ # get the surface
+ surface= self.get_surface(
+ axes, lambda x , y:
+ self.Func(x,y)
+ )
+ surface.set_style(
+ fill_opacity=.65,
+ fill_color=PINK,
+ stroke_width=0.8,
+ stroke_color=WHITE,
+ )
+ fn_text.next_to(surface,UP,buff=MED_LARGE_BUFF)
+ slice_curve=(self.get_y_slice_graph(
+ axes,self.Func,5,color=YELLOW))
+
+
+ self.begin_ambient_camera_rotation(rate=0.08)
+ # self.play(Write(surface))
+ self.add(surface)
+
+ self.get_lines()
+
+ self.show_process(axes)
+
+ self.wait(3)
+
+
+
+ def show_process(self,axes):
+ y_tracker = ValueTracker(axes.c)
+ self.y_tracker=y_tracker
+ y=y_tracker.get_value
+
+ graph = always_redraw(
+ lambda: self.get_y_slice_graph(
+ axes, self.Func, y(),
+ stroke_color=YELLOW,
+ stroke_width=4,
+ )
+ )
+ graph.suspend_updating()
+
+
+ plane = always_redraw(lambda: Polygon(
+ *[
+ axes.c2p(x,y(),self.Func(x,y()))
+ for x in np.arange(axes.a,axes.b,0.01)
+ ],
+ *[
+ axes.c2p(x, y(), 0)
+ for x in [ axes.b, axes.a,]
+ ],
+ stroke_width=2,
+ fill_color=BLUE_D,
+ fill_opacity=.4,
+ ))
+
+ plane_side1 = always_redraw(lambda: Polygon(
+ *[
+ axes.c2p(axes.a,y,self.Func(axes.a,y))
+ for y in np.arange(axes.c,y(),0.01)
+ ],
+ *[
+ axes.c2p(axes.a, y, 0)
+ for y in [ y(),axes.c, ]
+ ],
+ stroke_width=2.5,
+ fill_color=BLUE_C,
+ fill_opacity=.2,
+ ))
+ plane_side2 = always_redraw(lambda: Polygon(
+ *[
+ axes.c2p(axes.b,y,self.Func(axes.b,y))
+ for y in np.arange(axes.c,y(),0.01)
+ ],
+ *[
+ axes.c2p(axes.b, y, 0)
+ for y in [y(),axes.c,]
+ ],
+ stroke_width=2.5,
+ fill_color=BLUE_E,
+ fill_opacity=.45,
+ ))
+ plane.suspend_updating()
+ plane_side1.suspend_updating()
+ plane_side2.suspend_updating()
+
+ self.play(Write(VGroup(graph,plane)),run_time=2)
+ self.add(plane.copy(),plane_side1,plane_side2)
+
+
+ plane_side1.resume_updating()
+ plane_side2.resume_updating()
+
+ self.move_camera(
+ distance=30,
+ phi= 85 * DEGREES,
+ theta= -10 * DEGREES,
+ run_time=1.5
+ )
+ self.play(
+ ApplyMethod(
+ y_tracker.set_value, axes.d,
+ rate_func=linear,
+ run_time=6,
+ )
+ )
+ plane.suspend_updating()
+ plane_side1.suspend_updating()
+ plane_side2.suspend_updating()
+
+
+
+ def get_y_slice_graph(self, axes, func, y, **kwargs):
+ config = dict()
+ config.update(self.default_graph_style)
+ config.update({
+ "t_min": axes.a,
+ "t_max": axes.b,
+ })
+ config.update(kwargs)
+ slice_curve=ParametricFunction(
+ lambda x: axes.c2p(
+ x, y, func(x, y)
+ ),
+ **config,
+ )
+ return slice_curve
+
+
+ def get_surface(self,axes, func, **kwargs):
+ config = {
+ "u_min": axes.a,
+ "u_max": axes.b,
+ "v_min": axes.c,
+ "v_max": axes.d,
+ "resolution": (
+ (axes.y_max - axes.y_min) // axes.y_axis.tick_frequency,
+ (axes.x_max - axes.x_min) // axes.x_axis.tick_frequency,
+ ),
+ }
+
+ config.update(self.default_surface_config)
+ config.update(kwargs)
+ return ParametricSurface(
+ lambda x,y : axes.c2p(
+ x, y, func(x, y)
+ ),
+ **config
+ )
+
+ def get_lines(self):
+ axes = self.axes
+
+ surface_corners=[]
+ for x,y,z in self.region_corners:
+ surface_corners.append([x,y,self.Func(x,y)])
+
+ lines=VGroup()
+ for start , end in zip(surface_corners,
+ self.region_corners):
+ lines.add(self.draw_lines(start,end,"RED"))
+
+ labels=[
+ (axes.a,0,0),
+ (axes.b,0,0),
+ (0,axes.d,0),
+ (0,axes.c,0)
+ ]
+ self.region_corners[-1]=self.region_corners[0]
+ for start , end in zip(labels,
+ self.region_corners):
+ lines.add(self.draw_lines(start,end,"WHITE"))
+ self.add(lines)
+
+
+ def draw_lines(self,start,end,color):
+ start=self.axes.c2p(*start)
+ end=self.axes.c2p(*end)
+ line=DashedLine(start,end,color=color)
+
+ return line
+
+
+#------------------------------------------------------------
+ #customize 3d axes
+ def get_three_d_axes(self, include_labels=True, include_numbers=True, **kwargs):
+ config = dict(self.axes_config)
+ config.update(kwargs)
+ axes = ThreeDAxes(**config)
+ axes.set_stroke(width=2)
+
+ if include_numbers:
+ self.add_axes_numbers(axes)
+
+ if include_labels:
+ self.add_axes_labels(axes)
+
+ # Adjust axis orientation
+ axes.x_axis.rotate(
+ 90 * DEGREES, RIGHT,
+ about_point=axes.c2p(0, 0, 0),
+ )
+ axes.y_axis.rotate(
+ 90 * DEGREES, UP,
+ about_point=axes.c2p(0, 0, 0),
+ )
+
+ # Add xy-plane
+ input_plane = self.get_surface(
+ axes, lambda x, t: 0
+ )
+ input_plane.set_style(
+ fill_opacity=0.5,
+ fill_color=TEAL,
+ stroke_width=0,
+ stroke_color=WHITE,
+ )
+
+ axes.input_plane = input_plane
+
+ self.region_corners=[
+ input_plane.get_corner(pos) for pos in (DL,DR,UL,UR)]
+
+ return axes
+
+
+ def setup_axes(self):
+ axes = self.get_three_d_axes(include_labels=True)
+ axes.add(axes.input_plane)
+ axes.scale(1)
+ # axes.center()
+ axes.shift(axes.axes_shift)
+
+ self.add(axes)
+
+ self.axes = axes
+
+ def add_axes_numbers(self, axes):
+ x_axis = axes.x_axis
+ y_axis = axes.y_axis
+ tex_vals_x = [
+ ("a", axes.a),
+ ("b", axes.b),
+ ]
+ tex_vals_y=[
+ ("c", axes.c),
+ ("d", axes.d)
+ ]
+ x_labels = VGroup()
+ y_labels = VGroup()
+ for tex, val in tex_vals_x:
+ label = TexMobject(tex)
+ label.scale(1)
+ label.next_to(x_axis.n2p(val), DOWN)
+ x_labels.add(label)
+ x_axis.add(x_labels)
+ x_axis.numbers = x_labels
+
+ for tex, val in tex_vals_y:
+ label = TexMobject(tex)
+ label.scale(1.5)
+ label.next_to(y_axis.n2p(val), LEFT)
+ label.rotate(90 * DEGREES)
+ y_labels.add(label)
+
+ y_axis.add(y_labels)
+ y_axis.numbers = y_labels
+
+ return axes
+
+ def add_axes_labels(self, axes):
+ x_label = TexMobject("x")
+ x_label.next_to(axes.x_axis.get_end(), RIGHT)
+ axes.x_axis.label = x_label
+
+ y_label = TextMobject("y")
+ y_label.rotate(90 * DEGREES, OUT)
+ y_label.next_to(axes.y_axis.get_end(), UP)
+ axes.y_axis.label = y_label
+
+ z_label = TextMobject("z")
+ z_label.rotate(90 * DEGREES, RIGHT)
+ z_label.next_to(axes.z_axis.get_zenith(), RIGHT)
+ axes.z_axis.label = z_label
+ for axis in axes:
+ axis.add(axis.label)
+ return axes
+
+
+
+ #uploaded by Somnath Pandit.FSF2020_Double_Integral
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/file7_int_process_of_example.py b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/file7_int_process_of_example.py
new file mode 100644
index 0000000..f733761
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/file7_int_process_of_example.py
@@ -0,0 +1,366 @@
+from manimlib.imports import *
+
+class IntegrationProcess(SpecialThreeDScene):
+
+ CONFIG = {
+ "axes_config": {
+ "x_min": 0,
+ "x_max": 5,
+ "y_min": 0,
+ "y_max": 7,
+ "z_min": 0,
+ "z_max": 3,
+ "a":0 ,"b":4 , "c":0 , "d":6,
+ "axes_shift":1.5*IN+2*LEFT+4*DOWN,
+ "x_axis_config": {
+ "tick_frequency": 1,
+ # "include_tip": False,
+ },
+ "y_axis_config": {
+ "tick_frequency": 1,
+ # "include_tip": False,
+ },
+ "z_axis_config": {
+ "tick_frequency": 1,
+ # "include_tip": False,
+ },
+ "num_axis_pieces": 1,
+ },
+ "default_graph_style": {
+ "stroke_width": 2,
+ "stroke_color": WHITE,
+ },
+ "default_surface_config": {
+ "fill_opacity": 0.5,
+ "checkerboard_colors": [LIGHT_GREY],
+ "stroke_width": 0.5,
+ "stroke_color": WHITE,
+ "stroke_opacity": 0.5,
+ },
+ "Func": lambda x,y: 2*(1+(x+y)/10)
+ }
+
+
+ def construct(self):
+
+ self.setup_axes()
+ axes=self.axes
+ self.set_camera_orientation(#distance=35,
+ phi=60 * DEGREES,
+ theta=10 * DEGREES,
+ )
+
+ fn_text=TextMobject("$z=(1+x+y)$").set_color(PINK)
+ self.add_fixed_in_frame_mobjects(fn_text)
+ fn_text.to_edge(TOP,buff=.1)
+ self.fn_text=fn_text
+
+ R=TextMobject("R").set_color(BLACK).scale(3).rotate(PI/2)
+ R.move_to(axes.input_plane,IN)
+ self.add(R)
+
+ #get the surface
+ surface= self.get_surface(
+ axes, lambda x , y:
+ self.Func(x,y)
+ )
+ surface.set_style(
+ fill_opacity=0.75,
+ fill_color=PINK,
+ stroke_width=0.8,
+ stroke_color=WHITE,
+ )
+
+ slice_curve=(self.get_y_slice_graph(
+ axes,self.Func,5,color=YELLOW))
+
+
+ self.begin_ambient_camera_rotation(rate=0.04)
+ # self.play(Write(surface))
+ self.add(surface)
+
+ self.get_lines()
+
+ self.show_process(axes)
+
+ self.wait()
+
+
+
+ def show_process(self,axes):
+ y_tracker = ValueTracker(axes.c)
+ self.y_tracker=y_tracker
+ y=y_tracker.get_value
+ graph = always_redraw(
+ lambda: self.get_y_slice_graph(
+ axes, self.Func, y(),
+ stroke_color=YELLOW,
+ stroke_width=4,
+ )
+ )
+ graph.suspend_updating()
+
+ plane = always_redraw(lambda: Polygon(
+ *[
+ axes.c2p(x,y(),self.Func(x,y()))
+ for x in np.arange(axes.a,axes.b,0.01)
+ ],
+ *[
+ axes.c2p(x, y(), 0)
+ for x in [ axes.b, axes.a,]
+ ],
+ stroke_width=0,
+ fill_color=BLUE_E,
+ fill_opacity=.65,
+ ))
+ plane_side1 = always_redraw(lambda: Polygon(
+ *[
+ axes.c2p(axes.a,y,self.Func(axes.a,y))
+ for y in np.arange(axes.c,y(),0.01)
+ ],
+ *[
+ axes.c2p(axes.a, y, 0)
+ for y in [ y(),axes.c, ]
+ ],
+ stroke_width=2.5,
+ fill_color=BLUE_C,
+ fill_opacity=.2,
+ ))
+ plane_side2 = always_redraw(lambda: Polygon(
+ *[
+ axes.c2p(axes.b,y,self.Func(axes.b,y))
+ for y in np.arange(axes.c,y(),0.01)
+ ],
+ *[
+ axes.c2p(axes.b, y, 0)
+ for y in [y(),axes.c,]
+ ],
+ stroke_width=2.5,
+ fill_color=BLUE_E,
+ fill_opacity=.45,
+ ))
+ plane.suspend_updating()
+ plane_side1.suspend_updating()
+ plane_side2.suspend_updating()
+
+ first_x_text=TextMobject("First the $x$ integration..",color=YELLOW)
+ first_x_text.to_corner(UR,buff=1.1)
+
+ x_func=TextMobject("$\\frac 3 2 + y$",color=BLUE)
+ '''x_func.next_to(self.fn_text,DOWN)
+ x_func.align_to(self.fn_text,LEFT)'''
+ x_func.to_edge(LEFT,buff=1)
+
+ then_y_text=TextMobject("Then the $y$ integration..",color=YELLOW)
+ then_y_text.to_corner(UR,buff=1.1)
+
+ self.add_fixed_in_frame_mobjects(first_x_text)
+ self.play(Write(first_x_text))
+ self.add_fixed_in_frame_mobjects(x_func)
+ self.play(
+ Write(VGroup(graph,plane,x_func)),
+ run_time=3
+ )
+
+ self.wait()
+ self.remove(first_x_text)
+ self.add_fixed_in_frame_mobjects(then_y_text)
+ self.play(Write(then_y_text))
+ self.add(plane.copy(),plane_side1,plane_side2)
+ graph.resume_updating()
+ plane.resume_updating()
+ plane_side1.resume_updating()
+ plane_side2.resume_updating()
+ self.play(
+ ApplyMethod(
+ y_tracker.set_value, axes.d,
+ rate_func=linear,
+ run_time=6,
+ )
+ )
+
+ graph.suspend_updating()
+ plane.suspend_updating()
+ plane_side1.suspend_updating()
+ plane_side2.suspend_updating()
+
+
+ def get_y_slice_graph(self, axes, func, y, **kwargs):
+ config = dict()
+ config.update(self.default_graph_style)
+ config.update({
+ "t_min": axes.a,
+ "t_max": axes.b,
+ })
+ config.update(kwargs)
+ slice_curve=ParametricFunction(
+ lambda x: axes.c2p(
+ x, y, func(x, y)
+ ),
+ **config,
+ )
+ return slice_curve
+
+
+ def get_surface(self,axes, func, **kwargs):
+ config = {
+ "u_min": axes.a,
+ "u_max": axes.b,
+ "v_min": axes.c,
+ "v_max": axes.d,
+ "resolution": (
+ (axes.y_max - axes.y_min) // axes.y_axis.tick_frequency,
+ (axes.x_max - axes.x_min) // axes.x_axis.tick_frequency,
+ ),
+ }
+
+ config.update(self.default_surface_config)
+ config.update(kwargs)
+ return ParametricSurface(
+ lambda x,y : axes.c2p(
+ x, y, func(x, y)
+ ),
+ **config
+ )
+
+ def get_lines(self):
+ axes = self.axes
+
+ surface_corners=[]
+ for x,y,z in self.region_corners:
+ surface_corners.append([x,y,self.Func(x,y)])
+
+ lines=VGroup()
+ for start , end in zip(surface_corners,
+ self.region_corners):
+ lines.add(self.draw_lines(start,end,"RED"))
+
+ labels=[
+ (axes.a,0,0),
+ (axes.b,0,0),
+ (0,axes.d,0),
+ (0,axes.c,0)
+ ]
+ self.region_corners[-1]=self.region_corners[0]
+ for start , end in zip(labels,
+ self.region_corners):
+ lines.add(self.draw_lines(start,end,"WHITE"))
+ self.add(lines)
+
+
+ def draw_lines(self,start,end,color):
+ start=self.axes.c2p(*start)
+ end=self.axes.c2p(*end)
+ line=DashedLine(start,end,color=color)
+
+ return line
+
+
+#------------------------------------------------------------
+ #customize 3d axes
+ def get_three_d_axes(self, include_labels=True, include_numbers=True, **kwargs):
+ config = dict(self.axes_config)
+ config.update(kwargs)
+ axes = ThreeDAxes(**config)
+ axes.set_stroke(width=2)
+
+ if include_numbers:
+ self.add_axes_numbers(axes)
+
+ if include_labels:
+ self.add_axes_labels(axes)
+
+ # Adjust axis orientation
+ axes.x_axis.rotate(
+ 90 * DEGREES, LEFT,
+ about_point=axes.c2p(0, 0, 0),
+ )
+ axes.y_axis.rotate(
+ 90 * DEGREES, UP,
+ about_point=axes.c2p(0, 0, 0),
+ )
+
+ # Add xy-plane
+ input_plane = self.get_surface(
+ axes, lambda x, t: 0
+ )
+ input_plane.set_style(
+ fill_opacity=0.3,
+ fill_color=TEAL,
+ stroke_width=.2,
+ stroke_color=WHITE,
+ )
+
+ axes.input_plane = input_plane
+
+ self.region_corners=[
+ input_plane.get_corner(pos) for pos in (DL,DR,UL,UR)]
+
+ return axes
+
+
+ def setup_axes(self):
+ axes = self.get_three_d_axes(include_labels=True)
+ axes.add(axes.input_plane)
+ axes.scale(1)
+ # axes.center()
+ axes.shift(axes.axes_shift)
+
+ self.add(axes)
+ self.axes = axes
+
+ def add_axes_numbers(self, axes):
+ x_axis = axes.x_axis
+ y_axis = axes.y_axis
+ tex_vals_x = [
+
+ ("1", axes.b),
+ ]
+ tex_vals_y=[
+
+ ("2", axes.d)
+ ]
+ x_labels = VGroup()
+ y_labels = VGroup()
+ for tex, val in tex_vals_x:
+ label = TexMobject(tex)
+ label.scale(1)
+ label.next_to(x_axis.n2p(val), DOWN)
+ label.rotate(180 * DEGREES)
+ x_labels.add(label)
+ x_axis.add(x_labels)
+ x_axis.numbers = x_labels
+
+ for tex, val in tex_vals_y:
+ label = TexMobject(tex)
+ label.scale(1)
+ label.next_to(y_axis.n2p(val), LEFT)
+ label.rotate(90 * DEGREES)
+ y_labels.add(label)
+
+ y_axis.add(y_labels)
+ y_axis.numbers = y_labels
+
+ return axes
+
+ def add_axes_labels(self, axes):
+ x_label = TexMobject("x")
+ x_label.next_to(axes.x_axis.get_end(), RIGHT)
+ axes.x_axis.label = x_label
+
+ y_label = TextMobject("y")
+ y_label.rotate(90 * DEGREES, OUT)
+ y_label.next_to(axes.y_axis.get_end(), UP)
+ axes.y_axis.label = y_label
+
+ z_label = TextMobject("z")
+ z_label.rotate(90 * DEGREES, LEFT)
+ z_label.next_to(axes.z_axis.get_zenith(), LEFT)
+ axes.z_axis.label = z_label
+ for axis in axes:
+ axis.add(axis.label)
+ return axes
+
+
+
+ #uploaded by Somnath Pandit.FSF2020_Double_Integral
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/gifs/file1_area_under_func.gif b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/gifs/file1_area_under_func.gif
new file mode 100644
index 0000000..223218b
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/gifs/file1_area_under_func.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/gifs/file2_volume_under_surface.gif b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/gifs/file2_volume_under_surface.gif
new file mode 100644
index 0000000..1455573
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/gifs/file2_volume_under_surface.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/gifs/file3_y_limit_dependent_on_x.gif b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/gifs/file3_y_limit_dependent_on_x.gif
new file mode 100644
index 0000000..dcfacb6
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/gifs/file3_y_limit_dependent_on_x.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/gifs/file4_non_rect_region.gif b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/gifs/file4_non_rect_region.gif
new file mode 100644
index 0000000..c8e7c8c
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/gifs/file4_non_rect_region.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/gifs/file5_elementary_area.gif b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/gifs/file5_elementary_area.gif
new file mode 100644
index 0000000..5c9ac03
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/gifs/file5_elementary_area.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/gifs/file6_doing_integration.gif b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/gifs/file6_doing_integration.gif
new file mode 100644
index 0000000..7a9271b
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/gifs/file6_doing_integration.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/gifs/file7_int_process_of_example.gif b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/gifs/file7_int_process_of_example.gif
new file mode 100644
index 0000000..9fbdde8
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/gifs/file7_int_process_of_example.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/README.md b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/README.md
new file mode 100644
index 0000000..3aa9be2
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/README.md
@@ -0,0 +1,14 @@
+
+**file1_surface1**
+![file1_surface1](gifs/file1_surface1.gif)
+
+**file2_surface2**
+![file2_surface2](gifs/file2_surface2.gif)
+
+**file3_iteration_methods**
+![file3_iteration_methods](gifs/file3_iteration_methods.gif)
+
+**file4_curvy_limits**
+![file4_curvy_limits](gifs/file4_curvy_region.gif)
+
+
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/file1_surface1.py b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/file1_surface1.py
new file mode 100644
index 0000000..a590a53
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/file1_surface1.py
@@ -0,0 +1,232 @@
+from manimlib.imports import *
+
+class SurfacesAnimation(ThreeDScene):
+
+ CONFIG = {
+ "axes_config": {
+ "x_min": 0,
+ "x_max": 4,
+ "y_min": 0,
+ "y_max": 4,
+ "z_min": -4,
+ "z_max": 4,
+ "a":0 ,"b": 4, "c":0 , "d":4,
+ "axes_shift":IN+LEFT,
+ "x_axis_config": {
+ "tick_frequency": 1,
+ "include_tip": False,
+ },
+ "y_axis_config": {
+ "tick_frequency": 1,
+ "include_tip": False,
+ },
+ "z_axis_config": {
+ "tick_frequency": 1,
+ # "include_tip": False,
+ },
+ "num_axis_pieces": 1,
+ },
+ "default_graph_style": {
+ "stroke_width": 2,
+ "stroke_color": WHITE,
+ },
+ "default_surface_config": {
+ "fill_opacity": 0.5,
+ "checkerboard_colors": [LIGHT_GREY],
+ "stroke_width": 0.5,
+ "stroke_color": WHITE,
+ "stroke_opacity": 0.5,
+ },
+ "Func": lambda x,y: 5*(x**2-y**2)/((1e-4+x**2+y**2)**2)
+ }
+
+
+ def construct(self):
+
+ self.setup_axes()
+ self.set_camera_orientation(#distance=10,
+ phi=80 * DEGREES,
+ theta=35 * DEGREES,
+ )
+
+ fn_text=TextMobject("$z=\dfrac{x^2-y^2}{(x^2+y^2)^2}$").set_color(BLUE)
+ fn_text.to_corner(UR,buff=1)
+ self.add_fixed_in_frame_mobjects(fn_text)
+
+ R=TextMobject("R").set_color(BLACK).scale(2).rotate(180*DEGREES , OUT)
+ R.move_to(self.axes.input_plane,IN)
+ self.add(R)
+
+ #get the surface
+ surface= self.get_surface(
+ self.axes, lambda x , y:
+ self.Func(x,y)
+ )
+ surface.set_style(
+ fill_opacity=0.6,
+ fill_color=BLUE_E,
+ stroke_width=0.8,
+ stroke_color=WHITE,
+ )
+
+
+ self.begin_ambient_camera_rotation(rate=0.2)
+ self.play(Write(surface))
+
+ self.get_lines()
+ self.wait(4)
+
+ def get_surface(self,axes, func, **kwargs):
+ config = {
+ "u_min": axes.x_max,
+ "u_max": axes.x_min,
+ "v_min": axes.y_max,
+ "v_max": axes.y_min,
+ "resolution": (10,10),
+ }
+
+ config.update(self.default_surface_config)
+ config.update(kwargs)
+ return ParametricSurface(
+ lambda x,y : axes.c2p(
+ x, y, func(x, y)
+ ),
+ **config
+ )
+
+ def get_lines(self):
+ axes = self.axes
+ labels=[axes.x_axis.n2p(axes.a), axes.x_axis.n2p(axes.b), axes.y_axis.n2p(axes.c),
+ axes.y_axis.n2p(axes.d)]
+
+
+ surface_corners=[]
+ for x,y,z in self.region_corners:
+ surface_corners.append([x,y,self.Func(x,y)])
+
+ lines=VGroup()
+ for start , end in zip(surface_corners,
+ self.region_corners):
+ lines.add(self.draw_lines(start,end,"YELLOW"))
+
+ for start , end in zip(labels,
+ self.region_corners):
+ # lines.add(self.draw_lines(start,end,"BLUE"))
+ # print (start,end)
+ pass
+ self.play(ShowCreation(lines))
+
+
+ def draw_lines(self,start,end,color):
+ start=self.axes.c2p(*start)
+ end=self.axes.c2p(*end)
+ line=DashedLine(start,end,color=color)
+
+ return line
+
+ def get_three_d_axes(self, include_labels=True, include_numbers=True, **kwargs):
+ config = dict(self.axes_config)
+ config.update(kwargs)
+ axes = ThreeDAxes(**config)
+ axes.set_stroke(width=2)
+
+ if include_numbers:
+ self.add_axes_numbers(axes)
+
+ if include_labels:
+ self.add_axes_labels(axes)
+
+ # Adjust axis orientation
+ axes.x_axis.rotate(
+ 90 * DEGREES, LEFT,
+ about_point=axes.c2p(0, 0, 0),
+ )
+ axes.y_axis.rotate(
+ 90 * DEGREES, UP,
+ about_point=axes.c2p(0, 0, 0),
+ )
+
+ # Add xy-plane
+ input_plane = self.get_surface(
+ axes, lambda x, t: 0
+ )
+ input_plane.set_style(
+ fill_opacity=0.3,
+ fill_color=PINK,
+ stroke_width=.2,
+ stroke_color=WHITE,
+ )
+
+ axes.input_plane = input_plane
+
+ self.region_corners=[
+ input_plane.get_corner(pos) for pos in (DL,DR,UR,UL)]
+
+ return axes
+
+
+ def setup_axes(self):
+ axes = self.get_three_d_axes(include_labels=True)
+ axes.add(axes.input_plane)
+ axes.scale(1)
+ # axes.center()
+ axes.shift(axes.axes_shift)
+
+ self.add(axes)
+ self.axes = axes
+
+ def add_axes_numbers(self, axes):
+ x_axis = axes.x_axis
+ y_axis = axes.y_axis
+ tex_vals_x = [
+ ("a", axes.a+.4),
+ ("b", axes.b),
+ ]
+ tex_vals_y=[
+ ("c", axes.c+.4),
+ ("d", axes.d)
+ ]
+ x_labels = VGroup()
+ y_labels = VGroup()
+ for tex, val in tex_vals_x:
+ label = TexMobject(tex)
+ label.scale(1)
+ label.next_to(x_axis.n2p(val), DOWN)
+ label.rotate(180 * DEGREES)
+ x_labels.add(label)
+ x_axis.add(x_labels)
+ x_axis.numbers = x_labels
+
+ for tex, val in tex_vals_y:
+ label = TexMobject(tex)
+ label.scale(1)
+ label.next_to(y_axis.n2p(val), LEFT)
+ label.rotate(90 * DEGREES)
+ y_labels.add(label)
+
+ y_axis.add(y_labels)
+ y_axis.numbers = y_labels
+
+ return axes
+
+ def add_axes_labels(self, axes):
+ x_label = TexMobject("x")
+ x_label.next_to(axes.x_axis.get_end(), RIGHT)
+ axes.x_axis.label = x_label
+
+ y_label = TextMobject("y")
+ y_label.rotate(90 * DEGREES, OUT)
+ y_label.next_to(axes.y_axis.get_end(), UP)
+ axes.y_axis.label = y_label
+
+ z_label = TextMobject("z")
+ z_label.rotate(90 * DEGREES, LEFT)
+ z_label.next_to(axes.z_axis.get_zenith(), LEFT)
+ axes.z_axis.label = z_label
+ for axis in axes:
+ axis.add(axis.label)
+ return axes
+
+#uploaded by Somnath Pandit.FSF2020_Fubini's_Theorem
+
+
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/file2_surface2.py b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/file2_surface2.py
new file mode 100644
index 0000000..3160fdb
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/file2_surface2.py
@@ -0,0 +1,290 @@
+from manimlib.imports import *
+
+class SurfacesAnimation(ThreeDScene):
+
+ CONFIG = {
+ "axes_config": {
+ "x_min": 0,
+ "x_max": 4,
+ "y_min": 0,
+ "y_max": 4,
+ "z_min": -2,
+ "z_max": 4,
+ "a":0 ,"b": 4, "c":0 , "d":4,
+ "axes_shift":IN+2*LEFT+2*DOWN,
+ "x_axis_config": {
+ "tick_frequency": 1,
+ "include_tip": False,
+ },
+ "y_axis_config": {
+ "tick_frequency": 1,
+ "include_tip": False,
+ },
+ "z_axis_config": {
+ "tick_frequency": 1,
+ # "include_tip": False,
+ },
+ "num_axis_pieces": 1,
+ },
+ "default_graph_style": {
+ "stroke_width": 2,
+ "stroke_color": WHITE,
+ },
+ "default_surface_config": {
+ "fill_opacity": 0.5,
+ "checkerboard_colors": [LIGHT_GREY],
+ "stroke_width": 0.5,
+ "stroke_color": WHITE,
+ "stroke_opacity": 0.5,
+ },
+ "Func": lambda x,y: x*y/4
+ }
+
+
+ def construct(self):
+
+ self.setup_axes()
+ self.set_camera_orientation(
+ distance=30,
+ phi=75 * DEGREES,
+ theta=20 * DEGREES,
+ )
+
+ fn_text=TextMobject("$z=xy$").set_color(BLUE).scale(1.5)
+ fn_text.to_corner(UR,buff=2)
+ self.add_fixed_in_frame_mobjects(fn_text)
+
+
+ #get the surface
+ surface= self.get_surface(
+ self.axes, lambda x , y:
+ self.Func(x,y)
+ )
+ surface.set_style(
+ fill_opacity=.5,
+ fill_color=BLUE_E,
+ stroke_width=0.4,
+ stroke_color=WHITE,
+ )
+ #get boundary curves
+ c1=self.get_curve(
+ self.axes, lambda x: x**2/4
+ )
+ c1_label=TextMobject("$y=x^2$").next_to(c1,IN+OUT).shift(DOWN+RIGHT)
+ c1_label.rotate(PI)
+ c1_group=VGroup(c1,c1_label).set_color(ORANGE)
+
+ c2=self.get_curve(
+ self.axes, lambda x: x
+ ).set_color(PINK)
+ c2_label=TextMobject("$y=x$").next_to(c2,IN+OUT)
+ c2_label.rotate(PI/2,about_point=(c2_label.get_corner(UL)))
+ c2_group=VGroup(c2,c2_label).set_color(YELLOW_E)
+
+
+
+ self.add(c1,c2,c1_label,c2_label)
+
+ self.begin_ambient_camera_rotation(rate=0.24)
+ self.get_region(self.axes,c1,c2)
+ self.play(Write(surface))
+ self.get_lines()
+ self.wait(3.5)
+ self.stop_ambient_camera_rotation()
+ self.wait(.5)
+ self.move_camera(
+ distance=20,
+ phi=10 * DEGREES,
+ theta=80 * DEGREES,
+ run_time=3
+ )
+ self.wait(2)
+
+
+
+ def get_curve(self,axes, func, **kwargs):
+ config = {
+ "t_min": axes.x_min,
+ "t_max": axes.x_max,
+ }
+ config.update(kwargs)
+ return ParametricFunction(
+ lambda x : axes.c2p(
+ x, func(x),0
+ ),
+ **config
+ )
+
+ def get_region(self,axes,curve1,curve2,**kwargs):
+ x_vals=np.arange(axes.x_min,axes.x_max,.1)
+ c1_points=[curve1.get_point_from_function(x) for x in x_vals]
+ c2_points=[curve2.get_point_from_function(x) for x in x_vals]
+ c2_points.reverse()
+ points=c1_points+c2_points
+ region=Polygon(*points,
+ stroke_width=0,
+ fill_color=PINK,
+ fill_opacity=.5
+ )
+ R=TextMobject("R").set_color(PINK).scale(2).rotate(180*DEGREES , OUT)
+ R.move_to(region,IN+RIGHT)
+
+ self.play(ShowCreation(region))
+ self.add(R)
+
+ def get_surface(self,axes, func, **kwargs):
+ config = {
+ "u_min": axes.x_max,
+ "u_max": axes.x_min,
+ "v_min": axes.y_max,
+ "v_max": axes.y_min,
+ "resolution": (10,10),
+ }
+
+ config.update(self.default_surface_config)
+ config.update(kwargs)
+ return ParametricSurface(
+ lambda x,y : axes.c2p(
+ x, y, func(x, y)
+ ),
+ **config
+ )
+
+ def get_lines(self):
+ axes = self.axes
+ labels=[axes.x_axis.n2p(axes.a), axes.x_axis.n2p(axes.b), axes.y_axis.n2p(axes.c),
+ axes.y_axis.n2p(axes.d)]
+
+
+ surface_corners=[]
+ for x,y,z in self.region_corners:
+ surface_corners.append([x,y,self.Func(x,y)])
+
+ lines=VGroup()
+ for start , end in zip(surface_corners,
+ self.region_corners):
+ lines.add(self.draw_lines(start,end,"YELLOW"))
+
+ for start , end in zip(labels,
+ self.region_corners):
+ # lines.add(self.draw_lines(start,end,"BLUE"))
+ # print (start,end)
+ pass
+ self.play(ShowCreation(lines))
+
+
+ def draw_lines(self,start,end,color):
+ start=self.axes.c2p(*start)
+ end=self.axes.c2p(*end)
+ line=DashedLine(start,end,color=color)
+
+ return line
+
+ #customize 3D axes
+ def get_three_d_axes(self, include_labels=True, include_numbers=True, **kwargs):
+ config = dict(self.axes_config)
+ config.update(kwargs)
+ axes = ThreeDAxes(**config)
+ axes.set_stroke(width=2)
+
+ if include_numbers:
+ self.add_axes_numbers(axes)
+
+ if include_labels:
+ self.add_axes_labels(axes)
+
+ # Adjust axis orientation
+ axes.x_axis.rotate(
+ 90 * DEGREES, LEFT,
+ about_point=axes.c2p(0, 0, 0),
+ )
+ axes.y_axis.rotate(
+ 90 * DEGREES, UP,
+ about_point=axes.c2p(0, 0, 0),
+ )
+
+ # Add xy-plane
+ input_plane = self.get_surface(
+ axes, lambda x, t: 0
+ )
+ input_plane.set_style(
+ fill_opacity=0.3,
+ fill_color=PINK,
+ stroke_width=.2,
+ stroke_color=WHITE,
+ )
+
+ axes.input_plane = input_plane
+
+ self.region_corners=[
+ input_plane.get_corner(pos) for pos in (DL,DR,UR,UL)]
+
+ return axes
+
+
+ def setup_axes(self):
+ axes = self.get_three_d_axes(include_labels=True)
+ # axes.add(axes.input_plane)
+ axes.scale(1)
+ # axes.center()
+ axes.shift(axes.axes_shift)
+
+ self.add(axes)
+ self.axes = axes
+
+ def add_axes_numbers(self, axes):
+ x_axis = axes.x_axis
+ y_axis = axes.y_axis
+ tex_vals_x = [
+ ("1", axes.b),
+ ]
+ tex_vals_y=[
+ ("1", axes.d)
+ ]
+ x_labels = VGroup()
+ y_labels = VGroup()
+ for tex, val in tex_vals_x:
+ label = TexMobject(tex)
+ label.scale(1)
+ label.next_to(x_axis.n2p(val), DOWN)
+ label.rotate(180 * DEGREES)
+ x_labels.add(label)
+ x_axis.add(x_labels)
+ x_axis.numbers = x_labels
+
+ for tex, val in tex_vals_y:
+ label = TexMobject(tex)
+ label.scale(1)
+ label.next_to(y_axis.n2p(val), LEFT)
+ label.rotate(90 * DEGREES)
+ y_labels.add(label)
+
+ y_axis.add(y_labels)
+ y_axis.numbers = y_labels
+
+ return axes
+
+ def add_axes_labels(self, axes):
+ x_label = TexMobject("x")
+ x_label.next_to(axes.x_axis.get_end(), RIGHT)
+ axes.x_axis.label = x_label
+
+ y_label = TextMobject("y")
+ y_label.rotate(90 * DEGREES, OUT)
+ y_label.next_to(axes.y_axis.get_end(), UP)
+ axes.y_axis.label = y_label
+
+ z_label = TextMobject("z")
+ z_label.rotate(90 * DEGREES, LEFT)
+ z_label.next_to(axes.z_axis.get_zenith(), LEFT)
+ axes.z_axis.label = z_label
+ for axis in axes:
+ axis.add(axis.label)
+ return axes
+
+ #uploaded by Somnath Pandit.FSF2020_Fubini's_Theorem
+
+
+
+
+
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/file3.o_iteration_methods_checkpoint.py b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/file3.o_iteration_methods_checkpoint.py
new file mode 100644
index 0000000..55f91d3
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/file3.o_iteration_methods_checkpoint.py
@@ -0,0 +1,226 @@
+from manimlib.imports import *
+
+class IterationMethods(GraphScene):
+ CONFIG = {
+ "x_min" : 0,
+ "x_max" : 1,
+ "y_min" : 0,
+ "y_max" : 1,
+ "x_tick_frequency" : 1,
+ "y_tick_frequency" : 1,
+ "x_labeled_nums": list(np.arange(0,2)),
+ "y_labeled_nums": list(np.arange(0 ,2)),
+ "x_axis_width": 6,
+ "y_axis_height": 6,
+ "graph_origin": ORIGIN+4*LEFT+3*DOWN,
+ "area_color": PINK ,
+ "area_opacity": .6,
+ }
+
+ def construct(self):
+ X = RIGHT*self.x_axis_width/(self.x_max- self.x_min)
+ Y = UP*self.y_axis_height/(self.y_max- self.y_min)
+
+ # self.intro_scene()
+ self.setup_axes(animate=True)
+
+
+ curve1= self.get_graph(
+ lambda x : x**2 ,
+ x_min = 0,
+ x_max = 1,
+ color = ORANGE)
+ c1_eqn=self.get_graph_label(
+ curve1,
+ label="y=x^2",
+ x_val=.5,
+ direction=RIGHT,
+ buff=MED_LARGE_BUFF,
+ color=ORANGE,
+ )
+
+ curve2= self.get_graph(
+ lambda x : x ,
+ x_min = 0,
+ x_max = 1,
+ color = YELLOW)
+ c2_eqn=self.get_graph_label(
+ curve2,
+ label="y=x",
+ x_val=.5,
+ direction=LEFT,
+ buff=MED_LARGE_BUFF,
+ color=YELLOW,
+ )
+ self.curve1=curve1
+ self.curve2=curve2
+
+ caption_y_int=TextMobject(r"Observe the limits\\ of integration").to_corner(UR)
+ int_lim=TextMobject(
+ "$$\\int_0^1$$"
+ ).next_to(
+ caption_y_int,DOWN,buff=.5
+ ).align_to(
+ caption_y_int,LEFT
+ )
+
+ self.play(ShowCreation(VGroup(curve1,curve2)),Write(VGroup(c2_eqn,c1_eqn)))
+ rects=self.get_rects()
+
+ self.play(Write(caption_y_int))
+ self.show_integral_values_at_different_x()
+ self.wait(1)
+ self.add(int_lim)
+ self.play(FadeOut(self.brace_group))
+ self.play(ApplyMethod(
+ self.y_int.next_to,
+ int_lim,RIGHT,buff=0))
+
+ self.play(ApplyMethod(
+ self.dx_label.next_to,
+ self.y_int,RIGHT))
+
+ self.show_area()
+
+ self.wait(2)
+
+ ###################
+ def intro_scene(self):
+ text=TextMobject(r"How different orders of \textbf{iterated integral}\\ works over the same region ?" )
+ self.play(Write(text),run_time=4)
+ self.wait(2)
+ self.play(FadeOut(text))
+
+
+ def show_area(self):
+ area = self.bounded_riemann_rectangles(
+ self.curve1,
+ self.curve2,
+ x_min = 0,
+ x_max = 1,
+ dx =.001,
+ start_color = self.area_color,
+ end_color = self.area_color,
+ fill_opacity = 1,
+ stroke_width = 0,
+ )
+ self.play(ShowCreation(area))
+ # self.transform_between_riemann_rects(self.rects,area)
+ self.area = area
+
+ def get_rects(self):
+ rects = self.bounded_riemann_rectangles(
+ self.curve1,
+ self.curve2,
+ x_min = 0,
+ x_max = 1,
+ dx =.01,
+ start_color = self.area_color,
+ end_color = self.area_color,
+ fill_opacity =self.area_opacity,
+ stroke_width = 0,
+ )
+ # self.transform_between_riemann_rects(self.area,rects)
+ self.rects=rects
+ return rects
+
+ def show_integral_values_at_different_x(self):
+ rects=self.rects
+ rect = rects[len(rects)*1//10]
+ dx_brace = Brace(rect, DOWN, buff = 0)
+ dx_label = dx_brace.get_text("$dx$", buff = SMALL_BUFF)
+ dx_brace_group = VGroup(dx_brace,dx_label)
+ rp=int(len(rects)/10)
+ rects_subset = self.rects[4*rp:5*rp]
+
+ last_rect = None
+ for rect in rects_subset:
+ brace = Brace(rect, LEFT, buff =.1)
+ y_int = TexMobject("\\int_{x^2}^{x}dy")#.rotate(PI/2)
+ y_int.next_to(brace, LEFT, MED_SMALL_BUFF)
+ anims = [
+ rect.set_fill, self.area_color, 1,
+ dx_brace_group.next_to, rect, DOWN, SMALL_BUFF
+ ]
+ if last_rect is not None:
+ anims += [
+ last_rect.set_fill, None, 0,
+ # last_rect.set_fill, self.area_color, self.area_opacity,
+ ReplacementTransform(last_brace, brace),
+ ReplacementTransform(last_y_int, y_int),
+ ]
+ else:
+ anims += [
+ GrowFromCenter(brace),
+ Write(y_int)
+ ]
+ self.play(*anims)
+ # self.wait(.2)
+
+ last_rect = rect
+ last_brace = brace
+ last_y_int = y_int
+
+ y_int = last_y_int
+ y_brace = last_brace
+ self.brace_group=VGroup(y_brace,dx_brace,rect)
+ self.y_int=y_int
+ self.dx_label=dx_label
+
+
+ def bounded_riemann_rectangles(
+ self,
+ graph1,
+ graph2,
+ x_min=None,
+ x_max=None,
+ dx=0.01,
+ input_sample_type="center",
+ stroke_width=1,
+ stroke_color=BLACK,
+ fill_opacity=1,
+ start_color=None,
+ end_color=None,
+ show_signed_area=True,
+ width_scale_factor=1.001
+ ):
+ x_min = x_min if x_min is not None else self.x_min
+ x_max = x_max if x_max is not None else self.x_max
+ if start_color is None:
+ start_color = self.default_riemann_start_color
+ if end_color is None:
+ end_color = self.default_riemann_end_color
+ rectangles = VGroup()
+ x_range = np.arange(x_min, x_max, dx)
+ colors = color_gradient([start_color, end_color], len(x_range))
+ for x, color in zip(x_range, colors):
+ if input_sample_type == "left":
+ sample_input = x
+ elif input_sample_type == "right":
+ sample_input = x + dx
+ elif input_sample_type == "center":
+ sample_input = x + 0.5 * dx
+ else:
+ raise Exception("Invalid input sample type")
+ graph1_point = self.input_to_graph_point(sample_input, graph1)
+ graph1_point_dx= self.input_to_graph_point(sample_input + width_scale_factor * dx, graph1)
+ graph2_point = self.input_to_graph_point(sample_input, graph2)
+
+ points = VGroup(*list(map(VectorizedPoint, [
+ graph1_point,
+ graph1_point_dx,
+ graph2_point
+ ])))
+
+ rect = Rectangle()
+ rect.replace(points, stretch=True)
+ if graph1_point[1] < self.graph_origin[1] and show_signed_area:
+ fill_color = invert_color(color)
+ else:
+ fill_color = color
+ rect.set_fill(fill_color, opacity=fill_opacity)
+ rect.set_stroke(stroke_color, width=stroke_width)
+ rectangles.add(rect)
+ return rectangles
+
+#uploaded by Somnath Pandit.FSF2020_Fubini's_Theorem
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/file3_iteration_methods.py b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/file3_iteration_methods.py
new file mode 100644
index 0000000..ad78a0b
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/file3_iteration_methods.py
@@ -0,0 +1,429 @@
+from manimlib.imports import *
+
+class IterationMethods(GraphScene):
+ CONFIG = {
+ "x_min" : 0,
+ "x_max" : 1,
+ "y_min" : 0,
+ "y_max" : 1,
+ "x_tick_frequency" : 1,
+ "y_tick_frequency" : 1,
+ "x_labeled_nums": list(np.arange(0,2)),
+ "y_labeled_nums": list(np.arange(0 ,2)),
+ "x_axis_width": 6,
+ "y_axis_height": 6,
+ "graph_origin": ORIGIN+4.5*LEFT+3*DOWN,
+ "area_color": PINK ,
+ "area_opacity": .6,
+ }
+
+ def construct(self):
+ X = RIGHT*self.x_axis_width/(self.x_max- self.x_min)
+ Y = UP*self.y_axis_height/(self.y_max- self.y_min)
+
+ self.intro_scene()
+ self.setup_axes(animate=True)
+
+
+ curve1= self.get_graph(
+ lambda x : x**2 ,
+ x_min = 0,
+ x_max = 1,
+ color = ORANGE)
+ c1_eqn=self.get_graph_label(
+ curve1,
+ label="y=x^2",
+ x_val=.5,
+ direction=RIGHT,
+ buff=MED_LARGE_BUFF,
+ color=ORANGE,
+ )
+
+ curve2= self.get_graph(
+ lambda x : x ,
+ x_min = 0,
+ x_max = 1,
+ color = YELLOW)
+ c2_eqn=self.get_graph_label(
+ curve2,
+ label="y=x",
+ x_val=.7,
+ direction=LEFT,
+ buff=MED_LARGE_BUFF,
+ color=YELLOW,
+ )
+ self.curve1=curve1
+ self.curve2=curve2
+
+ caption_limit=TextMobject(r"Observe the limits\\ of integration").to_corner(UR)
+ int_lim=TextMobject(
+ "$$\\int_0^1$$"
+ ).next_to(
+ caption_limit,DOWN,buff=.5
+ ).align_to(
+ caption_limit,LEFT
+ )
+ self.int_lim=int_lim
+ self.play(ShowCreation(VGroup(curve1,curve2)),Write(VGroup(c2_eqn,c1_eqn)))
+
+ self.play(Write(caption_limit))
+ self.get_rects()
+ self.show_integral_values_at_different_x()
+ self.wait(1)
+ self.integral_setup(int_lim,first_y=True)
+
+
+ self.another_method_scene()
+ self.remove(self.area)
+ self.wait()
+
+ c1_eqn_y=self.get_graph_label(
+ curve1,
+ label="x=\sqrt y",
+ x_val=.6,
+ direction=RIGHT,
+ buff=MED_LARGE_BUFF,
+ color=ORANGE,
+ )
+ c2_eqn_y=self.get_graph_label(
+ curve2,
+ label="x=y",
+ x_val=.7,
+ direction=LEFT,
+ buff=MED_LARGE_BUFF,
+ color=YELLOW,
+ )
+ self.play(
+ ReplacementTransform(c1_eqn,c1_eqn_y),
+ ReplacementTransform(c2_eqn,c2_eqn_y)
+ )
+ self.get_rects(base_y=True)
+ self.show_integral_values_at_different_y()
+ self.wait(1)
+
+ int_lim_y=int_lim.copy()
+ int_lim_y.next_to(int_lim,DOWN)
+ self.int_lim_y=int_lim_y
+ equal=TextMobject("$$=$$").next_to(int_lim_y,LEFT)
+ self.add(equal)
+
+ self.integral_setup(int_lim_y,first_y=False)
+
+ self.wait(2)
+
+ ###################
+ def intro_scene(self):
+ text=TextMobject(r"How different orders of \textbf{iterated integral}\\ works over the same region ?" )
+ self.play(Write(text),run_time=4)
+ self.wait(2)
+ self.play(FadeOut(text))
+
+ def another_method_scene(self):
+ text=TextMobject(r"The other method\\ of iteration")
+ text.next_to(self.curve1,UP,buff=-1)
+ self.play(GrowFromCenter(text))
+ self.wait(2)
+ self.play(LaggedStart(FadeOut(text),lag_ratio=2))
+
+ def integral_setup(self,ref_object,first_y=True):
+ if first_y:
+ area=self.get_area()
+ self.area=area
+ self.play(FadeOut(self.brace_group))
+ self.play(ApplyMethod(
+ self.y_int.next_to,
+ ref_object,RIGHT,buff=0)
+ )
+
+ self.play(ApplyMethod(
+ self.dx_label.next_to,
+ self.y_int,RIGHT),
+ ShowCreation(area),
+ Write(self.int_lim),run_time=4
+ )
+ else:
+ area=self.get_area(base_y=True)
+ self.area=area
+ self.play(
+ FadeOut(self.y_brace_group),
+ Rotate(self.x_int,PI/2)
+ )
+ self.play(ApplyMethod(
+ self.x_int.next_to,
+ ref_object,RIGHT,buff=0)
+ )
+ self.play(ApplyMethod(
+ self.dy_label.next_to,
+ self.x_int,RIGHT),
+ ShowCreation(area),
+ Write(self.int_lim_y),run_time=4
+ )
+
+ def get_area(self,base_y=False):
+ if base_y:
+ area = self.bounded_riemann_rectangles_y(
+ lambda x: x,
+ lambda x: np.sqrt(x),
+ y_min = 0,
+ y_max = 1,
+ dy =.001,
+ start_color = self.area_color,
+ end_color = self.area_color,
+ fill_opacity =self.area_opacity,
+ stroke_width = 0,
+ )
+ self.y_area = area
+ else:
+ area = self.bounded_riemann_rectangles(
+ self.curve1,
+ self.curve2,
+ x_min = 0,
+ x_max = 1,
+ dx =.001,
+ start_color = self.area_color,
+ end_color = self.area_color,
+ fill_opacity =self.area_opacity,
+ stroke_width = 0,
+ )
+ self.area = area
+
+ # self.transform_between_riemann_rects(self.rects,area)
+ return area
+
+ def get_rects(self,base_y=False):
+ if base_y:
+ rects = self.bounded_riemann_rectangles_y(
+ lambda x: x,
+ lambda x: np.sqrt(x),
+ y_min = 0,
+ y_max = 1,
+ dy =.01,
+ start_color = self.area_color,
+ end_color = self.area_color,
+ fill_opacity =self.area_opacity,
+ stroke_width = 0,
+ )
+ self.y_rects=rects
+ else:
+ rects = self.bounded_riemann_rectangles(
+ self.curve1,
+ self.curve2,
+ x_min = 0,
+ x_max = 1,
+ dx =.01,
+ start_color = self.area_color,
+ end_color = self.area_color,
+ fill_opacity =self.area_opacity,
+ stroke_width = 0,
+ )
+ self.rects=rects
+ # self.transform_between_riemann_rects(self.area,rects)
+
+ return rects
+
+ def show_integral_values_at_different_x(self):
+ rects=self.rects
+ rect = rects[len(rects)*1//10]
+ dx_brace = Brace(rect, DOWN, buff = 0)
+ dx_label = dx_brace.get_text("$dx$", buff = SMALL_BUFF)
+ dx_brace_group = VGroup(dx_brace,dx_label)
+ rp=int(len(rects)/20)
+ rects_subset = rects[6*rp:7*rp]
+
+ last_rect = None
+ for rect in rects_subset:
+ brace = Brace(rect, LEFT, buff =.1)
+ y_int = TexMobject("\\int_{x^2}^{x}dy")#.rotate(PI/2)
+ y_int.next_to(brace, LEFT, MED_SMALL_BUFF)
+ anims = [
+ rect.set_fill, self.area_color, 1,
+ dx_brace_group.next_to, rect, DOWN, SMALL_BUFF
+ ]
+ if last_rect is not None:
+ anims += [
+ last_rect.set_fill, None, 0,
+ # last_rect.set_fill, self.area_color, self.area_opacity,
+ ReplacementTransform(last_brace, brace),
+ ReplacementTransform(last_y_int, y_int),
+ ]
+ else:
+ anims += [
+ GrowFromCenter(brace),
+ Write(y_int)
+ ]
+ self.play(*anims)
+ # self.wait(.2)
+
+ last_rect = rect
+ last_brace = brace
+ last_y_int = y_int
+
+ y_int = last_y_int
+ y_brace = last_brace
+ self.brace_group=VGroup(y_brace,dx_brace,rect)
+ self.y_int=y_int
+ self.dx_label=dx_label
+
+ def show_integral_values_at_different_y(self):
+ rects=self.y_rects
+ rect = rects[len(rects)*1//10]
+ dy_brace = Brace(rect, LEFT, buff = 0)
+ dy_label = dy_brace.get_text("$dy$", buff = SMALL_BUFF)
+ dy_brace_group = VGroup(dy_brace,dy_label)
+ rp=int(len(rects)/20)
+ rects_subset = rects[5*rp:6*rp]
+
+ last_rect = None
+ for rect in rects_subset:
+ brace = Brace(rect, DOWN, buff =.1)
+ x_int = TexMobject("\\int_{y}^{\sqrt y}dx").rotate(-PI/2)
+ x_int.next_to(brace, DOWN, SMALL_BUFF)
+ anims = [
+ rect.set_fill, self.area_color, 1,
+ dy_brace_group.next_to, rect, LEFT, SMALL_BUFF
+ ]
+ if last_rect is not None:
+ anims += [
+ last_rect.set_fill, None, 0,
+ # last_rect.set_fill, self.area_color, self.area_opacity,
+ ReplacementTransform(last_brace, brace),
+ ReplacementTransform(last_x_int, x_int),
+ ]
+ else:
+ anims += [
+ GrowFromCenter(brace),
+ Write(x_int)
+ ]
+ self.play(*anims)
+ # self.wait(.2)
+
+ last_rect = rect
+ last_brace = brace
+ last_x_int = x_int
+
+ x_int = last_x_int
+ y_brace = last_brace
+ self.y_brace_group=VGroup(y_brace,dy_brace,rect)
+ self.x_int=x_int
+ self.dy_label=dy_label
+
+
+ def bounded_riemann_rectangles(
+ self,
+ graph1,
+ graph2,
+ x_min=None,
+ x_max=None,
+ dx=0.01,
+ input_sample_type="center",
+ stroke_width=1,
+ stroke_color=BLACK,
+ fill_opacity=1,
+ start_color=None,
+ end_color=None,
+ show_signed_area=True,
+ width_scale_factor=1.001
+ ):
+ x_min = x_min if x_min is not None else self.x_min
+ x_max = x_max if x_max is not None else self.x_max
+ if start_color is None:
+ start_color = self.default_riemann_start_color
+ if end_color is None:
+ end_color = self.default_riemann_end_color
+ rectangles = VGroup()
+ x_range = np.arange(x_min, x_max, dx)
+ colors = color_gradient([start_color, end_color], len(x_range))
+ for x, color in zip(x_range, colors):
+ if input_sample_type == "left":
+ sample_input = x
+ elif input_sample_type == "right":
+ sample_input = x + dx
+ elif input_sample_type == "center":
+ sample_input = x + 0.5 * dx
+ else:
+ raise Exception("Invalid input sample type")
+ graph1_point = self.input_to_graph_point(sample_input, graph1)
+ graph1_point_dx= self.input_to_graph_point(sample_input + width_scale_factor * dx, graph1)
+ graph2_point = self.input_to_graph_point(sample_input, graph2)
+
+ points = VGroup(*list(map(VectorizedPoint, [
+ graph1_point,
+ graph1_point_dx,
+ graph2_point
+ ])))
+
+ rect = Rectangle()
+ rect.replace(points, stretch=True)
+ if graph1_point[1] < self.graph_origin[1] and show_signed_area:
+ fill_color = invert_color(color)
+ else:
+ fill_color = color
+ rect.set_fill(fill_color, opacity=fill_opacity)
+ rect.set_stroke(stroke_color, width=stroke_width)
+ rectangles.add(rect)
+ return rectangles
+
+ def bounded_riemann_rectangles_y(
+ self,
+ graph1,
+ graph2,
+ y_min=None,
+ y_max=None,
+ dy=0.01,
+ input_sample_type="center",
+ stroke_width=1,
+ stroke_color=BLACK,
+ fill_opacity=1,
+ start_color=None,
+ end_color=None,
+ show_signed_area=True,
+ width_scale_factor=1.001
+ ):
+ y_min = y_min if y_min is not None else self.y_min
+ y_max = y_max if y_max is not None else self.y_max
+ if start_color is None:
+ start_color = self.default_riemann_start_color
+ if end_color is None:
+ end_color = self.default_riemann_end_color
+ rectangles = VGroup()
+ y_range = np.arange(y_min, y_max, dy)
+ colors = color_gradient([start_color, end_color], len(y_range))
+ for y, color in zip(y_range, colors):
+ if input_sample_type == "left":
+ sample_input = y
+ elif input_sample_type == "right":
+ sample_input = y + dy
+ elif input_sample_type == "center":
+ sample_input = y + 0.5 * dy
+ else:
+ raise Exception("Invalid input sample type")
+ graph1_point = self.coords_to_point(
+ graph1(sample_input),sample_input
+ )
+ dy_input=sample_input + width_scale_factor * dy
+ graph1_point_dy= self.coords_to_point(
+ graph1(dy_input),dy_input
+ )
+ graph2_point = self.coords_to_point(
+ graph2(sample_input),sample_input
+ )
+
+ points = VGroup(*list(map(VectorizedPoint, [
+ graph1_point,
+ graph1_point_dy,
+ graph2_point
+ ])))
+
+ rect = Rectangle()
+ rect.replace(points, stretch=True)
+ if graph1_point[1] < self.graph_origin[1] and show_signed_area:
+ fill_color = invert_color(color)
+ else:
+ fill_color = color
+ rect.set_fill(fill_color, opacity=fill_opacity)
+ rect.set_stroke(stroke_color, width=stroke_width)
+ rectangles.add(rect)
+ return rectangles
+
+
+#uploaded by Somnath Pandit.FSF2020_Fubini's_Theorem
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/file4_curvy_region.py b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/file4_curvy_region.py
new file mode 100644
index 0000000..46134a7
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/file4_curvy_region.py
@@ -0,0 +1,102 @@
+from manimlib.imports import *
+
+class CurvyRegion(GraphScene):
+ CONFIG = {
+ "x_min": 0,
+ "x_max": 8,
+ "y_min": 0,
+ "y_max": 6,
+ "graph_origin": ORIGIN+4.5*LEFT+3*DOWN,
+ "x_labeled_nums": np.arange(0, 9,2),
+ "y_labeled_nums": np.arange(0, 7,2),
+ "x_axis_width": 6,
+ "y_axis_height": 6,
+ }
+
+ def construct(self):
+ XD = self.x_axis_width/(self.x_max- self.x_min)
+ YD = self.y_axis_height/(self.y_max- self.y_min)
+ self.X=XD*RIGHT ;self.Y=YD*UP
+
+ sin_curve_points=[self.graph_origin+(2+.5*np.sin(2*y),y,0)
+ for y in np.arange(1,5,.005)]
+
+ cos_curve_points=[self.graph_origin+(
+ 5+.5*np.cos(2*y),y,0)
+ for y in np.arange(1,5,.005)]
+ cos_curve_points.reverse()
+
+ region=Polygon(
+ *sin_curve_points+cos_curve_points,
+ color=YELLOW,
+ stroke_width=1,
+ fill_color=BLUE_E,
+ fill_opacity=.75
+ )
+
+ line=Line((1,0,0),(1,6,0),color=RED)
+ line.move_to(self.graph_origin+2.5*self.X,DOWN)
+ self.line=line
+ self.setup_axes(animate = False)
+
+ self.add(region)
+ self.wait()
+ self.first_y_int_scene()
+ self.try_x_first_scene()
+
+
+ def first_y_int_scene(self):
+ talk=TextMobject(r"For doing the $y$ integration\\ first we need to set\\ proper $y$ limts").to_corner(UR,buff=LARGE_BUFF)
+ problem=TextMobject(r"But here we get\\ more than two $y$ values\\ for a single $x$ value" ).to_corner(UR,buff=LARGE_BUFF)
+ int_y=TextMobject("$$\\int_?^? dy$$").next_to(problem,DOWN,buff=.5)
+
+ self.play(Write(talk))
+ self.play(FadeIn(self.line))
+ self.wait(2)
+ self.play(ReplacementTransform(talk,problem))
+ self.play(
+ ApplyMethod(self.line.shift,3.7*self.X),
+ run_time=4
+ )
+ self.wait()
+ self.play(Write(int_y))
+ self.wait(3)
+ self.play(FadeOut(VGroup(problem,int_y,self.line)))
+
+ def try_x_first_scene(self):
+ try_text=TextMobject(r"But if we try to integrate\\ along $x$ first ...." ).to_corner(UR,buff=LARGE_BUFF)
+ good_limits=TextMobject(r"For one $y$ value we get\\ only \textbf{two} $x$ values $\dots$").to_corner(UR,buff=LARGE_BUFF)
+ limit_values= TextMobject(r"one Lower limit\\ one Upper limit ").next_to(good_limits,DOWN,buff=.5)
+ int_x=TextMobject("$$\\int_{f(y)}^{g(y)} dx$$").next_to(limit_values,DOWN)
+
+ self.setup_line()
+ self.play(Write(try_text))
+ self.play(FadeIn(self.line))
+ self.wait()
+ self.play(ReplacementTransform(try_text,good_limits))
+ self.wait()
+ self.play(
+ ApplyMethod(self.line.shift,3*self.Y),
+ run_time=4
+ )
+ self.play(Write(limit_values))
+ self.wait()
+ self.show_functions()
+ self.play(Write(int_x))
+ self.wait(3)
+
+ def setup_line(self):
+ line=self.line.rotate(PI/2)
+ line.move_to(self.graph_origin+.5*self.X+1.5*self.Y,LEFT)
+ self.line=line
+
+ def show_functions(self):
+ fy=TextMobject("$$f(y)$$")
+ gy=TextMobject("$$g(y)$$")
+ fy.move_to(self.graph_origin+2*self.X+3.3*self.Y)
+ gy.move_to(self.graph_origin+7*self.X+2*self.Y)
+ self.play(FadeIn(VGroup(fy,gy)))
+
+
+ #uploaded by Somnath Pandit.FSF2020_Fubini's_Theorem
+
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/gifs/file1_surface1.gif b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/gifs/file1_surface1.gif
new file mode 100644
index 0000000..8c9fa0a
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/gifs/file1_surface1.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/gifs/file2_surface2.gif b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/gifs/file2_surface2.gif
new file mode 100644
index 0000000..37c4b1d
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/gifs/file2_surface2.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/gifs/file3.o_iteration_methods_checkpoint.gif b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/gifs/file3.o_iteration_methods_checkpoint.gif
new file mode 100644
index 0000000..2e507f9
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/gifs/file3.o_iteration_methods_checkpoint.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/gifs/file3_iteration_methods.gif b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/gifs/file3_iteration_methods.gif
new file mode 100644
index 0000000..4e1611b
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/gifs/file3_iteration_methods.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/gifs/file4_curvy_region.gif b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/gifs/file4_curvy_region.gif
new file mode 100644
index 0000000..b0620e5
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fubini's-theorem/gifs/file4_curvy_region.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fundamental-theorem-of-line-integral/README.md b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fundamental-theorem-of-line-integral/README.md
new file mode 100644
index 0000000..3cdddae
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fundamental-theorem-of-line-integral/README.md
@@ -0,0 +1,9 @@
+**file1_grad_of_scalar_function**
+![file1_grad_of_scalar_function](gifs/file1_grad_of_scalar_function.gif)
+
+**file2_line_int_independent_of_path**
+![file2_line_int_independent_of_path](gifs/file2_line_int_independent_of_path.gif)
+
+**file3_line_int_example**
+![file3_line_int_example](gifs/file3_line_int_example.gif)
+
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fundamental-theorem-of-line-integral/file1_grad_of_scalar_function.py b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fundamental-theorem-of-line-integral/file1_grad_of_scalar_function.py
new file mode 100644
index 0000000..fd3d9b5
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fundamental-theorem-of-line-integral/file1_grad_of_scalar_function.py
@@ -0,0 +1,317 @@
+from manimlib.imports import *
+
+class GradOfScalarFunc(ThreeDScene):
+
+ CONFIG = {
+ "axes_config": {
+ "x_min": -3,
+ "x_max": 3,
+ "y_min": -3,
+ "y_max": 3,
+ "z_min": 0,
+ "z_max": 3,
+ "a":-3 ,"b": 3, "c":-3 , "d":3,
+ "axes_shift": ORIGIN+IN,
+ "x_axis_config": {
+ "tick_frequency": 1,
+ # "include_tip": False,
+ },
+ "y_axis_config": {
+ "tick_frequency": 1,
+ # "include_tip": False,
+ },
+ "z_axis_config": {
+ "tick_frequency": 1,
+ # "include_tip": False,
+ },
+ "num_axis_pieces": 1,
+ },
+ "default_graph_style": {
+ "stroke_width": 5,
+ "stroke_color": WHITE,
+ },
+ "default_vector_field_config": {
+ "delta_x": 1,
+ "delta_y": 1,
+ "x_min": -3,
+ "x_max": 3,
+ "y_min": -3,
+ "y_max": 3,
+ "min_magnitude": 0,
+ "max_magnitude": 3,
+ "colors": [TEAL,GREEN,YELLOW,RED],
+ "length_func": lambda norm : norm*np.exp(-.38*norm)/2,
+ "opacity": 1.0,
+ "vector_config": {
+ "stroke_width":8
+ },
+ },
+ "default_surface_config": {
+ "fill_opacity": 0.5,
+ "checkerboard_colors": [BLUE_E],
+ "stroke_width": .2,
+ "stroke_color": WHITE,
+ "stroke_opacity": 0.5,
+ },
+ }
+
+
+ def construct(self):
+
+ self.setup_axes()
+ axes=self.axes
+
+ self.set_camera_orientation(distance=35,
+ phi=70 * DEGREES,
+ theta=-135 * DEGREES,
+ )
+
+ scalar_fn_text=TexMobject("f(x,y)=","xy").set_color(BLUE)
+ scalar_fn_text.to_corner(UR,buff=.6)
+
+ operator=TexMobject("\\vec\\nabla").next_to(
+ scalar_fn_text,LEFT,buff=.2
+ ).set_color(GOLD)
+
+ grad_text=TexMobject(r"\dfrac{\partial f}{\partial x} \hat i+\dfrac{\partial f}{\partial y} \hat j").set_color(GOLD)
+ grad_text.next_to(scalar_fn_text,DOWN).scale(.9)
+
+ VGroup(
+ grad_text[0][1],
+ grad_text[0][9]
+ ).set_color(BLUE)
+ VGroup(
+ grad_text[0][5:8],
+ grad_text[0][13:16]
+ ).set_color(WHITE)
+
+ vector_field_text=TexMobject("\\vec F=y\hat i+x\hat j").set_color_by_gradient(*self.default_vector_field_config["colors"])
+ vector_field_text.next_to(scalar_fn_text,DOWN)
+
+
+ #always generate the scalar field first
+ s_field1=self.get_scalar_field(
+ func= lambda u ,v : u*v/7
+ )
+ v_field1=self.get_vector_field(
+ lambda v: np.array([
+ v[1],
+ v[0],
+ 0,
+ ]),
+ on_surface=True,
+ )
+
+ self.add_fixed_in_frame_mobjects(scalar_fn_text)
+
+ self.begin_ambient_camera_rotation(rate=.2)
+ self.play(Write(s_field1))
+ self.wait(1)
+ self.stop_ambient_camera_rotation()
+
+ self.add_fixed_in_frame_mobjects(operator)
+ self.play(Write(operator),FadeOut(scalar_fn_text[1]))
+ self.add_fixed_in_frame_mobjects(grad_text)
+ self.play(Write(grad_text))
+ self.wait(2)
+
+
+ show_vects=[
+ FadeIn(v_field1),
+ ]
+
+ self.begin_ambient_camera_rotation(rate=.2)
+ self.move_camera(
+ # distance=20,
+ phi=60 * DEGREES,
+ added_anims=show_vects,
+ run_time=4.5
+ )
+
+ self.play(FadeOut(grad_text))
+ self.wait(2)
+ self.stop_ambient_camera_rotation()
+
+ self.add_fixed_in_frame_mobjects(vector_field_text)
+ vector_field= [
+ FadeOut(s_field1),
+ Write(vector_field_text),
+ ]
+ self.move_camera(
+ # distance=20,
+ phi=0 * DEGREES,
+ theta=-90 * DEGREES,
+ added_anims=vector_field,
+ run_time=2
+ )
+ self.wait(2)
+
+
+
+
+
+ def get_scalar_field(self,func,**kwargs):
+ surface= self.get_surface(
+ lambda x , y:
+ func(x,y),
+ )
+
+ self.surface_points=self.get_points(func)
+ return surface
+
+ def get_points(self,func):
+ axes=self.axes
+ dn=.5
+ x_vals=np.arange(axes.a,axes.b,dn)
+ y_vals=np.arange(axes.c,axes.d,dn)
+ points=[]
+ for x_val in x_vals:
+ for y_val in y_vals:
+ points+=[axes.c2p(x_val,y_val,func(x_val,y_val)+.05)]
+ return points
+
+ def get_vector_field(self,func,on_surface=True,**kwargs):
+ config = dict()
+ config.update(self.default_vector_field_config)
+ config.update(kwargs)
+ vector_field= VectorField(func,**config)
+ vector_field.move_to(self.axes.c2p(0,0,0))
+ self.vector_field=vector_field
+
+ if on_surface:
+ vector_field=self.get_vectors_on_surface()
+
+ return vector_field
+
+
+
+ def get_vectors_on_surface(self):
+ vectors_on_surface = VGroup(*[
+ self.vector_field.get_vector(point)
+ for point in self.surface_points
+ ])
+
+ return vectors_on_surface
+
+
+
+ def get_surface(self, func, **kwargs):
+ axes=self.axes
+ config = {
+ "u_min": axes.a,
+ "u_max": axes.b,
+ "v_min": axes.c,
+ "v_max": axes.d,
+ "resolution": (
+ 2*(axes.y_max - axes.y_min) // axes.y_axis.tick_frequency,
+ (axes.x_max - axes.x_min) // axes.x_axis.tick_frequency,
+ ),
+ }
+
+ config.update(self.default_surface_config)
+ config.update(kwargs)
+ return ParametricSurface(
+ lambda x,y : axes.c2p(
+ x, y, func(x, y)
+ ),
+ **config
+ )
+
+
+
+#-------------------------------------------------------
+ #customize 3D axes
+ def get_three_d_axes(self, include_labels=True, include_numbers=False, **kwargs):
+ config = dict(self.axes_config)
+ config.update(kwargs)
+ axes = ThreeDAxes(**config)
+ axes.set_stroke(width=2)
+ self.axes=axes
+
+ if include_numbers:
+ self.add_axes_numbers(axes)
+
+ if include_labels:
+ self.add_axes_labels(axes)
+
+ # Adjust axis orientation
+ axes.x_axis.rotate(
+ -90 * DEGREES, LEFT,
+ about_point=axes.c2p(0, 0, 0),
+ )
+ axes.y_axis.rotate(
+ 90 * DEGREES, UP,
+ about_point=axes.c2p(0, 0, 0),
+ )
+
+ return axes
+
+
+ def setup_axes(self):
+ axes = self.get_three_d_axes(include_labels=True)
+ axes.scale(1)
+ # axes.center()
+ axes.shift(axes.axes_shift)
+
+ self.add(axes)
+ self.axes = axes
+
+ def add_axes_numbers(self, axes):
+ x_axis = axes.x_axis
+ y_axis = axes.y_axis
+ tex_vals_x = [
+
+ ("1", axes.b),
+ ("-1", axes.a),
+ ]
+ tex_vals_y=[
+
+ ("1", axes.d)
+ ]
+ x_labels = VGroup()
+ y_labels = VGroup()
+ for tex, val in tex_vals_x:
+ label = TexMobject(tex)
+ label.scale(1)
+ label.next_to(x_axis.n2p(val), DOWN)
+ # label.rotate(180 * DEGREES)
+ x_labels.add(label)
+ x_axis.add(x_labels)
+ x_axis.numbers = x_labels
+
+ for tex, val in tex_vals_y:
+ label = TexMobject(tex)
+ label.scale(1)
+ label.next_to(y_axis.n2p(val), LEFT)
+ label.rotate(90 * DEGREES)
+ y_labels.add(label)
+
+ y_axis.add(y_labels)
+ y_axis.numbers = y_labels
+
+ return axes
+
+ def add_axes_labels(self, axes):
+ x_label = TexMobject("x")
+ x_label.next_to(axes.x_axis.get_end(), RIGHT)
+ axes.x_axis.label = x_label
+
+ y_label = TextMobject("y")
+ y_label.rotate(90 * DEGREES, OUT)
+ y_label.next_to(axes.y_axis.get_end(), UP)
+ axes.y_axis.label = y_label
+
+ z_label = TextMobject("z")
+ z_label.rotate(90 * DEGREES, RIGHT)
+ z_label.next_to(axes.z_axis.get_zenith(), LEFT)
+ axes.z_axis.label = z_label
+ for axis in axes:
+ axis.add(axis.label)
+ return axes
+
+
+
+ #uploaded by Somnath Pandit. FSF2020_Fundamental_Theorem_of_Line_Integrals
+
+
+
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fundamental-theorem-of-line-integral/file2_line_int_independent_of_path.py b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fundamental-theorem-of-line-integral/file2_line_int_independent_of_path.py
new file mode 100644
index 0000000..b8f7cfa
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fundamental-theorem-of-line-integral/file2_line_int_independent_of_path.py
@@ -0,0 +1,174 @@
+from manimlib.imports import *
+
+
+class LineIntegration(GraphScene):
+ CONFIG = {
+ "x_min" : -5,
+ "x_max" : 5,
+ "y_min" : -5,
+ "y_max" : 5,
+ "axes_color":BLACK,
+ "graph_origin": ORIGIN+1.2*DOWN,
+ "x_axis_width": 10,
+ "y_axis_height": 10 ,
+ "x_axis_label": "",
+ "y_axis_label": "",
+ "x_tick_frequency": 1,
+ "y_tick_frequency": 1,
+ "default_vector_field_config": {
+ "delta_x": .6,
+ "delta_y": .6,
+ "min_magnitude": 0,
+ "max_magnitude": .5,
+ "colors": [GREEN,BLUE,BLUE,TEAL],
+ "length_func": lambda norm : .45*sigmoid(norm),
+ "opacity": .75,
+ "vector_config": {
+ "stroke_width":1.5
+ },
+ },
+
+ "a": .45,"b": 2,
+ "path_color": PURPLE
+ }
+
+ def construct(self):
+ X = RIGHT*self.x_axis_width/(self.x_max- self.x_min)
+ Y = UP*self.y_axis_height/(self.y_max- self.y_min)
+ self.X=X ;self.Y=Y
+
+ self.setup_axes(animate=False)
+
+
+
+
+ vector_field=self.get_vector_field(
+ lambda v: np.array([
+ v[1]-self.graph_origin[1],
+ v[0]-self.graph_origin[0],
+ 0,
+ ])
+ )
+ vector_field_text=TexMobject(
+ "\\vec F(x,y)","=y\hat i+x\hat j",
+ stroke_width=1.5
+ ).to_edge(TOP,buff=.2)
+
+ vector_field_text[0][0:2].set_color(TEAL)
+
+ grad_f=TexMobject(
+ "\\vec\\nabla f(x,y)",
+ stroke_width=1.5
+ )
+ grad_f[0][2].set_color(LIGHT_BROWN)
+ grad_f.move_to(vector_field_text[0])
+
+ self.add(vector_field,)
+ self.play(Write(vector_field_text))
+ self.wait()
+ self.play(
+ ReplacementTransform(
+ vector_field_text[0],grad_f
+ )
+ )
+ self.get_endpoints_of_curve()
+ self.wait(.6)
+ vector_field.set_fill(opacity=.4)
+ self.show_line_integral()
+ self.wait(2)
+
+
+
+
+
+ def get_vector_field(self,func,**kwargs):
+ config = dict()
+ config.update(self.default_vector_field_config)
+ config.update(kwargs)
+ vector_field= VectorField(func,**config)
+
+ self.vector_field= vector_field
+
+ return vector_field
+
+
+
+ def get_endpoints_of_curve(self):
+ points=[[-3,0],[2,2]]
+ point_labels= ["P_f","P_i"]
+ for point,label in zip(points,point_labels):
+ dot=Dot(self.coords_to_point(*point)).set_color(RED)
+ dot_label=TexMobject(label)
+ dot_label.next_to(dot,DR,buff=.2)
+ self.play(FadeIn(VGroup(dot,dot_label)))
+ self.wait(.2)
+
+ self.end_points=points
+
+ def show_line_integral(self):
+ int_text=TexMobject(
+ r"\int_{P_i}^{P_f}\vec F \cdot d\vec r",
+ stroke_width=1.5,
+ ).scale(1.2)
+ int_text[0][0].set_color(self.path_color)
+ int_text[0][5:7].set_color(TEAL)
+ int_text.to_edge(RIGHT+UP,buff=1)
+
+ int_value= TexMobject(r"=f(P_i)-f(P_f)",
+ stroke_width=1.5
+ ).next_to(int_text,DOWN)
+ VGroup(int_value[0][1],
+ int_value[0][7]
+ ).set_color(LIGHT_BROWN)
+
+ path_indepent_text=TextMobject(
+ r"Value of the Line Integral is\\ independent of Path",color=GOLD,stroke_width=2,).to_corner(DR,buff=1)
+
+ path_indepent_text[0][-4:].set_color(self.path_color)
+
+
+ self.play(Write(VGroup(
+ int_text,int_value
+ )),
+ run_time=2
+ )
+ self.wait(1.5)
+
+
+ self.show_path([[0,1],[-1,2],[1,3]])
+ self.play(Indicate(int_value))
+ self.play(Uncreate(self.path))
+
+ self.show_path([[0,1]])
+ self.play(Indicate(int_value))
+ self.play(Uncreate(self.path))
+
+ self.show_path([[-1,1],[-1,-2],[-5,0],[-2,3.5],[1,1]])
+ self.play(Indicate(int_value),run_time=2)
+ self.wait(.6)
+
+ self.play(Write(path_indepent_text))
+
+
+
+ def show_path(self,points):
+ points=[self.end_points[0]]+points+[self.end_points[1]]
+
+ path= VMobject()
+ path.set_points_smoothly([
+ self.coords_to_point(*point)
+ for point in points
+ ])
+ path.set_color(self.path_color)
+ self.play(ShowCreation(path),run_time=1.5)
+
+ self.path=path
+
+
+
+
+
+#uploaded by Somnath Pandit. FSF2020_Fundamental_Theorem_of_Line_Integrals
+
+
+
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fundamental-theorem-of-line-integral/file3_line_int_example.py b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fundamental-theorem-of-line-integral/file3_line_int_example.py
new file mode 100644
index 0000000..71506a3
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fundamental-theorem-of-line-integral/file3_line_int_example.py
@@ -0,0 +1,149 @@
+from manimlib.imports import *
+
+
+class LineIntegration(GraphScene):
+ CONFIG = {
+ "x_min" : -1,
+ "x_max" : 2,
+ "y_min" : -1,
+ "y_max" : 2,
+ "graph_origin": ORIGIN+3*LEFT+1.5*DOWN,
+ "x_axis_width": 10,
+ "y_axis_height": 10 ,
+ "x_tick_frequency": 1,
+ "y_tick_frequency": 1,
+ "default_vector_field_config": {
+ "delta_x": .5,
+ "delta_y": .5,
+ "min_magnitude": 0,
+ "max_magnitude": .5,
+ "colors": [GREEN,BLUE,BLUE,TEAL],
+ "length_func": lambda norm : .4*sigmoid(norm),
+ "opacity": .75,
+ "vector_config": {
+ "stroke_width":2
+ },
+ },
+
+ "a": .45,"b": 2,
+ }
+
+ def construct(self):
+ X = RIGHT*self.x_axis_width/(self.x_max- self.x_min)
+ Y = UP*self.y_axis_height/(self.y_max- self.y_min)
+ self.X=X ;self.Y=Y
+
+ self.setup_axes(animate=False)
+
+
+
+
+ vector_field=self.get_vector_field(
+ lambda v: np.array([
+ v[1]-self.graph_origin[1],
+ v[0]-self.graph_origin[0],
+ 0,
+ ])
+ )
+ vector_field_text=TexMobject(
+ "\\vec F=y\hat i+x\hat j",
+ stroke_width=2
+ ).to_corner(UR,buff=.75).scale(1.2)
+
+ vector_field_text[0][0:3].set_color(TEAL),
+ self.add(vector_field,)
+ self.play(Write(vector_field_text))
+ self.wait()
+ self.get_endpoints_of_curve()
+ self.wait(.6)
+ self.play(
+ vector_field_text.shift,5*LEFT,
+
+ )
+ vector_field.set_fill(opacity=.2)
+ self.show_line_integral()
+ self.wait(2)
+
+
+
+
+
+ def get_vector_field(self,func,**kwargs):
+ config = dict()
+ config.update(self.default_vector_field_config)
+ config.update(kwargs)
+ vector_field= VectorField(func,**config)
+
+ self.vector_field= vector_field
+
+ return vector_field
+
+
+
+ def get_endpoints_of_curve(self):
+ points=[[1,1],[0,0]]
+ point_labels= ["(1,1)","(0,0)"]
+ for point,label in zip(points,point_labels):
+ dot=Dot(self.coords_to_point(*point)).set_color(RED)
+ dot_label=TexMobject(label)
+ dot_label.next_to(dot,DR)
+ self.add(dot,dot_label)
+ self.end_points=points
+
+ def show_line_integral(self):
+ int_text=TexMobject(
+ "\\int_\\text{\\textbf{path}}\\vec F \\cdot d\\vec r= 1",
+ color=BLUE,
+ stroke_width=1.5
+ ).scale(1.2)
+ int_text[0][0].set_color(RED_C)
+ int_text[0][5:7].set_color(TEAL)
+ int_text.to_edge(RIGHT+UP,buff=1)
+
+ close_int=TexMobject("O").set_color(RED).scale(1.3)
+ close_int.move_to(int_text[0][0],OUT)
+ close_int_val=TexMobject("0",color=BLUE).scale(1.4)
+ close_int_val.move_to(int_text[0][-1],OUT)
+
+ self.play(Write(int_text))
+
+
+ self.show_method([[0,1]])
+ self.play(Indicate(int_text))
+ self.wait()
+
+ self.show_method([[1,0]])
+ self.play(Indicate(int_text))
+ self.wait()
+ self.remove(int_text[0][-1])
+ self.add(close_int)
+
+ for i in range(2):
+ self.play(self.paths[i].rotate,PI)
+ self.play(Indicate(close_int))
+ self.play(Write(close_int_val))
+ self.wait()
+
+
+ def show_method(self,points):
+ points=points+self.end_points
+ paths=[]
+ for i in range(-1,len(points)-2):
+ path=Arrow(
+ self.coords_to_point(*points[i]),
+ self.coords_to_point(*points[i+1]),
+ buff=0
+ ).set_color(BLUE)
+ paths+=VGroup(path)
+ self.play(GrowArrow(path),run_time=1.5)
+
+ self.paths=paths
+
+
+
+
+
+#uploaded by Somnath Pandit. FSF2020_Fundamental_Theorem_of_Line_Integrals
+
+
+
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fundamental-theorem-of-line-integral/gifs/file1_grad_of_scalar_function.gif b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fundamental-theorem-of-line-integral/gifs/file1_grad_of_scalar_function.gif
new file mode 100644
index 0000000..1fd2e15
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fundamental-theorem-of-line-integral/gifs/file1_grad_of_scalar_function.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fundamental-theorem-of-line-integral/gifs/file2_line_int_independent_of_path.gif b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fundamental-theorem-of-line-integral/gifs/file2_line_int_independent_of_path.gif
new file mode 100644
index 0000000..8d375bb
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fundamental-theorem-of-line-integral/gifs/file2_line_int_independent_of_path.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fundamental-theorem-of-line-integral/gifs/file3_line_int_example.gif b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fundamental-theorem-of-line-integral/gifs/file3_line_int_example.gif
new file mode 100644
index 0000000..20ed081
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/fundamental-theorem-of-line-integral/gifs/file3_line_int_example.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/README.md b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/README.md
new file mode 100644
index 0000000..7e4299d
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/README.md
@@ -0,0 +1,15 @@
+**file1_scalar_line_int_as_sum**
+![file1_scalar_line_int_as_sum](gifs/file1_scalar_line_int_as_sum.gif)
+
+**file2_scalar_line_integral**
+![file2_scalar_line_integral](gifs/file2_scalar_line_integral.gif)
+
+
+**file3_vector_line_int_as_sum**
+![file3_vector_line_int_as_sum](gifs/file3_vector_line_int_as_sum.gif)
+
+**file4_vector_line_integral**
+![file4_vector_line_integral](gifs/file4_vector_line_integral.gif)
+
+**file5_helix**
+![file5_helix](gifs/file5_helix.gif)
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/file1_scalar_line_int_as_sum.py b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/file1_scalar_line_int_as_sum.py
new file mode 100644
index 0000000..af32ebf
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/file1_scalar_line_int_as_sum.py
@@ -0,0 +1,227 @@
+from manimlib.imports import *
+
+
+class LineIntegrationAsSum(GraphScene):
+ CONFIG = {
+ "x_min" : 0,
+ "x_max" : 10,
+ "y_min" : 0,
+ "y_max" : 6,
+ "graph_origin": ORIGIN+5*LEFT+3*DOWN,
+ "x_axis_width": 10,
+ "y_axis_height": 6 ,
+ "x_tick_frequency": 2,
+ "y_tick_frequency": 2,
+ "Func":lambda x : 1+x**1.3*np.exp(-.12*(x-2)**2)*np.sin(x/4),
+ "a": 1 ,"b": 9, "n": 15,
+ }
+
+ def construct(self):
+ X = RIGHT*self.x_axis_width/(self.x_max- self.x_min)
+ Y = UP*self.y_axis_height/(self.y_max- self.y_min)
+ self.X=X ;self.Y=Y
+
+ self.setup_axes(animate=False)
+
+ curve=self.get_graph(
+ self.Func,
+ x_min=self.a,
+ x_max=self.b,
+ )
+ curve.set_color([BLACK,BLUE,BLUE,BLUE,BLACK])
+ curve_label= self.get_graph_label(
+ curve,
+ label="\\text{path of intgration}",
+ x_val=4,
+ direction=UR,
+ buff=.6,
+ color=BLUE
+ )
+ self.curve=curve
+ self.curve_label=curve_label
+
+ self.play(ShowCreation(VGroup(curve,curve_label)))
+ self.wait(.6)
+ self.break_in_arcs()
+ self.show_the_sum()
+ self.construct_equation()
+ self.wait(2)
+
+
+
+ def break_in_arcs(self):
+
+ self.write_about_breaking()
+
+ dl=0.8
+ self.get_breakers(dl)
+ self.wait(2)
+ self.play(FadeOut(self.upto_break_text))
+ self.dl=dl
+
+ def write_about_breaking(self):
+ breaking_text=TextMobject("\\texttt{..broken}"," into small", "subarcs")
+ breaking_text.set_color_by_tex_to_color_map({
+ "broken":RED,"subarcs": BLUE
+ })
+ breaking_text.next_to(self.curve_label,DOWN)
+ breaking_text.align_to(self.curve_label,LEFT)
+ self.play(
+ Write(breaking_text)
+ )
+
+ self.upto_break_text=VGroup(
+ self.curve_label,
+ breaking_text,
+ )
+
+ def get_breakers(self,dl):
+ point=self.a
+ points=[]
+ while point<(self.b-dl) :
+ start=point
+ end=point+dl
+ points += [end]
+ breaker=Line(
+ self.input_to_graph_point(start,self.curve),
+ self.input_to_graph_point(end,self.curve),
+ stroke_width=2,
+ color=RED,
+ )
+ breaker.rotate(PI/2).scale(.5)
+
+ point=end
+ self.play(FadeIn(breaker),run_time=.2)
+ # self.add(breaker)
+
+ del points[-1]
+ self.points=points
+
+
+ def show_the_sum(self):
+ at_any_points_text=TextMobject("At any ","point", "in each ", "subarc")
+ at_any_points_text.set_color_by_tex_to_color_map({
+ "point":YELLOW , "subarc": BLUE
+ })
+ at_any_points_text.to_edge(TOP,buff=SMALL_BUFF)
+
+ evaluate_text=TextMobject("$f(x,y)$ ", "is evaluated").next_to(at_any_points_text,DOWN)
+ evaluate_text.set_color_by_tex("$f(x,y)$",ORANGE)
+
+ self.at_any_points_text=at_any_points_text
+ self.evaluate_text=evaluate_text
+
+
+ dots=[]
+ for point in self.points:
+
+ dot=Dot(
+ point=self.input_to_graph_point(point,self.curve),
+ radius= .7*DEFAULT_DOT_RADIUS,
+ stroke_width= 0,
+ fill_opacity= 1.0,
+ color= YELLOW,
+ )
+ dots+=[dot]
+
+ self.play(
+ Write(at_any_points_text),
+ FadeIn(VGroup(*dots)),run_time=1.5
+ )
+ self.wait()
+ self.position_of_point_irrelevent()
+ self.multiply_with_function(dots)
+
+
+
+ def multiply_with_function(self,dots):
+ index=-(len(self.points)//3)
+ dot=dots[index]
+
+
+ multiply_text=TexMobject("f(x_i,y_i)", "\\text{ is multiplied with }","\\Delta s_i")
+ multiply_text.set_color_by_tex_to_color_map({
+ "f(x_i,y_i)":ORANGE , "\\Delta s_i": BLUE
+ })
+ multiply_text.to_edge(TOP,buff=MED_SMALL_BUFF)
+
+ point_coord=TextMobject("$(x_i,y_i)$",color=YELLOW)
+ point_coord.next_to(dot,DL,buff=.01).scale(.8)
+
+ func_val=TextMobject("$f(x_i,y_i)$",color=ORANGE)
+ func_val.next_to(dot,UR)
+
+ sum_up_text=TextMobject("and "," summed ", "for all i' s")
+ sum_up_text.set_color_by_tex("summed",PURPLE)
+ sum_up_text.next_to(multiply_text,DOWN)
+
+
+ self.play(FadeIn(VGroup(
+ point_coord,dot
+ )))
+ self.play(Write(self.evaluate_text))
+ self.play(Write(func_val))
+
+ self.wait(2)
+ self.remove(point_coord)
+ self.get_ds(dots,index)
+ self.play(GrowFromCenter(self.ds_brace_group))
+ self.wait(2)
+ self.play(FadeOut(VGroup(
+ self.ds_brace,
+ self.at_any_points_text,
+ self.evaluate_text
+ )))
+ self.play(Write(multiply_text))
+ self.play(ApplyMethod(
+ self.ds_brace_label.next_to,
+ func_val, RIGHT,buff=.2
+ ))
+ self.play(Write(sum_up_text))
+ dot.set_color(ORANGE).scale(1.2)
+ self.play(FadeIn(VGroup(*[
+ dot.set_color(ORANGE).scale(1.4)
+ for dot in dots ]
+ )))
+ self.func_val=func_val
+ self.sum_text_group=VGroup(multiply_text,sum_up_text)
+
+ def position_of_point_irrelevent(self):
+ pass
+
+
+
+ def get_ds(self,dots,index):
+ p1= dots[index]
+ p2= dots[index+1]
+ ds_brace=Brace(VGroup(p1,p2),DL)
+ ds_brace.move_to(p1,UR)
+ ds_brace_label=ds_brace.get_text("$\Delta s_i$", buff = .05)
+ ds_brace_label.set_color(BLUE)
+ self.ds_brace=ds_brace
+ self.ds_brace_label=ds_brace_label
+ self.ds_brace_group=VGroup(ds_brace,ds_brace_label)
+
+
+ def construct_equation(self):
+ sum_eqn=TextMobject("$$\\sum_i^{ } $$").set_color(PURPLE)
+ sum_eqn.move_to(self.graph_origin+7*self.X+4*self.Y)
+
+ line_integral_text=TextMobject("The Value of the line integral is").next_to(self.sum_text_group,IN)
+ approx=TextMobject("$\\approx$",color=RED).next_to(sum_eqn,LEFT)
+ multipled=VGroup(self.func_val,self.ds_brace_label)
+ self.play(FadeIn(sum_eqn))
+ self.play(ApplyMethod(
+ multipled.next_to,sum_eqn,RIGHT
+ ))
+ self.wait()
+ self.play(FadeOut(self.sum_text_group))
+ self.play(Write(line_integral_text))
+ self.play(FadeIn(approx))
+
+
+
+#uploaded by Somnath Pandit.FSF2020_Line Integrals
+
+
+
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/file2_scalar_line_integral.py b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/file2_scalar_line_integral.py
new file mode 100644
index 0000000..200f768
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/file2_scalar_line_integral.py
@@ -0,0 +1,427 @@
+from manimlib.imports import *
+
+class LineIntegrationProcess(SpecialThreeDScene):
+
+ CONFIG = {
+ "axes_config": {
+ "x_min": -4,
+ "x_max": 4,
+ "y_min": 0,
+ "y_max": 4,
+ "z_min": 0,
+ "z_max": 4,
+ "a":-3 ,"b": 3, "c":0 , "d":3.5,
+ "axes_shift":3*IN,
+ "x_axis_config": {
+ "tick_frequency": 1,
+ # "include_tip": False,
+ },
+ "y_axis_config": {
+ "tick_frequency": 1,
+ # "include_tip": False,
+ },
+ "z_axis_config": {
+ "tick_frequency": 1,
+ # "include_tip": False,
+ },
+ "num_axis_pieces": 1,
+ },
+ "default_graph_style": {
+ "stroke_width": 2,
+ "stroke_color": WHITE,
+ },
+ "default_surface_config": {
+ "fill_opacity": 0.5,
+ "checkerboard_colors": [LIGHT_GREY],
+ "stroke_width": 0.2,
+ "stroke_color": WHITE,
+ "stroke_opacity": 0.75,
+ },
+ "Func": lambda x,y: 1+x**2*y/15
+ }
+
+
+ def construct(self):
+
+ self.setup_axes()
+ axes=self.axes
+
+ self.set_camera_orientation(distance=35,
+ phi=60 * DEGREES,
+ theta=-60 * DEGREES,
+ )
+
+ fn_text=TextMobject("$z=2+x^2y$").set_color(BLUE)
+ fn_text.to_corner(UR,buff=.8).shift(DOWN)
+
+ #get the surface
+ surface= self.get_surface(
+ lambda x , y:
+ self.Func(x,y)
+ )
+ surface.set_style(
+ fill_opacity=0.5,
+ fill_color=BLUE_D,
+ stroke_width=0.5,
+ stroke_color=WHITE,
+ )
+
+
+ # self.play(Write(surface))
+ self.add_fixed_in_frame_mobjects(fn_text)
+ self.play(Write(surface),Write(fn_text))
+ self.get_line_of_int()
+ self.begin_ambient_camera_rotation(rate=-0.035)
+ self.get_field_values_on_line()
+ self.wait(1.5)
+ self.area=self.get_area()
+ area_text=TextMobject("Line"," Integral in the",r" scalar field\\"," means this" ,"area")
+ area_text.set_color_by_tex_to_color_map({
+ "Line": PINK, "scalar":BLUE, "area":TEAL_A
+ })
+ area_text.to_edge(TOP,buff=MED_SMALL_BUFF)
+
+ self.remove(self.values_on_line_text)
+ self.add_fixed_in_frame_mobjects(area_text)
+ self.play(Write(area_text))
+ self.play(Write(self.area),run_time=2)
+ self.play(FadeOut(VGroup(surface,fn_text)))
+ self.move_camera(
+ # distance=20,
+ phi=90 * DEGREES,
+ # theta=-90 * DEGREES,
+ # added_anims=into_graph,
+ run_time=2
+ )
+ self.wait(2)
+
+ self.stop_ambient_camera_rotation()
+ # self.get_lines()
+
+ self.remove(axes,surface)
+ self.trasform_to_graphs()
+ self.wait(2)
+
+
+
+
+ def get_line_of_int(self):
+ line_of_int_text=TextMobject(r"Line of integration is\\","$\\vec r(t)=\cos(t)\hat x+\sin(t)\hat y$")
+ line_of_int_text[1].set_color(PINK)
+ line_of_int_text.to_edge(TOP,buff=SMALL_BUFF)
+
+
+ line_of_int=(self.get_curve(
+ self.Func,on_surface=False
+ ))
+ line_of_int.set_style(
+ stroke_width=5,
+ stroke_color=PINK,
+ )
+
+ self.add_fixed_in_frame_mobjects(line_of_int_text)
+ self.play(Write(line_of_int_text))
+ self.wait()
+ self.play(ShowCreation(line_of_int),run_time=3)
+ # self.add(line_of_int)
+
+ self.line_of_int=line_of_int
+ self.line_of_int_text=line_of_int_text
+
+ def get_field_values_on_line(self):
+ self.remove(self.line_of_int_text)
+
+ values_on_line_text=TextMobject("Values"," of"," function","on the ","line")
+ values_on_line_text.set_color_by_tex_to_color_map({
+ "Values":YELLOW, "function":BLUE,"line":PINK
+ })
+ values_on_line_text.to_edge(TOP,buff=SMALL_BUFF)
+
+ values_on_surface=(self.get_curve(
+ self.Func,on_surface=True
+ ))
+ values_on_surface.set_style(
+ stroke_width=5,
+ stroke_color=YELLOW,
+ )
+
+ self.add_fixed_in_frame_mobjects(values_on_line_text)
+ self.play(Write(values_on_line_text))
+ # self.wait()
+ self.play(ShowCreation(values_on_surface),run_time=3)
+ # self.add(values_on_surface)
+
+ self.values_on_surface=values_on_surface
+ self.values_on_line_text=values_on_line_text
+
+
+ def trasform_to_graphs(self):
+ on_surface_graph=(self.get_graph(
+ self.Func,on_surface=True
+ ))
+ on_surface_graph.set_style(
+ stroke_width=5,
+ stroke_color=YELLOW,
+ )
+
+ line_graph=(self.get_graph(
+ self.Func,on_surface=False
+ ))
+ line_graph.set_style(
+ stroke_width=5,
+ stroke_color=PINK,
+ )
+
+ self.on_surface_graph=on_surface_graph
+ self.line_graph=line_graph
+ graph_area=self.get_area(graph=True)
+
+ into_graph=[
+ ReplacementTransform(
+ self.values_on_surface,
+ on_surface_graph
+ ),
+ ReplacementTransform(
+ self.line_of_int,
+ line_graph
+ ),
+ ReplacementTransform(
+ self.area,
+ graph_area
+ ),
+ ]
+
+ self.move_camera(
+ # distance=20,
+ phi=90 * DEGREES,
+ theta=-90 * DEGREES,
+ added_anims=into_graph,
+ run_time=2
+ )
+
+ def get_area(self,graph=False):
+ axes=self.axes
+ if graph:
+ on_surface=self.on_surface_graph
+ on_base=self.line_graph
+ else:
+ on_surface=self.values_on_surface
+ on_base=self.line_of_int
+ area =Polygon(
+ *[
+ on_surface.get_point_from_function(t)
+ for t in np.arange(0,PI,0.01)
+ ],
+ *[
+ on_base.get_point_from_function(t)
+ for t in np.arange(PI,0,-0.01)
+ ],
+ stroke_width=0,
+ fill_color=TEAL_A,
+ fill_opacity=.6,
+ )
+
+ return area
+
+ def get_curve(self,func,on_surface=False ,**kwargs):
+ config = dict()
+ config.update(self.default_graph_style)
+ config.update({
+ "t_min": 0,
+ "t_max": PI,
+ })
+ config.update(kwargs)
+ r=abs(self.axes.a)
+ curve=ParametricFunction(
+ lambda t: self.axes.c2p(
+ r*np.cos(t),
+ r*np.sin(t),
+ func(r*np.cos(t), r*np.sin(t))*bool(on_surface)
+ ),
+ **config,
+ )
+ return curve
+
+
+ def get_surface(self, func, **kwargs):
+ axes=self.axes
+ config = {
+ "u_min": axes.a-.2,
+ "u_max": axes.b+.2,
+ "v_min": axes.c-.1,
+ "v_max": axes.d,
+ "resolution": (
+ 2*(axes.y_max - axes.y_min) // axes.y_axis.tick_frequency,
+ (axes.x_max - axes.x_min) // axes.x_axis.tick_frequency,
+ ),
+ }
+
+ config.update(self.default_surface_config)
+ config.update(kwargs)
+ return ParametricSurface(
+ lambda x,y : axes.c2p(
+ x, y, func(x, y)
+ ),
+ **config
+ )
+
+ def get_graph(self,func,on_surface=False ,**kwargs):
+ config = dict()
+ config.update(self.default_graph_style)
+ config.update({
+ "t_min": 0,
+ "t_max": PI,
+ })
+ config.update(kwargs)
+ slice_curve=ParametricFunction(
+ lambda t: self.axes.c2p(
+ 4*np.cos(t),
+ 0,
+ 2+func(3*np.cos(t), 3*np.sin(t))*bool(on_surface)
+ ),
+ **config,
+ )
+ return slice_curve
+
+ def get_lines(self):
+ pass
+ axes = self.axes
+ labels=[axes.x_axis.n2p(axes.a), axes.x_axis.n2p(axes.b), axes.y_axis.n2p(axes.c),
+ axes.y_axis.n2p(axes.d)]
+
+
+ surface_corners=[]
+ for x,y,z in self.region_corners:
+ surface_corners.append([x,y,self.Func(x,y)])
+
+ lines=VGroup()
+ for start , end in zip(surface_corners,
+ self.region_corners):
+ lines.add(self.draw_lines(start,end,"PINK"))
+
+ for start , end in zip(labels,
+ self.region_corners):
+ # lines.add(self.draw_lines(start,end,"BLUE"))
+ # print (start,end)
+ pass
+ # self.play(ShowCreation(lines))
+ self.add(lines)
+
+
+ def draw_lines(self,start,end,color):
+ start=self.axes.c2p(*start)
+ end=self.axes.c2p(*end)
+ line=DashedLine(start,end,color=color)
+
+ return line
+
+#-------------------------------------------------------
+ #customize 3D axes
+ def get_three_d_axes(self, include_labels=True, include_numbers=True, **kwargs):
+ config = dict(self.axes_config)
+ config.update(kwargs)
+ axes = ThreeDAxes(**config)
+ axes.set_stroke(width=2)
+ self.axes=axes
+
+ if include_numbers:
+ self.add_axes_numbers(axes)
+
+ if include_labels:
+ self.add_axes_labels(axes)
+
+ # Adjust axis orientation
+ axes.x_axis.rotate(
+ -90 * DEGREES, LEFT,
+ about_point=axes.c2p(0, 0, 0),
+ )
+ axes.y_axis.rotate(
+ 90 * DEGREES, UP,
+ about_point=axes.c2p(0, 0, 0),
+ )
+
+ # Add xy-plane
+ input_plane = self.get_surface(
+ lambda x, t: 0
+ )
+ '''input_plane.set_style(
+ fill_opacity=0.3,
+ fill_color=PINK,
+ stroke_width=.2,
+ stroke_color=WHITE,
+ )'''
+
+ axes.input_plane = input_plane
+
+ self.region_corners=[
+ input_plane.get_corner(pos) for pos in (DL,DR,UR,UL)]
+
+ return axes
+
+
+ def setup_axes(self):
+ axes = self.get_three_d_axes(include_labels=True)
+ axes.add(axes.input_plane)
+ axes.scale(1)
+ # axes.center()
+ axes.shift(axes.axes_shift)
+
+ self.add(axes)
+ self.axes = axes
+
+ def add_axes_numbers(self, axes):
+ x_axis = axes.x_axis
+ y_axis = axes.y_axis
+ tex_vals_x = [
+
+ ("1", axes.b),
+ ("-1", axes.a),
+ ]
+ tex_vals_y=[
+
+ ("1", axes.d)
+ ]
+ x_labels = VGroup()
+ y_labels = VGroup()
+ for tex, val in tex_vals_x:
+ label = TexMobject(tex)
+ label.scale(1)
+ label.next_to(x_axis.n2p(val), DOWN)
+ # label.rotate(180 * DEGREES)
+ x_labels.add(label)
+ x_axis.add(x_labels)
+ x_axis.numbers = x_labels
+
+ for tex, val in tex_vals_y:
+ label = TexMobject(tex)
+ label.scale(1)
+ label.next_to(y_axis.n2p(val), LEFT)
+ label.rotate(90 * DEGREES)
+ y_labels.add(label)
+
+ y_axis.add(y_labels)
+ y_axis.numbers = y_labels
+
+ return axes
+
+ def add_axes_labels(self, axes):
+ x_label = TexMobject("x")
+ x_label.next_to(axes.x_axis.get_end(), RIGHT)
+ axes.x_axis.label = x_label
+
+ y_label = TextMobject("y")
+ y_label.rotate(90 * DEGREES, OUT)
+ y_label.next_to(axes.y_axis.get_end(), UP)
+ axes.y_axis.label = y_label
+
+ z_label = TextMobject("z")
+ z_label.rotate(90 * DEGREES, RIGHT)
+ z_label.next_to(axes.z_axis.get_zenith(), LEFT)
+ axes.z_axis.label = z_label
+ for axis in axes:
+ axis.add(axis.label)
+ return axes
+
+
+
+ #uploaded by Somnath Pandit.FSF2020_Line_Integrals
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/file3_vector_line_int_as_sum.py b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/file3_vector_line_int_as_sum.py
new file mode 100644
index 0000000..78294cc
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/file3_vector_line_int_as_sum.py
@@ -0,0 +1,326 @@
+from manimlib.imports import *
+
+
+class LineIntegrationAsSum(GraphScene):
+ CONFIG = {
+ "x_min" : 0,
+ "x_max" : 10,
+ "y_min" : 0,
+ "y_max" : 6,
+ "graph_origin": ORIGIN+5*LEFT+3*DOWN,
+ "x_axis_width": 10,
+ "y_axis_height": 6 ,
+ "x_tick_frequency": 2,
+ "y_tick_frequency": 2,
+ "Func":lambda x : 1+x**1.3*np.exp(-.12*(x-2)**2)*np.sin(x/4),
+ "a": 1 ,"b": 9, "n": 15,
+ }
+
+ def construct(self):
+ X = RIGHT*self.x_axis_width/(self.x_max- self.x_min)
+ Y = UP*self.y_axis_height/(self.y_max- self.y_min)
+ self.X=X ;self.Y=Y
+
+ self.setup_axes(animate=False)
+
+
+ curve=self.get_graph(
+ self.Func,
+ x_min=self.a,
+ x_max=self.b,
+ )
+ curve.set_color([BLACK,BLUE,BLUE,BLUE,BLACK])
+ curve_label= self.get_graph_label(
+ curve,
+ label="\\text{path of intgration}",
+ x_val=4,
+ direction=UR,
+ buff=.6,
+ color=BLUE
+ )
+ self.curve=curve
+ self.curve_label=curve_label
+
+ self.get_vector_field()
+
+
+ self.play(ShowCreation(VGroup(curve,curve_label)))
+ self.wait(.6)
+ self.break_in_arcs()
+ self.show_the_sum()
+
+ self.wait(2)
+
+
+ def get_vector_field(self):
+ func = lambda v: np.array([
+ v[0], # x
+ -v[1], # y
+ 0 # z
+ ])
+ vector_field= VectorField(
+ func,
+ delta_x=1,
+ delta_y=1,
+ colors=[GREEN_A,GREEN_C],
+ length_func= lambda norm: .8*sigmoid(norm),
+ vector_config={
+ "stroke_width": 2
+ }
+ )
+
+ self.vector_field= vector_field
+
+
+ def break_in_arcs(self):
+
+ self.write_about_breaking()
+
+ dl=0.8
+ self.get_breakers(dl)
+ self.wait(2)
+ self.play(FadeOut(self.upto_break_text))
+ self.dl=dl
+
+ def write_about_breaking(self):
+ breaking_text=TextMobject("\\texttt{..broken}"," into small", "subarcs")
+ breaking_text.set_color_by_tex_to_color_map({
+ "broken":RED,"subarcs": BLUE
+ })
+ breaking_text.next_to(self.curve_label,DOWN)
+ breaking_text.align_to(self.curve_label,LEFT)
+ self.play(
+ Write(breaking_text)
+ )
+
+ self.upto_break_text=VGroup(
+ self.curve_label,
+ breaking_text,
+ )
+
+ def get_breakers(self,dl):
+ point=self.a
+ points=[]
+ while point<(self.b-dl) :
+ start=point
+ end=point+dl
+ points += [end]
+ breaker=Line(
+ self.input_to_graph_point(start,self.curve),
+ self.input_to_graph_point(end,self.curve),
+ stroke_width=2,
+ color=RED,
+ )
+ breaker.rotate(PI/2).scale(.5)
+
+ point=end
+ self.play(FadeIn(breaker),run_time=.2)
+ # self.add(breaker)
+
+ del points[-1]
+ self.points=points
+
+
+ def show_the_sum(self):
+ at_any_points_text=TextMobject("At any ","point", "in each ", "subarc")
+ at_any_points_text.set_color_by_tex_to_color_map({
+ "point":YELLOW , "subarc": BLUE
+ })
+ at_any_points_text.to_edge(TOP,buff=SMALL_BUFF)
+
+ evaluate_text=TextMobject("$\\vec F(x,y)$ ", "is evaluated").next_to(at_any_points_text,DOWN)
+ evaluate_text.set_color_by_tex("$\\vec F(x,y)$",ORANGE)
+
+ multiply_text=TextMobject("...is multiplied with ","$\\Delta s_i$")
+ multiply_text.set_color_by_tex("\\Delta s_i", BLUE)
+ multiply_text.next_to(at_any_points_text,DOWN)
+
+
+
+ self.at_any_points_text=at_any_points_text
+ self.evaluate_text=evaluate_text
+ self.multiply_text=multiply_text
+
+ dots=[]
+ for point in self.points:
+
+ dot=Dot(
+ point=self.input_to_graph_point(point,self.curve),
+ radius= .7*DEFAULT_DOT_RADIUS,
+ stroke_width= 0,
+ fill_opacity= 1.0,
+ color= YELLOW,
+ )
+ dots+=[dot]
+
+ self.play(
+ Write(at_any_points_text),
+ FadeIn(VGroup(*dots)),run_time=1.5
+ )
+ self.dots=dots
+
+ self.wait()
+ self.show_the_dot_product()
+ self.multiply_with_ds()
+ self.construct_equation()
+
+
+ def show_the_dot_product(self):
+ index=-(len(self.points)//3)
+ self.index=index
+
+ dot=self.dots[index]
+
+
+ dot_prod_text=TextMobject("Dot Product of", "$\\vec F(x_i,y_i)$", "and","$\\vec T(x_i,y_i)$")
+ dot_prod_text.set_color_by_tex_to_color_map({
+ "\\vec F(x_i,y_i)":ORANGE ,
+ "\\vec T(x_i,y_i)": "#DC75CD" ,
+ })
+ dot_prod_text.to_edge(TOP,buff=SMALL_BUFF)
+
+
+ point_coord=TextMobject("$(x_i,y_i)$",color=YELLOW)
+ point_coord.next_to(dot,DL,buff=.01).scale(.8)
+
+ func_val=TextMobject("$\\vec F(x_i,y_i)$",color=ORANGE)
+ func_val.next_to(dot,UR).scale(.8)
+
+ self.dot_prod_text=dot_prod_text
+ self.func_val=func_val
+
+ dot.set_color(ORANGE).scale(1.2)
+
+
+ self.play(FadeIn(VGroup(point_coord,dot)))
+ self.play(Write(self.evaluate_text))
+ self.wait(1)
+ self.play(FadeOut(self.vector_field))
+ self.get_vector_and_tangent()
+ self.dot_product()
+
+
+ self.wait(2)
+ self.remove(point_coord)
+
+
+ def get_vector_and_tangent(self):
+ dot=self.dots[self.index]
+ self.show_specific_vectors(dot)
+ self.play(Write(self.func_val))
+ self.wait(1)
+ self.show_tangent(dot)
+ self.play(FadeIn(VGroup(*[
+ dot.set_color(ORANGE).scale(1.4)
+ for dot in self.dots ]
+ )))
+
+
+ def show_specific_vectors(self,dots):
+ for dot in dots:
+ vector=self.vector_field.get_vector(dot.get_center())
+ vector.set_color(ORANGE)
+
+ self.play(Write(vector),run_time=.2)
+
+
+ def show_tangent(self,dot):
+ tangent_sym=TextMobject("$\\vec T(x_i,y_i)$",color="#DC75CD").scale(.8)
+ x=dot.get_center()
+ angle=self.angle_of_tangent(
+ self.point_to_coords(x)[0],
+ self.curve,
+ dx=0.01
+ )
+ vect = Vector().rotate(angle,about_point=x)
+ vect.set_color("#DC75CD")
+ tangent=vect.next_to(x,DR,buff=0)
+ tangent_sym.next_to(tangent,DOWN,buff=.1)
+ self.play(Write(VGroup(tangent,tangent_sym)))
+
+ self.tangent_sym=tangent_sym
+
+ def dot_product(self):
+
+ dot_sym=Dot().next_to(self.func_val,RIGHT)
+
+ self.play(FadeOut(VGroup(
+ self.at_any_points_text,
+ self.evaluate_text
+ )))
+ self.play(Write(self.dot_prod_text))
+ self.play(
+ FadeIn(dot_sym),
+ ApplyMethod(
+ self.tangent_sym.next_to,
+ dot_sym, RIGHT
+ ))
+
+ self.dot_sym=dot_sym
+
+ def multiply_with_ds(self):
+ self.get_ds()
+
+ self.play(GrowFromCenter(self.ds_brace_group))
+ self.wait(2)
+ self.play(Write(self.multiply_text))
+ self.play(ApplyMethod(
+ self.ds_brace_label.next_to,
+ self.tangent_sym, RIGHT,buff=.15
+ ))
+
+
+
+ def get_ds(self):
+ p1= self.dots[self.index]
+ p2= self.dots[self.index+1]
+ ds_brace=Brace(VGroup(p1,p2),DL)
+ ds_brace.move_to(p1,UR)
+ ds_brace_label=ds_brace.get_text("$\Delta s_i$", buff = .05)
+ ds_brace_label.set_color(BLUE)
+ self.ds_brace=ds_brace
+ self.ds_brace_label=ds_brace_label
+ self.ds_brace_group=VGroup(ds_brace,ds_brace_label)
+
+
+ def construct_equation(self):
+ sum_up_text=TextMobject("and"," summed ", "for all i' s")
+ sum_up_text.set_color_by_tex("summed",PURPLE_A)
+ sum_up_text.next_to(self.multiply_text,DOWN,buff=MED_SMALL_BUFF)
+ sum_up_text.shift(LEFT)
+
+ sum_eqn=TextMobject("$$\\sum_i^{ } $$").set_color(PURPLE_A)
+ sum_eqn.move_to(self.graph_origin+6.5*self.X+4*self.Y)
+
+ line_integral_text=TextMobject("The Value of the"," line ","integral is").to_edge(TOP,buff=MED_SMALL_BUFF)
+ line_integral_text.set_color_by_tex("line",BLUE_C)
+ approx=TextMobject("$\\approx$",color=RED).next_to(sum_eqn,LEFT)
+ multipled=VGroup(
+ self.func_val,
+ self.dot_sym,
+ self.tangent_sym,
+ self.ds_brace_label
+ )
+
+
+ self.play(Write(sum_up_text))
+ self.show_specific_vectors(self.dots)
+ self.play(FadeIn(sum_eqn))
+ self.play(ApplyMethod(
+ multipled.next_to,sum_eqn,RIGHT
+ ))
+ self.wait()
+ self.play(FadeOut(VGroup(
+ self.dot_prod_text,
+ self.multiply_text,
+ sum_up_text
+ )))
+ self.play(Write(line_integral_text))
+ self.play(FadeIn(approx))
+
+
+
+#uploaded by Somnath Pandit.FSF2020_Line Integrals
+
+
+
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/file4_vector_line_integral.py b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/file4_vector_line_integral.py
new file mode 100644
index 0000000..6730820
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/file4_vector_line_integral.py
@@ -0,0 +1,374 @@
+from manimlib.imports import *
+
+class LineIntegrationProcess(GraphScene):
+
+ CONFIG = {
+ "x_min" : -0,
+ "x_max" : 1,
+ "y_min" : -0,
+ "y_max" : 1,
+ "axes_color":WHITE,
+ "graph_origin": ORIGIN+6.3*LEFT+3*DOWN,
+ "x_axis_width": 5.5,
+ "y_axis_height": 5.5,
+ "x_tick_frequency": 1,
+ "y_tick_frequency": 1,
+ "default_vector_field_config": {
+ "delta_x": .5,
+ "delta_y": .5,
+ "min_magnitude": 0,
+ "max_magnitude": 15,
+ "colors": [BLUE],
+ "length_func": lambda norm : norm/35,
+ "opacity": 1.0,
+ "vector_config": {
+ "stroke_width":2
+ },
+ },
+ "default_graph_style": {
+ "stroke_width": 2,
+ "stroke_color": WHITE,
+ },
+ }
+
+
+ def construct(self):
+ X = RIGHT*self.x_axis_width/(self.x_max- self.x_min)
+ Y = UP*self.y_axis_height/(self.y_max- self.y_min)
+ self.X=X ;self.Y=Y
+
+ self.setup_axes(animate=False)
+
+ fn_text=TexMobject(
+ r"\vec F = x^2\hat i-xy\hat j",
+ stroke_width=2.5
+ ).set_color_by_gradient(
+ *self.default_vector_field_config["colors"]
+ )
+ fn_text.to_edge(TOP,buff=.1).shift(2*LEFT)
+
+ origin=self.graph_origin
+ v_field=self.get_vector_field(
+ lambda v: np.array([
+ (v[0]-origin[0])**2,
+ -(v[0]-origin[0])*(v[1]-origin[1]),
+ 0,
+ ]),
+ x_min= -.001+origin[0],
+ x_max= 5.4+origin[0],
+ y_min= -0+origin[1],
+ y_max= 5.5+origin[1],
+ )
+
+ self.add(v_field, fn_text)
+ self.play(Write(fn_text))
+ self.wait(2)
+ self.get_line_of_int()
+ self.get_dot_product_values()
+ self.wait(2)
+ self.remove(v_field,fn_text)
+ self.write_area_as_intgral_value()
+ self.wait(2)
+
+
+ def get_vector_field(self,func,**kwargs):
+ config = dict()
+ config.update(self.default_vector_field_config)
+ config.update(kwargs)
+ vector_field= VectorField(func,**config)
+ self.vector_field=vector_field
+
+ return vector_field
+
+ def get_line_of_int(self):
+ line_of_int_text=TextMobject(
+ r"Line of integration is\\",
+ "$\\vec r(t)=\cos(t)\hat i+\sin(t)\hat j$"
+ )
+ line_of_int_text[1].set_color(PINK)
+ line_of_int_text.to_corner(UR,buff=.8)
+
+
+ line_of_int= self.get_graph(
+ lambda x : np.sqrt(1-x**2),
+ x_min=1,
+ x_max=0,
+ )
+ line_of_int.set_style(
+ stroke_width=3,
+ stroke_color=PINK,
+ )
+
+ self.play(Write(line_of_int_text))
+ self.wait(.5)
+ self.play(ShowCreation(line_of_int),run_time=2)
+ # self.add(line_of_int)
+
+ self.line_of_int=line_of_int
+ self.line_of_int_text=line_of_int_text
+
+
+ def get_dot_product_values(self):
+ t_tracker = ValueTracker(0)
+ self.t_tracker = t_tracker
+ self.get_vector_and_tangent()
+ self.get_dot_product_graph()
+ self.wait(1.5)
+ self.play(ApplyMethod(
+ self.t_tracker.set_value, PI/6,
+ rate_func=linear,
+ run_time=2.5,
+ )
+ )
+ self.wait(1)
+ self.play(ApplyMethod(
+ self.t_tracker.set_value, PI/2,
+ rate_func=linear,
+ run_time=4,
+ )
+ )
+ self.dot_prod_graph.suspend_updating()
+
+ def get_vector_and_tangent(self):
+ vect_tangent_text=TextMobject(
+ "Get the"," vector",r" and\\"," tangent",
+ " on the"," line"
+ )
+ vect_tangent_text.set_color_by_tex_to_color_map({
+ "tangent": ORANGE, "vector": YELLOW, "line":PINK
+ })
+ vect_tangent_text.to_corner(UR,buff=.8)
+ self.vect_tangent_text= vect_tangent_text
+
+ self.play(FadeOut(self.axes))
+ self.remove(self.line_of_int_text)
+ self.play(Write(vect_tangent_text))
+ self.show_vector()
+ self.show_tangent()
+ self.wait(1.3)
+
+ def show_vector(self):
+ t = self.t_tracker.get_value
+ vect_label=TextMobject(
+ "$\\vec F(x_i,y_i)$",
+ color=YELLOW,
+ stroke_width=2
+ ).scale(.8)
+
+ vector = always_redraw( lambda:
+ self.vector_field.get_vector(
+ self.coords_to_point(
+ np.cos(t()), np.sin(t())
+ ),
+ stroke_width=6,
+ max_stroke_width_to_length_ratio= 8,
+ ).set_color(YELLOW),
+ )
+
+ vect_label.next_to(vector,RIGHT,buff=.1)
+ vector_group= VGroup(vector,vect_label)
+
+ # self.add(vector_group)
+ self.play(Write(vector_group),run_time=1)
+ self.wait(.4)
+
+ self.vect_label = vect_label
+ self.vector_group= vector_group
+
+ def show_tangent(self):
+ tangent_label=TextMobject(
+ "$\\vec T(x_i,y_i)$",
+ color=ORANGE,
+ stroke_width=2
+ ).scale(.8)
+
+ t = self.t_tracker.get_value
+
+ tangent = always_redraw(lambda:
+ Vector(
+ color=ORANGE,
+ stroke_width=6,
+ ).scale(1).next_to(
+ self.coords_to_point(
+ np.cos(t()), np.sin(t())
+ ),DR,buff=-.1
+ ).rotate(
+ self.angle_of_tangent(
+ np.cos(t()),
+ self.line_of_int,
+ dx=-0.00001
+ ),
+ about_point=self.coords_to_point(
+ np.cos(t()), np.sin(t())
+ )
+ )
+ )
+ tangent_label.next_to(tangent,UP,buff=.1)
+ tangent_group=VGroup(tangent,tangent_label)
+
+ # self.add(tangent_group)
+ self.play(Write(tangent_group))
+ self.wait(.6)
+
+ self.tangent_label=tangent_label
+ self.tangent_group=tangent_group
+
+ def get_dot_product_graph(self):
+ t = self.t_tracker.get_value
+
+ self.start_x= 1.3 ; self.end_x=2.3
+
+ t_axis= self.get_graph(
+ lambda x : 2.0/5,
+ x_min= self.start_x,
+ x_max= self.end_x,
+ ).set_style(
+ stroke_width=4,
+ )
+
+ dot_prod_axis= Vector(3*UP).next_to(
+ t_axis,LEFT,buff=-.1
+ ).set_color(GREEN)
+ dot_prod_label=TexMobject(
+ "\\vec F","\\cdot","\\vec T",
+ stroke_width= 1.5,
+ ).next_to(dot_prod_axis,UP).scale(.8)
+ dot_prod_label[0].set_color(YELLOW)
+ dot_prod_label[2].set_color(ORANGE)
+
+ dot_prod_graph_axes= VGroup(t_axis,dot_prod_axis)
+
+ self.write_about_graph()
+ self.wait(1)
+ # self.add(dot_prod_graph_axes)
+ self.play(Write(dot_prod_graph_axes))
+ self.show_the_parameter(t,t_axis)
+ self.wait(.6)
+ self.play(ReplacementTransform(
+ self.vect_label,dot_prod_label[0]
+ ))
+ self.play(ReplacementTransform(
+ self.tangent_label,dot_prod_label[1:3]
+ ))
+ self.show_graph_area(t_axis)
+
+ self.dot_prod_graph_axes= dot_prod_graph_axes
+ self.dot_prod_label= dot_prod_label
+
+ def write_about_graph(self):
+ graph_text=TextMobject(
+ "Graph",r" of the "," vector",r" $-$\\ ",
+ r"tangent",r" dot product\\",
+ " with the parameter ","$t$"
+ )
+ graph_text.set_color_by_tex_to_color_map({
+ "Graph":GREEN, "vector": YELLOW,
+ "tangent":ORANGE, "$t$":RED
+ })
+ graph_text.to_corner(UR,buff=.5)
+ self.graph_text=graph_text
+
+ self.remove(self.vect_tangent_text)
+ self.play(Write(graph_text),run_time=4)
+
+ def show_the_parameter(self,t,t_axis):
+ t_dot=Dot(color=RED).next_to(t_axis,LEFT,buff=0)
+ t_dot.add_updater(lambda obj :
+ obj.move_to(self.c2g([t(),0])
+ ))
+ t_text=TextMobject("$t$=").next_to(t_dot,UP,buff=.25)
+ t_val=always_redraw(
+ lambda: DecimalNumber(
+ t()/PI,
+ color=GOLD
+ ).next_to(t_text,RIGHT,buff=0).scale(.8)
+ )
+ t_label=VGroup(
+ t_text,t_val
+ ).set_color(RED)
+
+
+ pi = TexMobject(
+ "\\pi ",
+ color=GOLD,
+ ).next_to(t_val,RIGHT,buff=0.05)
+ t_label.add(pi)
+
+ t_label.add_updater(lambda label :
+ label.next_to(t_dot,UP)
+ )
+
+ t_group=VGroup(t_dot,t_label)
+
+ # self.add(t_group)
+ self.play(Write(t_group))
+
+ self.t_group= t_group
+
+
+ def show_graph_area(self,t_axis):
+ t = self.t_tracker.get_value
+ dot_prod_graph= always_redraw(lambda: Polygon(
+ *[
+ self.c2g([t,-2*np.cos(t)**2*np.sin(t)])
+ for t in np.arange(0,t(),0.01)
+ ],
+ *[
+ self.c2g([t,0])
+ for t in [ t(),0 ]
+ ],
+ stroke_width=2.5,
+ fill_color=TEAL_D,
+ fill_opacity=.6,
+ ))
+
+ self.add(dot_prod_graph)
+
+ self.dot_prod_graph=dot_prod_graph
+
+ def c2g(self,coord):
+ """ get points for the dot product graph
+ from its coordinates"""
+
+ return self.coords_to_point(
+ self.start_x+coord[0]/(PI/2),
+ 2.0/5+coord[1]/2,
+ )
+
+
+ def write_area_as_intgral_value(self):
+ area_text=TextMobject(
+ "Value of the "," line"," integral in the",
+ r"Vector field\\",
+ "is equal to this ","area"
+ )
+ area_text.set_color_by_tex_to_color_map({
+ "Vector field": BLUE, "line":PINK, "area":TEAL_C
+ })
+ area_text.to_edge(TOP,buff=MED_SMALL_BUFF)
+
+
+ self.play(FadeOut(VGroup(
+ self.line_of_int,
+ self.vector_group,
+ self.tangent_group,
+ self.t_group,
+ self.dot_prod_graph_axes,
+ self.dot_prod_label,
+ self.graph_text
+ )
+ ))
+ area= self.dot_prod_graph.copy().scale(1.3)
+ area.next_to(area_text,DOWN,buff=1.5)
+
+ # self.add(area_text)
+ self.play(Write(area_text),run_time=4)
+ self.play(ReplacementTransform(
+ self.dot_prod_graph,
+ area
+ ))
+ self.wait(.5)
+
+ #uploaded by Somnath Pandit.FSF2020_Line_Integrals
+
+
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/file5_helix.py b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/file5_helix.py
new file mode 100644
index 0000000..50aeb33
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/file5_helix.py
@@ -0,0 +1,245 @@
+from manimlib.imports import *
+
+class ParametricCurve(ThreeDScene):
+
+ CONFIG = {
+ "axes_config": {
+ "x_min": 0,
+ "x_max": 3,
+ "y_min": 0,
+ "y_max": 3,
+ "z_min": 0,
+ "z_max": 4,
+ "a":0 ,"b": 2, "c":0 , "d":2,
+ "axes_shift":2*IN+1.4*RIGHT+1.4*DOWN,
+ "x_axis_config": {
+ "tick_frequency": 1,
+ "include_tip": False,
+ },
+ "y_axis_config": {
+ "tick_frequency": 1,
+ "include_tip": False,
+ },
+ "z_axis_config": {
+ "tick_frequency": 1,
+ # "include_tip": False,
+ },
+ },
+
+ }
+
+
+ def construct(self):
+
+ self.setup_axes()
+
+ self.set_camera_orientation(
+ distance=25,
+ phi=60 * DEGREES,
+ theta=40 * DEGREES,
+ )
+
+ label=TextMobject("Helix",color=PURPLE).scale(1.6)
+ label.to_corner(UR,buff=2)
+ self.add_fixed_in_frame_mobjects(label)
+
+ helix=self.get_helix(
+ radius=1.5,
+ t_min= 0,
+ t_max= 4*PI,
+ color=PURPLE
+ )
+ parameter_label=TextMobject(
+ "Parametric equation: ",
+ color=TEAL
+ ).next_to(label,DOWN,buff=.3
+ )
+ parametric_eqn=TextMobject(
+ "$x=\cos$ (","t",
+ r")\\$y=\sin $(","t",
+ r")\\$z$=","t"
+ ).next_to(parameter_label,DOWN,buff=.1)
+ parametric_eqn.set_color_by_tex("t",RED)
+ self.parametric_eqn=parametric_eqn
+
+ parametriztion=VGroup(
+ parameter_label,
+ parametric_eqn
+ )
+
+
+ self.play(ShowCreation(helix),run_time=2)
+ self.begin_ambient_camera_rotation(.1)
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(parametriztion)
+ self.play(Write(parametriztion))
+ self.wait(1)
+ self.stop_ambient_camera_rotation()
+ self.move_camera(
+ distance=20,
+ phi=85 * DEGREES,
+ # theta=-90 * DEGREES,
+ run_time=3
+ )
+ scale_axes=VGroup(self.axes,helix).scale(1.2)
+ self.show_the_parameter()
+ self.wait(2)
+
+
+
+ def get_helix(self,radius=1, **kwargs):
+ config = {
+ "t_min": 0,
+ "t_max": 2*PI,
+ }
+ config.update(kwargs)
+ helix= ParametricFunction(
+ lambda t : self.axes.c2p(
+ radius*np.cos(t),
+ radius*np.sin(t),
+ t/4
+ ),
+ **config
+ )
+
+ self.helix=helix
+ return helix
+
+ def show_the_parameter(self):
+ t_tracker = ValueTracker(0)
+ t=t_tracker.get_value
+
+ t_label = TexMobject(
+ "t = ",color=RED
+ ).next_to(self.parametric_eqn,DL,buff=.85)
+
+ t_text = always_redraw(
+ lambda: DecimalNumber(
+ t(),
+ color=GOLD,
+ ).next_to(t_label, RIGHT, MED_SMALL_BUFF)
+ )
+ t_text.suspend_updating()
+
+ dot = Sphere(
+ radius= 1.5*DEFAULT_DOT_RADIUS,
+ stroke_width= 1,
+ fill_opacity= 1.0,
+ )
+ dot.set_color(GOLD)
+ dot.add_updater(lambda v: v.move_to(
+ self.helix.get_point_from_function(PI*t())
+ ))
+
+ pi = TexMobject(
+ "\\pi ",
+ color=GOLD,
+ ).next_to(t_text,RIGHT,buff=-.3)
+
+ group = VGroup(t_text,t_label,pi).scale(1.5)
+
+ self.wait(1)
+ self.add_fixed_in_frame_mobjects(group)
+ t_text.resume_updating()
+ self.play(FadeIn(group))
+ self.add(dot)
+ self.play(
+ t_tracker.set_value,2,
+ rate_func=linear,
+ run_time=5
+ )
+
+
+#--------------------------------------------------------
+
+ #customize 3D axes
+ def get_three_d_axes(self, include_labels=True, include_numbers=False, **kwargs):
+ config = dict(self.axes_config)
+ config.update(kwargs)
+ axes = ThreeDAxes(**config)
+ axes.set_stroke(width=1.5)
+
+ if include_numbers:
+ self.add_axes_numbers(axes)
+
+ if include_labels:
+ self.add_axes_labels(axes)
+
+ # Adjust axis orientation
+ axes.x_axis.rotate(
+ 90 * DEGREES, LEFT,
+ about_point=axes.c2p(0, 0, 0),
+ )
+ axes.y_axis.rotate(
+ 90 * DEGREES, UP,
+ about_point=axes.c2p(0, 0, 0),
+ )
+
+
+ return axes
+
+
+ def setup_axes(self):
+ axes = self.get_three_d_axes(include_labels=True)
+ axes.scale(1)
+ # axes.center()
+ axes.shift(axes.axes_shift)
+ self.add(axes)
+ self.axes = axes
+
+ def add_axes_numbers(self, axes):
+ x_axis = axes.x_axis
+ y_axis = axes.y_axis
+ tex_vals_x = [
+ ("1", axes.b),
+ ]
+ tex_vals_y=[
+ ("1", axes.d)
+ ]
+ x_labels = VGroup()
+ y_labels = VGroup()
+ for tex, val in tex_vals_x:
+ label = TexMobject(tex)
+ label.scale(1)
+ label.next_to(x_axis.n2p(val), DOWN)
+ label.rotate(180 * DEGREES)
+ x_labels.add(label)
+ x_axis.add(x_labels)
+ x_axis.numbers = x_labels
+
+ for tex, val in tex_vals_y:
+ label = TexMobject(tex)
+ label.scale(1)
+ label.next_to(y_axis.n2p(val), LEFT)
+ label.rotate(90 * DEGREES)
+ y_labels.add(label)
+
+ y_axis.add(y_labels)
+ y_axis.numbers = y_labels
+
+ return axes
+
+ def add_axes_labels(self, axes):
+ x_label = TexMobject("x")
+ x_label.next_to(axes.x_axis.get_end(), RIGHT)
+ axes.x_axis.label = x_label
+
+ y_label = TextMobject("y")
+ y_label.rotate(90 * DEGREES, OUT)
+ y_label.next_to(axes.y_axis.get_end(), UP)
+ axes.y_axis.label = y_label
+
+ z_label = TextMobject("z")
+ z_label.rotate(90 * DEGREES, LEFT)
+ z_label.next_to(axes.z_axis.get_zenith(), LEFT)
+ axes.z_axis.label = z_label
+ for axis in axes:
+ axis.add(axis.label)
+ return axes
+
+ #uploaded by Somnath Pandit.FSF2020_Line_integrals
+
+
+
+
+
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/gifs/file1_scalar_line_int_as_sum.gif b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/gifs/file1_scalar_line_int_as_sum.gif
new file mode 100644
index 0000000..17ea3f0
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/gifs/file1_scalar_line_int_as_sum.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/gifs/file2_scalar_line_integral.gif b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/gifs/file2_scalar_line_integral.gif
new file mode 100644
index 0000000..f9a8f98
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/gifs/file2_scalar_line_integral.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/gifs/file3_vector_line_int_as_sum.gif b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/gifs/file3_vector_line_int_as_sum.gif
new file mode 100644
index 0000000..46b35bc
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/gifs/file3_vector_line_int_as_sum.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/gifs/file4_vector_line_integral.gif b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/gifs/file4_vector_line_integral.gif
new file mode 100644
index 0000000..1be7e1e
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/gifs/file4_vector_line_integral.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/gifs/file5_helix.gif b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/gifs/file5_helix.gif
new file mode 100644
index 0000000..ceedb1f
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/line-integrals/gifs/file5_helix.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/vector-fields/README.md b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/vector-fields/README.md
new file mode 100644
index 0000000..d8c0956
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/vector-fields/README.md
@@ -0,0 +1,11 @@
+**file1_vector_fields**
+![file1_vector_fields](gifs/file1_vector_fields.gif)
+
+**file2_grad_of_scalar_function**
+![file2_grad_of_scalar_function](gifs/file2_grad_of_scalar_function.gif)
+
+**file3_constructing_vector_field**
+![file3_constructing_vector_field](gifs/file3_constructing_vector_field.gif)
+
+**file4_slope_field**
+![file4_slope_field](gifs/file4_slope_field.gif)
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/vector-fields/file1_vector_fields.py b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/vector-fields/file1_vector_fields.py
new file mode 100644
index 0000000..6b1b686
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/vector-fields/file1_vector_fields.py
@@ -0,0 +1,350 @@
+from manimlib.imports import *
+
+class VectorFields(ThreeDScene):
+
+ CONFIG = {
+ "axes_config": {
+ "x_min": -4,
+ "x_max": 4,
+ "y_min": -4,
+ "y_max": 4,
+ "z_min": -3,
+ "z_max": 3,
+ "a":-4 ,"b": 4, "c":-4 , "d":4,
+ "axes_shift": ORIGIN+2*LEFT,
+ "x_axis_config": {
+ "tick_frequency": 1,
+ # "include_tip": False,
+ },
+ "y_axis_config": {
+ "tick_frequency": 1,
+ # "include_tip": False,
+ },
+ "z_axis_config": {
+ "tick_frequency": 1,
+ # "include_tip": False,
+ },
+ "num_axis_pieces": 10,
+ },
+ "default_graph_style": {
+ "stroke_width": 2,
+ "stroke_color": WHITE,
+ },
+ "default_vector_field_config": {
+ "delta_x": .5,
+ "delta_y": .5,
+ "x_min": -3,
+ "x_max": 3,
+ "y_min": -3,
+ "y_max": 3,
+ "min_magnitude": 0,
+ "max_magnitude": 4,
+ "colors": [BLUE,GREEN,ORANGE,RED],
+ "length_func": lambda norm : .45*sigmoid(norm),
+ "opacity": 1.0,
+ "vector_config": {
+ "stroke_width":3.5,
+ "max_tip_length_to_length_ratio": 0.35,
+ "max_stroke_width_to_length_ratio": 8,
+ },
+ },
+
+ }
+
+
+ def construct(self):
+
+ self.setup_axes()
+ axes=self.axes
+
+ self.set_camera_orientation(distance=35,
+ phi=0 * DEGREES,
+ theta=-90 * DEGREES,
+ )
+ self.move_camera(frame_center=axes.c2p(0,0,0))
+
+ self.show_2d_field()
+ self.wait(3)
+
+ self.show_3d_field()
+ self.begin_ambient_camera_rotation(rate=-.3,)
+ self.wait(1.5)
+ axes.x_axis.rotate(
+ -90 * DEGREES, LEFT,
+ about_point=axes.c2p(0, 0, 0),
+ ),
+ axes.y_axis.rotate(
+ 90 * DEGREES, UP,
+ about_point=axes.c2p(0, 0, 0),
+ ),
+ self.move_camera(
+ # distance=20,
+ phi=85 * DEGREES,
+ rate_func=linear,
+ run_time=8
+ )
+ self.wait(5)
+
+
+ def show_2d_field(self):
+ d2_field_text=TexMobject(
+ r"\vec F(x,y)=-y\hat i+x\hat j",
+ stroke_width=1.5
+ ).set_color_by_gradient(
+ *self.default_vector_field_config["colors"]
+ )
+ d2_field_text.to_corner(UR,buff=.5)
+
+ d2_field = self.get_vector_field(
+ lambda v: np.array([
+ -v[1],
+ v[0],
+ 0
+ ]),
+ )
+ self.add_fixed_in_frame_mobjects(d2_field_text)
+ # self.add(d2_field)
+ self.play(Write(d2_field_text))
+ self.play(FadeIn(d2_field))
+
+ self.d2_field=d2_field
+ self.d2_field_text=d2_field_text
+
+ def show_3d_field(self):
+ d3_field_text=TexMobject(
+ r"\vec F(x,y,z)=-y\hat i+x\hat j+0 \hat k",
+ stroke_width=1.5
+ ).set_color_by_gradient(
+ *self.default_vector_field_config["colors"]
+ )
+ d3_field_text.to_corner(UR,buff=.5)
+
+ d3_field= self.get_vector_field(
+ lambda v: np.array([
+ -v[1],
+ v[0],
+ 0
+ # v[0]*v[2]
+ ]),
+ z_min=-2,
+ z_max= 2,
+ delta_x= 1,
+ delta_y= 1,
+ delta_z= 1,
+ length_func=lambda norm : .5*sigmoid(norm),
+ opacity= 1,
+ ThreeD=True
+ )
+
+ self.remove(self.d2_field,self.d2_field_text)
+ self.add_fixed_in_frame_mobjects(d3_field_text)
+ # self.add(d3_field)
+ self.play(Write(d3_field_text))
+ self.play(FadeIn(d3_field))
+
+ def get_vector_field(self,func,ThreeD=False,**kwargs):
+ config = dict()
+ config.update(self.default_vector_field_config)
+ config.update(kwargs)
+ if ThreeD:
+ vector_field= VectorField3D(func,**config)
+ else:
+ vector_field= VectorField(func,**config)
+
+ vector_field.move_to(self.axes.c2p(0,0,0))
+ self.vector_field=vector_field
+
+ return vector_field
+
+
+
+#-------------------------------------------------------
+ #customize 3D axes
+ def get_three_d_axes(self, include_labels=True, include_numbers=False, **kwargs):
+ config = dict(self.axes_config)
+ config.update(kwargs)
+ axes = ThreeDAxes(**config)
+ axes.set_stroke(width=2)
+ self.axes=axes
+
+ if include_numbers:
+ self.add_axes_numbers(axes)
+
+ if include_labels:
+ self.add_axes_labels(axes)
+
+ # Adjust axis orientation
+ axes.x_axis.rotate(
+ -0 * DEGREES, LEFT,
+ about_point=axes.c2p(0, 0, 0),
+ )
+ axes.y_axis.rotate(
+ 0 * DEGREES, UP,
+ about_point=axes.c2p(0, 0, 0),
+ )
+
+ return axes
+
+
+ def setup_axes(self):
+ axes = self.get_three_d_axes(include_labels=True)
+ axes.scale(1)
+ # axes.center()
+ axes.shift(axes.axes_shift)
+
+ self.add(axes)
+ self.axes = axes
+
+ def add_axes_numbers(self, axes):
+ x_axis = axes.x_axis
+ y_axis = axes.y_axis
+ tex_vals_x = [
+
+ ("1", axes.b),
+ ]
+ tex_vals_y=[
+
+ ("1", axes.d)
+ ]
+ x_labels = VGroup()
+ y_labels = VGroup()
+ for tex, val in tex_vals_x:
+ label = TexMobject(tex)
+ label.scale(1)
+ label.next_to(x_axis.n2p(val), DOWN)
+ # label.rotate(180 * DEGREES)
+ x_labels.add(label)
+ x_axis.add(x_labels)
+ x_axis.numbers = x_labels
+
+ for tex, val in tex_vals_y:
+ label = TexMobject(tex)
+ label.scale(1)
+ label.next_to(y_axis.n2p(val), LEFT)
+ label.rotate(90 * DEGREES)
+ y_labels.add(label)
+
+ y_axis.add(y_labels)
+ y_axis.numbers = y_labels
+
+ return axes
+
+ def add_axes_labels(self, axes):
+ x_label = TexMobject("x")
+ x_label.next_to(axes.x_axis.get_end(), RIGHT)
+ axes.x_axis.label = x_label
+
+ y_label = TextMobject("y")
+ y_label.rotate(90 * DEGREES, OUT)
+ y_label.next_to(axes.y_axis.get_end(), UP)
+ axes.y_axis.label = y_label
+
+ z_label = TextMobject("z")
+ z_label.rotate(90 * DEGREES, RIGHT)
+ z_label.next_to(axes.z_axis.get_zenith(), LEFT)
+ axes.z_axis.label = z_label
+ for axis in axes:
+ axis.add(axis.label)
+ return axes
+
+#-----------------------------------------------------------
+
+class VectorField3D(VGroup):
+ CONFIG = {
+ "delta_x": 1,
+ "delta_y": 1,
+ "delta_z": 1,
+ "x_min": int(np.floor(-FRAME_WIDTH / 2)),
+ "x_max": int(np.ceil(FRAME_WIDTH / 2)),
+ "y_min": int(np.floor(-FRAME_HEIGHT / 2)),
+ "y_max": int(np.ceil(FRAME_HEIGHT / 2)),
+ "z_min":-1,
+ "z_max": 1,
+ "min_magnitude": 0,
+ "max_magnitude": 4,
+ "colors": DEFAULT_SCALAR_FIELD_COLORS,
+ # Takes in actual norm, spits out displayed norm
+ "length_func": lambda norm: 0.45 * sigmoid(norm),
+ "opacity": 1.0,
+ "vector_config": {},
+ }
+ '''Position of the tip of vector to be fixed'''
+ def __init__(self, func, **kwargs):
+ VGroup.__init__(self, **kwargs)
+ self.func = func
+ self.rgb_gradient_function = get_rgb_gradient_function(
+ self.min_magnitude,
+ self.max_magnitude,
+ self.colors,
+ flip_alphas=False
+ )
+ x_range = np.arange(
+ self.x_min,
+ self.x_max + self.delta_x,
+ self.delta_x
+ )
+ y_range = np.arange(
+ self.y_min,
+ self.y_max + self.delta_y,
+ self.delta_y
+ )
+ z_range = np.arange(
+ self.z_min,
+ self.z_max + self.delta_z,
+ self.delta_z
+ )
+ for x, y, z in it.product(x_range, y_range, z_range):
+ point = x * RIGHT + y * UP + z * OUT
+ # print(point)
+ self.add(self.get_vector(point))
+ self.set_opacity(self.opacity)
+
+ def get_vector(self, point, **kwargs):
+ output = np.array(self.func(point))
+ norm = get_norm(output)
+ if norm == 0:
+ output *= 0
+ else:
+ output *= self.length_func(norm) / norm
+ # norm=np.linalg.norm(output)
+ vector_config = dict(self.vector_config)
+ vector_config.update(kwargs)
+
+ vect = Vector(
+ output,
+ **vector_config
+ )
+ vect_perp=vect.copy().rotate(PI/2, axis=output)
+ vect= VGroup(vect,vect_perp)
+ # vect= self.position_vector(vect,point,output,norm)
+ vect.shift(point)
+ fill_color = rgb_to_color(
+ self.rgb_gradient_function(np.array([norm]))[0]
+ )
+ vect.set_color(fill_color)
+ return vect
+
+ '''def position_vector(self,vect,point,output,norm):
+ theta,phi=self.get_theta_phi(output,norm)
+ vect.rotate(PI-phi, axis=RIGHT)
+ vect.rotate(theta, axis=IN)
+ # or apply rotation matrix?
+ return vect
+
+ def get_theta_phi(self,output,norm):
+ if norm==0:
+ phi,theta=0,0
+ else:
+ phi= np.arccos(output[-1]/norm)
+ if output[0]!=0:
+ theta= np.arccos(output[0]/(norm*np.sin(phi)))
+ else:
+ theta= 0
+ return phi,theta'''
+
+
+
+ #uploaded by Somnath Pandit. FSF2020_Vector_fields
+
+
+
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/vector-fields/file2_grad_of_scalar_function.py b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/vector-fields/file2_grad_of_scalar_function.py
new file mode 100644
index 0000000..231b15c
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/vector-fields/file2_grad_of_scalar_function.py
@@ -0,0 +1,320 @@
+from manimlib.imports import *
+
+class GradOfScalarFunc(ThreeDScene):
+
+ CONFIG = {
+ "axes_config": {
+ "x_min": -3,
+ "x_max": 3,
+ "y_min": -3,
+ "y_max": 3,
+ "z_min": 0,
+ "z_max": 3,
+ "a":-3 ,"b": 3, "c":-3 , "d":3,
+ "axes_shift": ORIGIN+IN+LEFT,
+ "x_axis_config": {
+ "tick_frequency": 1,
+ # "include_tip": False,
+ },
+ "y_axis_config": {
+ "tick_frequency": 1,
+ # "include_tip": False,
+ },
+ "z_axis_config": {
+ "tick_frequency": 1,
+ # "include_tip": False,
+ },
+ "num_axis_pieces": 1,
+ },
+ "default_graph_style": {
+ "stroke_width": 2,
+ "stroke_color": WHITE,
+ },
+ "default_vector_field_config": {
+ "delta_x": .5,
+ "delta_y": .5,
+ "x_min": -3,
+ "x_max": 3,
+ "y_min": -3,
+ "y_max": 3,
+ "min_magnitude": 0,
+ "max_magnitude": 2,
+ "colors": [BLUE,GREEN,GREEN,ORANGE,RED],
+ "length_func": lambda norm : .45*sigmoid(norm),
+ "opacity": 1.0,
+ "vector_config": {
+ "stroke_width":6
+ },
+ },
+ "default_surface_config": {
+ "fill_opacity": 0.5,
+ "checkerboard_colors": [BLUE_D],
+ "stroke_width": .5,
+ "stroke_color": WHITE,
+ "stroke_opacity": 0.2,
+ },
+ }
+
+
+ def construct(self):
+
+ self.setup_axes()
+ axes=self.axes
+
+ self.set_camera_orientation(distance=35,
+ phi=80 * DEGREES,
+ theta=-80 * DEGREES,
+ )
+
+ scalar_fn_text=TexMobject("f(x,y)=","\cos(xy)").set_color(BLUE)
+ scalar_fn_text.to_corner(UR,buff=.6)
+
+ operator=TexMobject("\\vec\\nabla").next_to(
+ scalar_fn_text,LEFT,buff=.2
+ ).set_color(GOLD)
+
+ grad_text=TexMobject(r"\dfrac{\partial f}{\partial x} \hat i+\dfrac{\partial f}{\partial y} \hat j+\dfrac{\partial f}{\partial z} \hat k").set_color(GOLD)
+ grad_text.next_to(scalar_fn_text,DOWN).scale(.9)
+
+ VGroup(
+ grad_text[0][1],
+ grad_text[0][9],
+ grad_text[0][17]
+ ).set_color(BLUE)
+ VGroup(
+ grad_text[0][5:8],
+ grad_text[0][13:16],
+ grad_text[0][21:23]
+ ).set_color(WHITE)
+
+ vector_field_text=TexMobject(
+ r"\vec F&=-y\sin(xy)\hat i\\ &-x\sin(xy)\hat j"
+ ).set_color_by_gradient(
+ *self.default_vector_field_config["colors"]
+ )
+ vector_field_text.next_to(scalar_fn_text,DOWN)
+
+
+ '''always generate the scalar field first'''
+ s_field=self.get_scalar_field(
+ func= lambda x ,y : np.cos(x*y/2),
+ dn=.25
+ )
+ v_field=self.get_vector_field(
+ lambda v: np.array([
+ -(v[1]-axes.c2p(0,0,0)[1])*np.sin((v[0]-axes.c2p(0,0,0)[0])*(v[1]-axes.c2p(0,0,0)[1])),
+ -(v[0]-axes.c2p(0,0,0)[0])*np.sin((v[0]-axes.c2p(0,0,0)[0])*(v[1]-axes.c2p(0,0,0)[1])),
+ 0,
+ ]),
+ on_surface=True,
+ )
+
+ self.add_fixed_in_frame_mobjects(scalar_fn_text)
+
+ self.begin_ambient_camera_rotation(rate=.2)
+ self.play(Write(s_field),run_time=2)
+ self.wait(4)
+ self.stop_ambient_camera_rotation()
+
+ self.add_fixed_in_frame_mobjects(operator)
+ self.play(Write(operator),FadeOut(scalar_fn_text[1]))
+ self.add_fixed_in_frame_mobjects(grad_text)
+ self.play(Write(grad_text))
+ self.wait(1.5)
+
+ self.play(FadeOut(grad_text))
+ self.add_fixed_in_frame_mobjects(vector_field_text)
+ show_vec_field=[
+ FadeIn(v_field),
+ Write(vector_field_text),
+ ]
+ # self.play(*show_vec_field,run_time=.5)
+ self.begin_ambient_camera_rotation(rate=.2)
+ self.move_camera(
+ # distance=20,
+ phi=50 * DEGREES,
+ added_anims=show_vec_field,
+ run_time=3
+ )
+
+ self.wait(5)
+ self.stop_ambient_camera_rotation()
+
+ fadeout= [FadeOut(s_field)]
+ # self.play(*fadeout)
+ self.move_camera(
+ # distance=20,
+ phi=0 * DEGREES,
+ theta=-90 * DEGREES,
+ added_anims=fadeout,
+ run_time=2
+ )
+ self.wait(2)
+
+
+
+
+
+ def get_scalar_field(self,func,dn=.5):
+ surface= self.get_surface(
+ lambda x , y:
+ func(x,y),
+ )
+
+ self.surface_points=self.get_points(func,dn)
+ return surface
+
+ def get_points(self,func,dn):
+ axes=self.axes
+
+ x_vals=np.arange(axes.a,axes.b,dn)
+ y_vals=np.arange(axes.c,axes.d,dn)
+ points=[]
+ for x_val in x_vals:
+ for y_val in y_vals:
+ points+=[axes.c2p(x_val,y_val,func(x_val,y_val)+.05)]
+ return points
+
+ def get_vector_field(self,func,on_surface=True,**kwargs):
+ config = dict()
+ config.update(self.default_vector_field_config)
+ config.update(kwargs)
+ vector_field= VectorField(func,**config)
+ vector_field.move_to(self.axes.c2p(0,0,0))
+ self.vector_field=vector_field
+
+ if on_surface:
+ vector_field=self.get_vectors_on_surface()
+
+ return vector_field
+
+
+
+ def get_vectors_on_surface(self):
+ vectors_on_surface = VGroup(*[
+ self.vector_field.get_vector(point)
+ for point in self.surface_points
+ ])
+
+ return vectors_on_surface
+
+
+ def get_surface(self, func, **kwargs):
+ axes=self.axes
+ config = {
+ "u_min": axes.a,
+ "u_max": axes.b,
+ "v_min": axes.c,
+ "v_max": axes.d,
+ "resolution": (
+ 4*(axes.y_max - axes.y_min) // axes.y_axis.tick_frequency,
+ 4*(axes.x_max - axes.x_min) // axes.x_axis.tick_frequency,
+ ),
+ }
+
+ config.update(self.default_surface_config)
+ config.update(kwargs)
+ return ParametricSurface(
+ lambda x,y : axes.c2p(
+ x, y, func(x, y)
+ ),
+ **config
+ )
+
+
+#-------------------------------------------------------
+ #customize 3D axes
+ def get_three_d_axes(self, include_labels=True, include_numbers=False, **kwargs):
+ config = dict(self.axes_config)
+ config.update(kwargs)
+ axes = ThreeDAxes(**config)
+ axes.set_stroke(width=2)
+ self.axes=axes
+
+ if include_numbers:
+ self.add_axes_numbers(axes)
+
+ if include_labels:
+ self.add_axes_labels(axes)
+
+ # Adjust axis orientation
+ axes.x_axis.rotate(
+ -90 * DEGREES, LEFT,
+ about_point=axes.c2p(0, 0, 0),
+ )
+ axes.y_axis.rotate(
+ 90 * DEGREES, UP,
+ about_point=axes.c2p(0, 0, 0),
+ )
+
+ return axes
+
+
+ def setup_axes(self):
+ axes = self.get_three_d_axes(include_labels=True)
+ axes.scale(1)
+ # axes.center()
+ axes.shift(axes.axes_shift)
+
+ self.add(axes)
+ self.axes = axes
+
+ def add_axes_numbers(self, axes):
+ x_axis = axes.x_axis
+ y_axis = axes.y_axis
+ tex_vals_x = [
+
+ ("1", axes.b),
+ ("-1", axes.a),
+ ]
+ tex_vals_y=[
+
+ ("1", axes.d)
+ ]
+ x_labels = VGroup()
+ y_labels = VGroup()
+ for tex, val in tex_vals_x:
+ label = TexMobject(tex)
+ label.scale(1)
+ label.next_to(x_axis.n2p(val), DOWN)
+ # label.rotate(180 * DEGREES)
+ x_labels.add(label)
+ x_axis.add(x_labels)
+ x_axis.numbers = x_labels
+
+ for tex, val in tex_vals_y:
+ label = TexMobject(tex)
+ label.scale(1)
+ label.next_to(y_axis.n2p(val), LEFT)
+ label.rotate(90 * DEGREES)
+ y_labels.add(label)
+
+ y_axis.add(y_labels)
+ y_axis.numbers = y_labels
+
+ return axes
+
+ def add_axes_labels(self, axes):
+ x_label = TexMobject("x")
+ x_label.next_to(axes.x_axis.get_end(), RIGHT)
+ axes.x_axis.label = x_label
+
+ y_label = TextMobject("y")
+ y_label.rotate(90 * DEGREES, OUT)
+ y_label.next_to(axes.y_axis.get_end(), UP)
+ axes.y_axis.label = y_label
+
+ z_label = TextMobject("z")
+ z_label.rotate(90 * DEGREES, RIGHT)
+ z_label.next_to(axes.z_axis.get_zenith(), LEFT)
+ axes.z_axis.label = z_label
+ for axis in axes:
+ axis.add(axis.label)
+ return axes
+
+
+
+ #uploaded by Somnath Pandit. FSF2020_Vector_fields
+
+
+
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/vector-fields/file3_constructing_vector_field.py b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/vector-fields/file3_constructing_vector_field.py
new file mode 100644
index 0000000..fc56306
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/vector-fields/file3_constructing_vector_field.py
@@ -0,0 +1,196 @@
+from manimlib.imports import *
+
+
+class VectorFields(GraphScene):
+ CONFIG = {
+ "x_min" : -4,
+ "x_max" : 4,
+ "y_min" : -4,
+ "y_max" : 4,
+ "graph_origin": ORIGIN+2.5*LEFT,
+ "x_axis_width": 7,
+ "y_axis_height": 7,
+ "x_tick_frequency": 1,
+ "y_tick_frequency": 1,
+ "default_vector_field_config": {
+ "delta_x": .5,
+ "delta_y": .5,
+ "min_magnitude": 0,
+ "max_magnitude": 4,
+ "colors": [GREEN,GREEN,YELLOW,RED],
+ "length_func": lambda n: n/2.5,
+ "opacity": .75,
+ "vector_config": {
+ "stroke_width":6,
+ "max_stroke_width_to_length_ratio":4
+ },
+ },
+
+ "a":-3.5 ,"b": 4, "c": -3.5 ,"d": 4,
+ }
+
+ def construct(self):
+ X = RIGHT*self.x_axis_width/(self.x_max- self.x_min)
+ Y = UP*self.y_axis_height/(self.y_max- self.y_min)
+ self.X=X ;self.Y=Y
+
+ self.setup_axes(animate=False)
+ vector_function = lambda v: np.array([
+ (v[0]-self.graph_origin[0])*(v[1]-self.graph_origin[1]),
+ -(v[0]-self.graph_origin[0]),
+ 0,
+ ])
+
+ vector_field=self.get_vector_field(
+ vector_function,
+ colors= [GREEN]
+ )
+
+ self.show_points()
+ self.wait(.5)
+ self.show_func_machine()
+ self.wait(1)
+ self.produce_vectors(vector_field)
+ self.wait(.5)
+ self.scale_down_vectors(vector_function)
+ self.wait(2)
+
+
+
+ def show_points(self):
+ dn=1
+ x_vals=np.arange(self.a,self.b,dn)
+ y_vals=np.arange(self.c,self.d,dn)
+ dots=VGroup()
+ for x_val in x_vals:
+ for y_val in y_vals:
+ dot=Dot(
+ self.coords_to_point(x_val,y_val),
+ radius=.05,
+ color=TEAL,
+ )
+ dots.add(dot)
+ self.play(ShowCreation(dots, run_time=1))
+ self.dots=dots
+
+ def show_func_machine(self):
+ machine=RoundedRectangle(
+ height=2,
+ width=3.5,
+ color=PURPLE,
+ stroke_width=8
+ ).to_edge(RIGHT, buff=.4)
+
+ machine_label=TexMobject(
+ r"\vec F=xy\hat i-x\hat j",
+ stroke_width=1.5,
+ ).set_color_by_gradient(
+ *self.default_vector_field_config["colors"]
+ ).next_to(machine,IN)
+
+ machine=VGroup(machine,machine_label)
+ self.add(machine)
+
+ self.func_machine=machine
+
+
+ def produce_vectors(self,vector_field):
+ count,i=3,0
+ self.run_time=1
+ non_scaled_vectors=VGroup()
+ for dot in self.dots:
+ if i==count:
+ self.run_time=.05
+ position=dot.get_center()
+ vect= vector_field.get_vector(position)
+ self.go_to_machine(dot)
+ self.take_vec_from_machine(vect,position)
+ non_scaled_vectors.add(vect)
+ i+=1
+
+ self.non_scaled_vectors=non_scaled_vectors
+
+ def go_to_machine(self,dot):
+ if self.run_time>.5:
+ self.play(ApplyMethod(
+ dot.next_to,
+ self.func_machine,4*UP,
+ ),
+ run_time=self.run_time
+ )
+ self.dot=dot
+
+ def take_vec_from_machine(self,vect,position):
+ vect.next_to(self.func_machine,DOWN,buff=.1)
+
+ if self.run_time>.5:
+ point_coord=TexMobject(
+ "(x_i,y_i)"
+ ).next_to(self.dot,RIGHT,buff= .01).scale(.75)
+ input_point=VGroup(point_coord, self.dot)
+ self.play(
+ ApplyMethod(
+ input_point.shift,DOWN,
+ run_time=self.run_time
+ )),
+ self.play(
+ FadeOut(input_point),
+ run_time=.2
+ )
+ self.play(
+ FadeIn(vect),
+ run_time=.4
+ )
+ else:
+ self.remove(self.dot)
+ self.add(vect)
+ self.wait(1.0/15)
+
+ self.play(
+ vect.move_to,position,
+ run_time=self.run_time
+ )
+
+ def scale_down_vectors(self,vector_function):
+ scale_down_text=TextMobject(
+ r"Vectors are rescaled\\ for clarity\\ and \\",
+ r"colors are used to \\ indicate magnitudes",
+ stroke_width=1.2
+ )
+ scale_down_text[0][:7].set_color(BLUE)
+ scale_down_text[1].set_color_by_gradient(
+ *self.default_vector_field_config["colors"]
+ )
+ scale_down_text.to_corner(UR).shift(DOWN)
+ scaled_vector_field= self.get_vector_field(
+ vector_function,
+ length_func= lambda norm : .75*sigmoid(norm)
+ )
+ for vector in self.non_scaled_vectors:
+ scaled_vect= scaled_vector_field.get_vector(vector.get_center())
+ vector.target= scaled_vect
+
+ self.play(FadeOut(self.func_machine))
+ self.play(Write(scale_down_text))
+ self.wait(1.2)
+ self.play(LaggedStartMap(
+ MoveToTarget, self.non_scaled_vectors,
+ run_time=3
+ ))
+
+ def get_vector_field(self,func,**kwargs):
+ config = dict()
+ config.update(self.default_vector_field_config)
+ config.update(kwargs)
+ vector_field= VectorField(func,**config)
+
+ return vector_field
+
+
+
+
+
+#uploaded by Somnath Pandit. FSF2020_Vector_fields
+
+
+
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/vector-fields/file4_slope_field.py b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/vector-fields/file4_slope_field.py
new file mode 100644
index 0000000..8ebb6f5
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/vector-fields/file4_slope_field.py
@@ -0,0 +1,247 @@
+from manimlib.imports import *
+
+
+class SlopeFields(GraphScene):
+ CONFIG = {
+ "x_min" : -2,
+ "x_max" : 2,
+ "y_min" : -2,
+ "y_max" : 2,
+ "graph_origin": ORIGIN+2.5*LEFT,
+ "x_axis_width": 7,
+ "y_axis_height": 7,
+ "x_tick_frequency": 1,
+ "y_tick_frequency": 1,
+ "default_slope_field_config": {
+ "delta_x": .2,
+ "delta_y": .2,
+ "opacity": 1,
+ "color": BLUE_A,
+ "slope_length_factor": .2,
+ "line_config": {
+ "stroke_width":2.5,
+ },
+ },
+
+ "a":-1.9 ,"b": 2, "c": -1.9 ,"d": 2,
+ }
+
+ def construct(self):
+ X = RIGHT*self.x_axis_width/(self.x_max- self.x_min)
+ Y = UP*self.y_axis_height/(self.y_max- self.y_min)
+ self.X=X ;self.Y=Y
+
+ self.setup_axes(animate=False)
+
+ slope_field=self.get_slope_field(
+ lambda x,y:-2.0*(x-self.graph_origin[0])*(y-self.graph_origin[1]),
+ x_min=self.graph_origin[0]+self.a,
+ x_max=self.graph_origin[0]+self.b,
+ y_min=self.graph_origin[1]+self.c,
+ y_max=self.graph_origin[1]+self.d,
+ color= GREEN_B
+ )
+
+ self.show_points()
+ self.wait(.5)
+ self.show_func_machine()
+ self.wait(1)
+ self.produce_slopes(slope_field)
+ # self.add(slope_field)
+ self.glimpse_of_solutions()
+ self.wait(2)
+
+
+
+
+ def show_points(self):
+ dn=1.0/5
+ x_vals=np.arange(self.a,self.b,dn)
+ y_vals=np.arange(self.c,self.d,dn)
+ dots=VGroup()
+ for x_val in x_vals:
+ for y_val in y_vals:
+ dot=Dot(
+ self.coords_to_point(x_val,y_val),
+ radius=.04,
+ color=TEAL,
+ )
+ dots.add(dot)
+ self.play(ShowCreation(dots, run_time=1))
+ self.dots=dots
+
+ def show_func_machine(self):
+ machine=RoundedRectangle(
+ height=3,
+ width=4,
+ color=PURPLE,
+ stroke_width=8
+ ).to_edge(RIGHT, buff=.4)
+
+ machine_label=TextMobject(
+ r"Line segment\\ with slope\\"," $y'=-2xy$",
+ stroke_width=1.2,
+ color=BLUE
+ ).next_to(machine,IN)
+ machine_label[1].set_color(GREEN)
+ machine=VGroup(machine, machine_label)
+ self.play(FadeIn(machine))
+
+ self.func_machine = machine
+
+
+ def produce_slopes(self,slope_field):
+ count,i=3,0
+ self.run_time=1
+ for dot in self.dots:
+ if i==count:
+ self.run_time=.05
+ position=dot.get_center()
+ line= slope_field.get_slope(position)
+ self.go_to_machine(dot)
+ self.take_line_from_machine(line,position)
+ i+=1
+
+ def go_to_machine(self,dot):
+ if self.run_time>.5:
+ self.play(ApplyMethod(
+ dot.next_to,
+ self.func_machine,4*UP,
+ ),
+ run_time=self.run_time
+ )
+ self.dot=dot
+
+ def take_line_from_machine(self,vect,position):
+
+ if self.run_time>.5:
+ vect.next_to(self.func_machine,DOWN,buff=.1)
+ self.play(
+ ApplyMethod(
+ self.dot.shift,DOWN,
+ run_time=self.run_time
+ )),
+ self.play(
+ FadeOut(self.dot),
+ run_time=.2
+ )
+ self.play(
+ FadeIn(vect),
+ run_time=.4
+ )
+ self.play(
+ ApplyMethod(
+ vect.move_to,position
+ ),
+ run_time=self.run_time
+ )
+ else:
+ self.remove(self.dot)
+ self.add(vect)
+ vect.move_to(position)
+
+
+ def get_slope_field(self,func,**kwargs):
+ config = dict()
+ config.update(self.default_slope_field_config)
+ config.update(kwargs)
+ slope_field= SlopeField(func,**config)
+
+ return slope_field
+
+ def glimpse_of_solutions(self):
+ sol_text= TextMobject(
+ r"The solution curves\\ seem to be like...",
+ color= BLUE,
+ stroke_width=1.2
+ )
+ sol_text.to_corner(UR, buff=1)
+ condition_text= TextMobject(
+ r"for different\\ initial conditions",
+ color= GOLD,
+ stroke_width=1.1
+ )
+ condition_text.next_to(sol_text,DOWN,buff=1)
+ solution1 = self.get_graph(
+ lambda x : np.exp(-x**2),
+ x_min = self.a,
+ x_max = self.b,
+ color = PINK)
+ solution2 = self.get_graph(
+ lambda x : .5*np.exp(-x**2),
+ x_min = self.a,
+ x_max = self.b,
+ color = YELLOW)
+ solution3 = self.get_graph(
+ lambda x : 1.5*np.exp(-x**2),
+ x_min = self.a,
+ x_max = self.b,
+ color = BLUE)
+ solution4 = self.get_graph(
+ lambda x : -np.exp(-x**2),
+ x_min = self.a,
+ x_max = self.b,
+ color = RED_E)
+
+ self.play(FadeOut(self.func_machine))
+ self.play(Write(sol_text))
+ self.wait(.6)
+ self.play(ShowCreation(solution1))
+ self.play(Write(condition_text))
+ self.play(ShowCreation(solution2))
+ self.wait(.5)
+ self.play(ShowCreation(solution3))
+ self.wait(.5)
+ self.play(ShowCreation(solution4))
+
+
+class SlopeField(VGroup):
+ CONFIG = {
+ "delta_x": 0.5,
+ "delta_y": 0.5,
+ "x_min": int(np.floor(-FRAME_WIDTH / 2)),
+ "x_max": int(np.ceil(FRAME_WIDTH / 2)),
+ "y_min": int(np.floor(-FRAME_HEIGHT / 2)),
+ "y_max": int(np.ceil(FRAME_HEIGHT / 2)),
+ "opacity": 1.0,
+ "color": WHITE,
+ "slope_length_factor": .25,
+ "line_config": {},
+ }
+
+ def __init__(self, func, **kwargs):
+ VGroup.__init__(self, **kwargs)
+ self.func = func
+
+ x_range = np.arange(
+ self.x_min,
+ self.x_max + self.delta_x,
+ self.delta_x
+ )
+ y_range = np.arange(
+ self.y_min,
+ self.y_max + self.delta_y,
+ self.delta_y
+ )
+ for x, y in it.product(x_range, y_range):
+ point = x * RIGHT + y * UP
+ self.add(self.get_slope(point))
+ self.set_opacity(self.opacity)
+
+ def get_slope(self, point, **kwargs):
+ slope = self.func(*point[:2])
+ line_config = dict(self.line_config)
+ line_config.update(kwargs)
+ line = Line(ORIGIN,self.slope_length_factor*RIGHT, **line_config)
+ line.move_to(point).rotate(np.arctan(slope/3.2))
+
+ line.set_color(self.color)
+ return line
+
+
+
+
+#uploaded by Somnath Pandit. FSF2020_Vector_fields
+
+
+
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/vector-fields/gifs/file1_vector_fields.gif b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/vector-fields/gifs/file1_vector_fields.gif
new file mode 100644
index 0000000..96e50ac
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/vector-fields/gifs/file1_vector_fields.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/vector-fields/gifs/file2_grad_of_scalar_function.gif b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/vector-fields/gifs/file2_grad_of_scalar_function.gif
new file mode 100644
index 0000000..c1ab66a
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/vector-fields/gifs/file2_grad_of_scalar_function.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/vector-fields/gifs/file3_constructing_vector_field.gif b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/vector-fields/gifs/file3_constructing_vector_field.gif
new file mode 100644
index 0000000..6a57cab
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/vector-fields/gifs/file3_constructing_vector_field.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/vector-fields/gifs/file4_slope_field.gif b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/vector-fields/gifs/file4_slope_field.gif
new file mode 100644
index 0000000..c39ec54
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/vector-fields/gifs/file4_slope_field.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/README.md b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/README.md
index e69de29..97a0fb7 100644
--- a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/README.md
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/README.md
@@ -0,0 +1,9 @@
+# Contributer: Nishan Poojary
+Github Account : <a href="https://github.com/nishanpoojary">nishanpoojary</a>
+<br/></br>
+## Sub-Topics Covered:
++ Scalar Functions
++ Multivariable Functions
++ Multivariable Limits and Continuity
++ Partial Derivatives
++ Directonal Derivatives
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/directional-derivatives/README.md b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/directional-derivatives/README.md
new file mode 100644
index 0000000..a62369d
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/directional-derivatives/README.md
@@ -0,0 +1,8 @@
+**file1_directional_deriv**
+![file1_directional_deriv](https://github.com/nishanpoojary/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/directional-derivatives/gifs/file1_directional_deriv.gif)
+
+**file2_gradient**
+![file2_gradient](https://github.com/nishanpoojary/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/directional-derivatives/gifs/file2_gradient.gif)
+
+**file3_gradient_level_curves**
+![file3_gradient_level_curves](https://github.com/nishanpoojary/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/directional-derivatives/gifs/file3_gradient_level_curves.gif)
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/directional-derivatives/file1_directional_deriv.py b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/directional-derivatives/file1_directional_deriv.py
new file mode 100644
index 0000000..677d821
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/directional-derivatives/file1_directional_deriv.py
@@ -0,0 +1,85 @@
+from manimlib.imports import *
+
+class GeomRepresen(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes()
+
+ paraboloid = ParametricSurface(
+ lambda u, v: np.array([
+ 3*np.sin(u)*np.cos(v),
+ 3*np.sin(u)*np.sin(v),
+ -0.25*3*3*np.sin(u)*np.sin(u)+2
+ ]),u_min=0,u_max=PI/4,v_min=0,v_max=2*PI, color = BLUE_C, fill_color = BLUE_C, fill_opacity = 0.7,
+ resolution=(15, 32)).scale(1)
+
+ parabola_curve = ParametricFunction(
+ lambda u : np.array([
+ u,
+ -u,
+ -0.5*(u*u)+2
+ ]),color=PINK,t_min=-1.5,t_max=1.5,
+ )
+
+ circle = Circle(radius = 2.22 , color = BLACK, fill_color = BLUE_C, fill_opacity= 0.3, stroke_width=0.1)
+
+ plane = Polygon(np.array([2.5,-2.5,0]),np.array([-2.5,2.5,0]),np.array([-2.5,2.5,2.5]),np.array([2.5,-2.5,2.5]),np.array([2.5,-2.5,0]), color = BLACK, fill_color = PINK, fill_opacity= 0.2, stroke_width=0.1)
+
+ line = DashedLine(np.array([1,-1,0]), np.array([1,-1,1.5]), color = YELLOW_C)
+
+ tangent_line = Line(np.array([1.5,-1.5,1]), np.array([0.5,-0.5,2]), color = RED_C)
+
+ vector = Arrow(np.array([1,-1,0]), np.array([0.5,-0.5,0]), buff=0.01, color = GREEN_C)
+
+ dot1 =Sphere(radius=0.08).move_to(np.array([1,-1,0])).set_fill(YELLOW_C)
+ dot2 =Sphere(radius=0.08).move_to(np.array([1,-1,1.5])).set_fill(YELLOW_C)
+
+ dot1_lab = TextMobject(r"$P_0$").scale(0.6).move_to(np.array([1,-1,1.8])).set_color(RED_C)
+ dot2_lab = TextMobject(r"$(x_0,y_0)$").scale(0.6).move_to(np.array([1.6,-1,0])).set_color(PURPLE)
+ vector_lab = TextMobject(r"$\hat{u}$").scale(0.8).move_to(np.array([1.2,-0.5,0])).set_color(GREEN_C)
+ domain_lab = TextMobject(r"$D$").scale(0.6).move_to(np.array([1,1,0])).set_color(GREEN_C)
+ func_lab = TextMobject(r"$z = f(x,y)$").scale(0.6).move_to(1*UP + 2.8*RIGHT).set_color(BLUE_C)
+ directional_deriv_lab = TextMobject(r"Slope = $D_{\hat{u}}f(x_0,y_0)$").scale(0.6).move_to(2.2*UP + 1.5*RIGHT).set_color(YELLOW_C)
+
+ self.add(axes)
+
+ axis = TextMobject(r"X",r"Y",r"Z")
+ axis[0].move_to(6*RIGHT)
+ axis[1].move_to(6*UP)
+ axis[2].move_to(np.array([0,0,3.7]))
+
+ self.add_fixed_orientation_mobjects(axis[2])
+ self.add_fixed_orientation_mobjects(axis[0])
+ self.add_fixed_orientation_mobjects(axis[1])
+
+ self.set_camera_orientation(phi=65 * DEGREES, theta = 20*DEGREES)
+
+ self.play(ShowCreation(paraboloid))
+ self.add_fixed_in_frame_mobjects(func_lab)
+ self.wait()
+
+ #self.play(ShowCreation(circle))
+ self.bring_to_front(circle)
+ self.wait()
+ self.add_fixed_orientation_mobjects(domain_lab)
+ self.wait()
+
+ self.play(ShowCreation(plane), ShowCreation(parabola_curve))
+ self.play(ShowCreation(dot1), GrowArrow(line), ShowCreation(dot2))
+ self.add_fixed_orientation_mobjects(dot1_lab)
+ self.wait()
+ self.add_fixed_orientation_mobjects(dot2_lab)
+ self.wait()
+
+ self.play(ShowCreation(tangent_line))
+ self.add_fixed_in_frame_mobjects(directional_deriv_lab)
+ self.wait()
+
+ self.play(GrowArrow(vector))
+ self.add_fixed_orientation_mobjects(vector_lab)
+ self.wait()
+
+
+ self.begin_ambient_camera_rotation(rate=0.1)
+ self.wait(3)
+
+
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/directional-derivatives/file2_gradient.py b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/directional-derivatives/file2_gradient.py
new file mode 100644
index 0000000..e9fef50
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/directional-derivatives/file2_gradient.py
@@ -0,0 +1,103 @@
+from manimlib.imports import *
+
+class Gradient(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes() # creates a 3D Axis
+
+
+ quadrant = ParametricSurface(
+ lambda u, v: np.array([
+ 2*np.sin(u)*np.cos(v),
+ 2*np.sin(u)*np.sin(v),
+ 2*np.cos(u)
+ ]),u_min=0,u_max=PI/3,v_min=0,v_max=PI/2,checkerboard_colors=[GREEN_C, GREEN_E],
+ resolution=(15, 32)).scale(1)
+
+ quadrant_curve = ParametricSurface(
+ lambda u, v: np.array([
+ 2*np.sin(u)*np.cos(v),
+ 2*np.sin(u)*np.sin(v),
+ 2*np.cos(u)
+ ]),u_min=34*DEGREES,u_max=38*DEGREES,v_min=0,v_max=PI/2,checkerboard_colors=[YELLOW_C, YELLOW_E],
+ resolution=(15, 32)).scale(1)
+
+
+
+ dot1 =Sphere(radius=0.05).move_to(np.array([1,1,0])).set_fill(YELLOW_C)
+ dot2 =Sphere(radius=0.05).move_to(np.array([1,1,1.732])).set_fill(YELLOW_C)
+
+ dot1_line = DashedLine(np.array([1,1,1.732]), np.array([0,2,2]), color = WHITE)
+ dot1_lab = TextMobject(r"$P_0(x_0,y_0,z_0)$").move_to(np.array([0,2.1,2.2])).set_color(YELLOW_C).scale(0.6)
+ #dot2_line = Line(np.array([0.8,0.8,0]), np.array([1,0.6,0]), color = PINK)
+
+ positive_vector = Arrow(np.array([1,1,0]), np.array([0.5,0.5,0]), buff=0.001, color = BLUE_C)
+ positive_gradient = Arrow(np.array([1,1,1.732]), np.array([0.5,0.5,1.9362]), buff=0.001, color = BLUE_C)
+ positive_gradient_lab = TextMobject(r"$\nabla f$").move_to(np.array([0.5,0.3,0])).set_color(BLUE_C).scale(0.5)
+
+ negative_vector = Arrow(np.array([1,1,0]), np.array([1.5,1.5,0]), buff=0.001, color = RED_C)
+ negative_gradient = Arrow(np.array([1,1,1.732]), np.array([1.5,1.5,1.322]), buff=0.001, color = RED_C)
+ negative_gradient_lab = TextMobject(r"$-\nabla f$").move_to(np.array([1.6,1.6,0])).set_color(RED_C).scale(0.5)
+
+ positive_vector_line = DashedLine(np.array([0.8,0.8,0]), np.array([1,-2,0]), color = WHITE)
+ positive_vector_lab = TextMobject(r"Most Rapid increase in $f$").move_to(np.array([1.6,-3.6,0])).set_color(BLUE_C).scale(0.6)
+ negative_vector_line = DashedLine(np.array([1.2,1.2,0]), np.array([3,-1.5,0]), color = WHITE)
+ negative_vector_lab = TextMobject(r"Most Rapid decrease in $f$").move_to(np.array([3.6,-3,0])).set_color(RED_C).scale(0.6)
+
+
+
+ line1 = DashedLine(np.array([0.5,0.5,0]), np.array([0.5,0.5,1.9362]), color = BLUE_C)
+ line2 = DashedLine(np.array([1,1,0]), np.array([1,1,1.732]), color = YELLOW_C)
+ line3 = DashedLine(np.array([1.5,1.5,0]), np.array([1.5,1.5,1.322]), color = RED_C)
+
+ curve_vector1 = Arrow(np.array([1,1,0]), np.array([1.5,0.5,0]), buff=0.001, color = YELLOW_C)
+ curve_vector2 = Arrow(np.array([1,1,0]), np.array([0.5,1.5,0]), buff=0.001, color = YELLOW_C)
+
+ curve_vector1_line = DashedLine(np.array([1.2,0.8,0]), np.array([1,2.5,0]), color = WHITE)
+ curve_vector2_line = DashedLine(np.array([0.8,1.2,0]), np.array([1,2.5,0]), color = WHITE)
+ curve_vector_lab = TextMobject(r"Zero Change in $f$").move_to(np.array([0.7,3.6,0])).set_color(PINK).scale(0.6)
+
+ #square = Square(side_length = 0.5).rotate(45*DEGREES).move_to(np.array([1.025,0.975,0]))
+ line_x = Line(np.array([0.8,0.8,0]), np.array([1,0.6,0]), color = PINK)
+ line_y = Line(np.array([1.2,0.8,0]), np.array([1,0.6,0]), color = PINK)
+
+ ninety_degree = VGroup(line_x, line_y)
+
+ self.set_camera_orientation(phi=60* DEGREES, theta = 20*DEGREES)
+
+ self.add(axes)
+
+ axis = TextMobject(r"X",r"Y",r"Z")
+ axis[0].move_to(6*RIGHT)
+ axis[1].move_to(6*UP)
+ axis[2].move_to(np.array([0,0,3.7]))
+
+ self.add_fixed_orientation_mobjects(axis[2])
+ self.add_fixed_orientation_mobjects(axis[0])
+ self.add_fixed_orientation_mobjects(axis[1])
+
+ self.play(ShowCreation(quadrant))
+ self.wait()
+ self.play(ShowCreation(dot1), ShowCreation(dot2))
+ self.wait()
+ self.play(GrowArrow(positive_vector), GrowArrow(positive_gradient))
+ self.wait()
+ self.play(GrowArrow(negative_vector), GrowArrow(negative_gradient))
+ self.wait()
+ self.play(GrowArrow(line1), GrowArrow(line2), GrowArrow(line3))
+ self.wait()
+ self.play(ShowCreation(quadrant_curve))
+ self.wait()
+ self.play(GrowArrow(curve_vector1), GrowArrow(curve_vector2), ShowCreation(ninety_degree))
+ self.wait()
+ self.play(GrowArrow(dot1_line))
+ self.add_fixed_orientation_mobjects(dot1_lab)
+ self.wait()
+ self.play(GrowArrow(curve_vector1_line), GrowArrow(curve_vector2_line))
+ self.add_fixed_orientation_mobjects(curve_vector_lab)
+ self.wait()
+ self.add_fixed_orientation_mobjects(positive_gradient_lab, negative_gradient_lab)
+ self.wait()
+ self.play(GrowArrow(positive_vector_line), GrowArrow(negative_vector_line))
+ self.add_fixed_orientation_mobjects(positive_vector_lab, negative_vector_lab)
+ self.begin_ambient_camera_rotation(rate=0.1)
+ self.wait(3) \ No newline at end of file
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/directional-derivatives/file3_gradient_level_curves.py b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/directional-derivatives/file3_gradient_level_curves.py
new file mode 100644
index 0000000..a3b88e5
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/directional-derivatives/file3_gradient_level_curves.py
@@ -0,0 +1,107 @@
+from manimlib.imports import *
+
+class GradientLevelCurves(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes()
+
+ paraboloid = ParametricSurface(
+ lambda u, v: np.array([
+ u*np.cos(v),
+ u*np.sin(v),
+ -u*u+2
+ ]),u_min=-1.414,u_max=1.414,v_min=0,v_max=2*PI, color = BLUE_C, fill_color = BLUE_C, fill_opacity = 0.1,
+ resolution=(15, 32)).scale(1)
+
+ plane_0 = Polygon(np.array([2,-2,0]),np.array([2,2,0]),np.array([-2,2,0]),np.array([-2,-2,0]),np.array([2,-2,0]), color = BLUE_E, fill_color = BLUE_E, fill_opacity = 0.3)
+ plane_0_lab = TextMobject("C = 0").move_to(0.4*UP+3.2*RIGHT).set_color(BLUE_E).scale(0.6)
+ circle_0 = Circle(radius = 1.414 , color = BLUE_E)
+ circle_0_lab = TextMobject("0").move_to(1.1*DOWN+1.1*RIGHT).set_color(BLUE_E).scale(0.6)
+
+ plane_0_5 = Polygon(np.array([2,-2,0.5]),np.array([2,2,0.5]),np.array([-2,2,0.5]),np.array([-2,-2,0.5]),np.array([2,-2,0.5]), color = GREEN_C, fill_color = GREEN_C, fill_opacity = 0.3)
+ plane_0_5_lab = TextMobject("C = 0.5").move_to(0.8*UP+3.4*RIGHT).set_color(GREEN_C).scale(0.6)
+ circle_0_5 = Circle(radius = 1.224 , color = GREEN_C)
+ circle_0_5_lab = TextMobject("0.5").move_to(0.9*DOWN+0.9*RIGHT).set_color(GREEN_C).scale(0.6)
+ circle_0_5_copy = circle_0_5.copy().move_to(np.array([0,0,0.5]))
+
+ plane_1 = Polygon(np.array([2,-2,1]),np.array([2,2,1]),np.array([-2,2,1]),np.array([-2,-2,1]),np.array([2,-2,1]), color = YELLOW_C, fill_color = YELLOW_C, fill_opacity = 0.3)
+ plane_1_lab = TextMobject("C = 1").move_to(1.2*UP+3.3*RIGHT).set_color(YELLOW_C).scale(0.6)
+ circle_1 = Circle(radius = 1 , color = YELLOW_C)
+ circle_1_lab = TextMobject("1").move_to(0.7*DOWN+0.7*RIGHT).set_color(YELLOW_C).scale(0.6)
+ circle_1_copy = circle_1.copy().move_to(np.array([0,0,1]))
+
+ plane_1_5 = Polygon(np.array([2,-2,1.5]),np.array([2,2,1.5]),np.array([-2,2,1.5]),np.array([-2,-2,1.5]),np.array([2,-2,1.5]), color = ORANGE, fill_color = ORANGE, fill_opacity = 0.3)
+ plane_1_5_lab = TextMobject("C = 1.5").move_to(1.7*UP+3.4*RIGHT).set_color(ORANGE).scale(0.6)
+ circle_1_5 = Circle(radius = 0.707 , color = ORANGE)
+ circle_1_5_lab = TextMobject("1.5").move_to(0.5*DOWN+0.5*RIGHT).set_color(ORANGE).scale(0.6)
+ circle_1_5_copy = circle_1_5.copy().move_to(np.array([0,0,1.5]))
+
+ plane_2 = Polygon(np.array([2,-2,2]),np.array([2,2,2]),np.array([-2,2,2]),np.array([-2,-2,2]),np.array([2,-2,2]), color = RED_C, fill_color = RED_C, fill_opacity = 0.3)
+ plane_2_lab = TextMobject("C = 2").move_to(2.1*UP+3.3*RIGHT).set_color(RED_C).scale(0.6)
+ dot_2 = Dot().set_fill(RED_C)
+ circle_2_lab = TextMobject("2").move_to(0.2*DOWN+0.2*RIGHT).set_color(RED_C).scale(0.6)
+ dot_2_copy = dot_2.copy().move_to(np.array([0,0,2]))
+
+ vector1 = Arrow(np.array([0.99,-0.99,0]), np.array([0.865,-0.865,0.5]), buff=0.01, color = RED_C).set_stroke(width=3)
+ gradient1 = Arrow(np.array([0.99,-0.99,0]), np.array([0.865,-0.865,0]), buff=0.01, color = RED_C).set_stroke(width=3)
+
+ vector2 = Arrow(np.array([0.865,-0.865,0.5]), np.array([0.707,-0.707,1]), buff=0.01, color = RED_C).set_stroke(width=3)
+ gradient2 = Arrow(np.array([0.865,-0.865,0]), np.array([0.707,-0.707,0]), buff=0.01, color = RED_C).set_stroke(width=3)
+
+ vector3 = Arrow(np.array([0.707,-0.707,1]), np.array([0.499,-0.499,1.5]), buff=0.01, color = RED_C).set_stroke(width=3)
+ gradient3 = Arrow(np.array([0.707,-0.707,0]), np.array([0.499,-0.499,0]), buff=0.01, color = RED_C).set_stroke(width=3)
+
+ vector4 = Arrow(np.array([0.499,-0.499,1.5]), np.array([0,0,2]), buff=0.01, color = RED_C).set_stroke(width=3)
+ gradient4 = Arrow(np.array([0.499,-0.499,0]), np.array([0,0,0]), buff=0.01, color = RED_C).set_stroke(width=3)
+
+
+ self.set_camera_orientation(phi=80 * DEGREES, theta = 0*DEGREES)
+ #self.set_camera_orientation(phi=45 * DEGREES, theta = -20*DEGREES)
+
+ self.add(axes)
+
+ axis = TextMobject(r"X",r"Y",r"Z")
+ axis[0].move_to(6*RIGHT)
+ axis[1].move_to(6*UP)
+ axis[2].move_to(np.array([0,0,3.7]))
+
+ self.add_fixed_orientation_mobjects(axis[2])
+ self.add_fixed_orientation_mobjects(axis[0])
+ self.add_fixed_orientation_mobjects(axis[1])
+
+ self.play(Write(paraboloid))
+ self.wait()
+ self.play(ShowCreation(plane_0), ShowCreation(circle_0))
+ self.add_fixed_in_frame_mobjects(plane_0_lab)
+ self.wait()
+ self.play(ShowCreation(plane_0_5), ShowCreation(circle_0_5_copy), ShowCreation(circle_0_5))
+ self.add_fixed_in_frame_mobjects(plane_0_5_lab)
+ self.wait()
+ self.play(ShowCreation(plane_1), ShowCreation(circle_1_copy), ShowCreation(circle_1))
+ self.add_fixed_in_frame_mobjects(plane_1_lab)
+ self.wait()
+ self.play(ShowCreation(plane_1_5), ShowCreation(circle_1_5_copy), ShowCreation(circle_1_5))
+ self.add_fixed_in_frame_mobjects(plane_1_5_lab)
+ self.wait()
+ self.play(ShowCreation(plane_2), ShowCreation(dot_2_copy), ShowCreation(dot_2))
+ self.add_fixed_in_frame_mobjects(plane_2_lab)
+ self.wait()
+ self.move_camera(phi=60 * DEGREES, theta = 30*DEGREES,run_time=3)
+ self.play(FadeOut(plane_0), FadeOut(plane_0_lab), FadeOut(plane_0_5), FadeOut(plane_0_5_lab), FadeOut(plane_1), FadeOut(plane_1_lab), FadeOut(plane_1_5), FadeOut(plane_1_5_lab), FadeOut(plane_2), FadeOut(plane_2_lab))
+ self.play(FadeOut(circle_0_5_copy), FadeOut(circle_1_copy), FadeOut(circle_1_5_copy), FadeOut(dot_2_copy))
+
+ self.move_camera(phi=45 * DEGREES, theta = -20*DEGREES,run_time=3)
+ self.play(Write(vector1), Write(gradient1))
+ self.wait()
+ self.play(Write(vector2), Write(gradient2))
+ self.wait()
+ self.play(Write(vector3), Write(gradient3))
+ self.wait()
+ self.play(Write(vector4), Write(gradient4))
+ self.wait()
+ self.move_camera(phi=0 * DEGREES, theta = 0*DEGREES,run_time=3)
+ self.play(FadeOut(paraboloid))
+ self.play(FadeOut(vector1), FadeOut(vector2), FadeOut(vector3), FadeOut(vector4))
+ self.wait()
+ self.add_fixed_in_frame_mobjects(circle_0_lab, circle_0_5_lab, circle_1_lab, circle_1_5_lab,circle_2_lab)
+ self.wait(4)
+ \ No newline at end of file
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/directional-derivatives/gifs/file1_directional_deriv.gif b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/directional-derivatives/gifs/file1_directional_deriv.gif
new file mode 100644
index 0000000..39305d5
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/directional-derivatives/gifs/file1_directional_deriv.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/directional-derivatives/gifs/file2_gradient.gif b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/directional-derivatives/gifs/file2_gradient.gif
new file mode 100644
index 0000000..d96f330
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/directional-derivatives/gifs/file2_gradient.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/directional-derivatives/gifs/file3_gradient_level_curves.gif b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/directional-derivatives/gifs/file3_gradient_level_curves.gif
new file mode 100644
index 0000000..f1bf06a
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/directional-derivatives/gifs/file3_gradient_level_curves.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/Multivariable_Functions_Quiz.pdf b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/Multivariable_Functions_Quiz.pdf
new file mode 100644
index 0000000..7895843
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/Multivariable_Functions_Quiz.pdf
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/README.md b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/README.md
new file mode 100644
index 0000000..0e6e8d3
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/README.md
@@ -0,0 +1,17 @@
+**file1_multivar_func_examples**
+![file1_multivar_func_examples](https://github.com/nishanpoojary/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/gifs/file1_multivar_func_examples.gif)
+
+**file2_multivariable_func_respresentation**
+![file2_multivariable_func_respresentation](https://github.com/nishanpoojary/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/gifs/file2_multivariable_func_respresentation.gif)
+
+**file3_sphere**
+![file3_sphere](https://github.com/nishanpoojary/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/gifs/file3_sphere.gif)
+
+**file4_vectorvf_sine**
+![file4_vectorvf_sine](https://github.com/nishanpoojary/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/gifs/file4_vectorvf_sine.gif)
+
+**file5_vectorvf_helix**
+![file5_vectorvf_helix](https://github.com/nishanpoojary/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/gifs/file5_vectorvf_helix.gif)
+
+**file6_derivative_vectorvf**
+![file6_derivative_vectorvf](https://github.com/nishanpoojary/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/gifs/file6_derivative_vectorvf.gif)
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/file1_multivar_func_examples.py b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/file1_multivar_func_examples.py
new file mode 100644
index 0000000..55b2b7e
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/file1_multivar_func_examples.py
@@ -0,0 +1,167 @@
+from manimlib.imports import *
+
+class Examples1(GraphScene):
+ def construct(self):
+
+ rectangle = Rectangle(height = 3, width = 4, color = GREEN)
+ rectangle_area_func = TexMobject("Area", "=", "f(", "Length", ",", "Breadth", ")").scale(0.6)
+ rectangle_area_func[0].set_color(RED_C)
+ rectangle_area_func[2].set_color(ORANGE)
+ rectangle_area_func[3].set_color(YELLOW_C)
+ rectangle_area_func[5].set_color(BLUE_C)
+ rectangle_area_func[6].set_color(ORANGE)
+
+
+ rectangle_area = TexMobject("Area", "=", "Length", "\\times", "Breadth").scale(0.6)
+ rectangle_area[0].set_color(RED_C)
+ rectangle_area[2].set_color(YELLOW_C)
+ rectangle_area[4].set_color(BLUE_C)
+
+
+ square = Square(side_length = 5, color = PURPLE)
+ square_area_func = TexMobject("Area", "=", "f(", "Length", ")")
+ square_area_func[0].set_color(GREEN_C)
+ square_area_func[2].set_color(ORANGE)
+ square_area_func[3].set_color(BLUE_C)
+ square_area_func[4].set_color(ORANGE)
+
+ square_area = TexMobject("Area", "=", "Length^2")
+ square_area[0].set_color(GREEN_C)
+ square_area[2].set_color(BLUE_C)
+
+
+ circle = Circle(radius = 2, color = PINK)
+ circle_area_func = TexMobject("Area", "=", "f(", "r", ")")
+ circle_area_func[0].set_color(YELLOW_C)
+ circle_area_func[2].set_color(ORANGE)
+ circle_area_func[3].set_color(GREEN_C)
+ circle_area_func[4].set_color(ORANGE)
+
+ circle_area = TexMobject("Area", "=", "\\pi", "r^2")
+ circle_area[0].set_color(YELLOW_C)
+ circle_area[2].set_color(BLUE_C)
+ circle_area[3].set_color(GREEN_C)
+
+ radius = Line(ORIGIN,2*RIGHT, color = RED_C)
+
+
+
+ braces_rect1 = Brace(rectangle, LEFT)
+ eq_text1 = braces_rect1.get_text("Length").set_color(YELLOW_C)
+ braces_rect2 = Brace(rectangle, UP)
+ eq_text2 = braces_rect2.get_text("Breadth").set_color(BLUE_C)
+
+ braces_square = Brace(square, LEFT)
+ braces_square_text = braces_square.get_text("Length").set_color(BLUE_C)
+
+ radius_text = TexMobject("r", color = GREEN_C).next_to(radius,UP)
+
+
+
+ self.play(ShowCreation(rectangle))
+ self.wait(1)
+ self.play(GrowFromCenter(braces_rect1),Write(eq_text1),GrowFromCenter(braces_rect2),Write(eq_text2))
+ self.wait(1)
+ self.play(Write(rectangle_area_func))
+ self.wait(1)
+ self.play(Transform(rectangle_area_func, rectangle_area))
+ self.wait(1)
+ self.play(FadeOut(braces_rect1),FadeOut(eq_text1),FadeOut(braces_rect2),FadeOut(eq_text2),FadeOut(rectangle_area_func))
+
+
+ self.play(Transform(rectangle, square))
+ self.wait(1)
+ self.play(GrowFromCenter(braces_square),Write(braces_square_text))
+ self.wait(1)
+ self.play(Write(square_area_func))
+ self.wait(1)
+ self.play(Transform(square_area_func, square_area))
+ self.wait(1)
+ self.play(FadeOut(braces_square),FadeOut(braces_square_text),FadeOut(square_area_func))
+
+
+ self.play(Transform(rectangle, circle))
+ self.wait(1)
+ self.play(ShowCreation(radius),Write(radius_text))
+ self.wait(1)
+ self.play(FadeOut(radius_text),FadeOut(radius))
+ self.wait(1)
+ self.play(Write(circle_area_func))
+ self.wait(1)
+ self.play(Transform(circle_area_func, circle_area))
+ self.wait(1)
+ self.play(FadeOut(circle_area_func))
+
+
+
+class Examples2(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes()
+
+ rectangle_x_y_0 = Polygon(np.array([-1,-2,0]),np.array([-1,2,0]),np.array([1,2,0]),np.array([1,-2,0]),np.array([-1,-2,0]), color = RED_E, fill_color = RED_C, fill_opacity = 0.1)
+ rectangle_x_y_3 = Polygon(np.array([-1,-2,3]),np.array([-1,2,3]),np.array([1,2,3]),np.array([1,-2,3]),np.array([-1,-2,3]), color = RED_E, fill_color = RED_C, fill_opacity = 0.1)
+
+ rectangle_y_z_1 = Polygon(np.array([1,-2,3]),np.array([1,2,3]),np.array([1,2,0]),np.array([1,-2,0]),np.array([1,-2,3]), color = RED_E, fill_color = RED_C, fill_opacity = 0.1)
+ rectangle_y_z_minus_1 = Polygon(np.array([-1,-2,3]),np.array([-1,2,3]),np.array([-1,2,0]),np.array([-1,-2,0]),np.array([-1,-2,3]), color = RED_E, fill_color = RED_C, fill_opacity = 0.1)
+
+ rectangle_x_z_2 = Polygon(np.array([1,2,3]),np.array([-1,2,3]),np.array([-1,2,0]),np.array([1,2,0]),np.array([1,2,3]), color = RED_E, fill_color = RED_C, fill_opacity = 0.1)
+ rectangle_x_z_minus_2 = Polygon(np.array([1,-2,3]),np.array([-1,-2,3]),np.array([-1,-2,0]),np.array([1,-2,0]),np.array([1,-2,3]), color = RED_E, fill_color = RED_C, fill_opacity = 0.1)
+
+ box = VGroup(rectangle_x_y_0, rectangle_x_y_3, rectangle_y_z_1, rectangle_y_z_minus_1, rectangle_x_z_2, rectangle_x_z_minus_2)
+
+ braces_rectangle_x_y_0 = Line(np.array([1,2,0]), np.array([1,-2,0]), color = BLUE_C)
+ braces_rectangle_x_y_0_text = TextMobject("Length").set_color(BLUE_C).move_to(np.array([2,-1,0]))
+
+ braces_rectangle_y_z_1 = Line(np.array([1,2,0]), np.array([1,2,3]), color = YELLOW_C)
+ braces_rectangle_y_z_1_text = TextMobject("Height").set_color(YELLOW_C).move_to(np.array([2,3.8,2]))
+
+ braces_rectangle_x_z_2 = Line(np.array([1,2,3]), np.array([-1,2,3]), color = PURPLE)
+ braces_rectangle_x_z_2_text = TextMobject("Breadth").set_color(PURPLE).move_to(np.array([0,3.8,3.3]))
+
+ box_area_func = TexMobject("Area =", "f(", "Length", ",", "Breadth", ",", "Height", ")").move_to(4*LEFT+3.5*UP).scale(0.6)
+ box_area_func[0].set_color(GREEN_C)
+ box_area_func[1].set_color(ORANGE)
+ box_area_func[2].set_color(BLUE_C)
+ box_area_func[4].set_color(PURPLE)
+ box_area_func[6].set_color(YELLOW_C)
+ box_area_func[7].set_color(ORANGE)
+
+ box_area_func_2 = TexMobject("Area =", "Length", "\\times", "Breadth", "\\times", "Height").move_to(4*LEFT+3.5*UP).scale(0.6)
+ box_area_func_2[0].set_color(GREEN_C)
+ box_area_func_2[1].set_color(BLUE_C)
+ box_area_func_2[3].set_color(PURPLE)
+ box_area_func_2[5].set_color(YELLOW_C)
+
+
+ self.set_camera_orientation(phi=70 * DEGREES, theta = 45*DEGREES)
+
+ self.add(axes)
+
+ axis = TextMobject(r"X",r"Y",r"Z")
+ axis[0].move_to(6*RIGHT)
+ axis[1].move_to(6*UP)
+ axis[2].move_to(3.7*UP)
+
+ self.add_fixed_in_frame_mobjects(axis[2])
+ self.add_fixed_orientation_mobjects(axis[0])
+ self.add_fixed_orientation_mobjects(axis[1])
+
+ self.play(ShowCreation(box), ShowCreation(braces_rectangle_x_y_0))
+ self.add_fixed_orientation_mobjects(braces_rectangle_x_y_0_text)
+ self.play(ShowCreation(braces_rectangle_y_z_1))
+ self.add_fixed_orientation_mobjects(braces_rectangle_y_z_1_text)
+ self.play(ShowCreation(braces_rectangle_x_z_2))
+ self.add_fixed_orientation_mobjects(braces_rectangle_x_z_2_text)
+ self.wait(2)
+
+ self.move_camera(phi=60* DEGREES,theta=80*DEGREES)
+ self.add_fixed_in_frame_mobjects(box_area_func)
+ self.play(Write(box_area_func))
+ self.wait()
+
+
+ self.play(ReplacementTransform(box_area_func,box_area_func_2))
+ self.add_fixed_in_frame_mobjects(box_area_func_2)
+
+
+ self.wait(3) \ No newline at end of file
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/file2_multivariable_func_respresentation.py b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/file2_multivariable_func_respresentation.py
new file mode 100644
index 0000000..d10ff0a
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/file2_multivariable_func_respresentation.py
@@ -0,0 +1,98 @@
+from manimlib.imports import *
+
+class MultivariableFunc(Scene):
+ def construct(self):
+
+ topic = TextMobject("Multivariable Functions")
+ topic.set_color_by_gradient(RED, ORANGE, YELLOW, GREEN, BLUE, PURPLE)
+ topic.scale(1.5)
+
+ self.play(Write(topic))
+ self.wait()
+ self.play(FadeOut(topic))
+
+
+ #circle = Circle()
+ #circle.scale(3)
+
+ scalar_function = TextMobject("Scalar Valued Function")
+ scalar_function.set_color_by_gradient(RED, ORANGE, YELLOW, GREEN, BLUE, PURPLE)
+ scalar_function.scale(1.5)
+ scalar_function.move_to(2.5*UP)
+
+ rectangle = Rectangle(height = 2, width = 4)
+ rectangle.set_color(PURPLE)
+
+ eqn1 = TextMobject(r"f(x,y) = $x^2y$")
+ eqn1.set_color_by_gradient(RED, ORANGE, YELLOW, GREEN, BLUE)
+
+
+
+ number1 = TextMobject("(2,1)")
+ number1.move_to(2.5*UP+ 4*LEFT)
+ number1.scale(1.2)
+ number1.set_color(ORANGE)
+
+ output1 = TextMobject("4")
+ output1.scale(1.5)
+ output1.set_color(BLUE_C)
+ output1.move_to(3*RIGHT)
+
+ eqn1_1 = TextMobject(r"f(2,1) = $2^2(1)$")
+ eqn1_1.set_color_by_gradient(RED, ORANGE, YELLOW, GREEN, BLUE)
+
+
+ self.play(Write(eqn1),ShowCreation(rectangle))
+ self.wait()
+ self.play(ApplyMethod(number1.move_to, 3*LEFT))
+ self.play(FadeOut(number1))
+ self.play(Transform(eqn1, eqn1_1))
+ self.wait()
+ self.play(ApplyMethod(output1.move_to, 2.5*DOWN+4*RIGHT))
+ self.wait()
+ self.play(Write(scalar_function))
+ self.play(FadeOut(output1), FadeOut(scalar_function), FadeOut(eqn1))
+
+
+ vector_function = TextMobject("Vector Valued Function")
+ vector_function.set_color_by_gradient(RED, ORANGE, YELLOW, GREEN, BLUE, PURPLE)
+ vector_function.scale(1.5)
+ vector_function.move_to(2.5*UP)
+
+
+ eqn2 = TextMobject(r"f(x,y,z) = $ \begin{bmatrix} x^2y \\ 2yz \end{bmatrix}$")
+ eqn2.set_color_by_gradient(RED, ORANGE, YELLOW, GREEN, BLUE, PURPLE)
+
+ number2 = TextMobject("(2,1,3)")
+ number2.move_to(2.5*UP+ 4*LEFT)
+ number2.scale(1.2)
+ number2.set_color(ORANGE)
+
+ output2 = TextMobject(r"$ \begin{bmatrix} 4 \\ 6 \end{bmatrix}$")
+ #output2.scale(1.5)
+ output2.set_color(BLUE_C)
+ output2.move_to(3*RIGHT)
+
+ #eqn2_1 = TextMobject(r"f(2,1,3) = $2^2(1) + 2(1)(3)$")
+ #eqn2_1.set_color(YELLOW)
+
+ #eqn2_2 = TextMobject(r"f(2,1,3) = $2 + 6$")
+ #eqn2_2.set_color(YELLOW)
+
+
+ self.play(Write(eqn2))
+
+ self.wait()
+ self.play(ApplyMethod(number2.move_to, 3*LEFT))
+ self.play(FadeOut(number2))
+
+ #self.play(Transform(eqn2, eqn2_1))
+ #self.wait(1)
+ #self.play(Transform(eqn2, eqn2_2))
+ #self.wait(1)
+
+ self.play(ApplyMethod(output2.move_to, 2.5*DOWN+4*RIGHT))
+ self.wait()
+ self.play(Write(vector_function))
+ self.play(FadeOut(output2),FadeOut(eqn2), FadeOut(vector_function), FadeOut(rectangle))
+ self.wait() \ No newline at end of file
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/file3_sphere.py b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/file3_sphere.py
new file mode 100644
index 0000000..86239ae
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/file3_sphere.py
@@ -0,0 +1,177 @@
+from manimlib.imports import *
+
+class Sphere(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes() # creates a 3D Axis
+
+ text3d = TextMobject(r"$f(x,y) \rightarrow Point(x,y,z)$")
+ text3d1 = TextMobject(r"$f(x,y) \rightarrow Point(x,y, \sqrt{r^2 - x^2 - y^2})$")
+ self.add_fixed_in_frame_mobjects(text3d)
+ text3d.scale(0.7)
+ text3d1.scale(0.7)
+ text3d.to_corner(UL)
+ text3d1.to_corner(UL)
+ text3d.set_color_by_gradient(RED, ORANGE, YELLOW, GREEN, BLUE, PURPLE)
+ text3d1.set_color_by_gradient(RED, ORANGE, YELLOW, GREEN, BLUE, PURPLE)
+ self.play(Write(text3d))
+ self.wait(1)
+
+ self.play(Transform(text3d,text3d1))
+ self.add_fixed_in_frame_mobjects(text3d1)
+ self.play(FadeOut(text3d))
+
+ sphere = ParametricSurface(
+ lambda u, v: np.array([
+ 2*np.sin(u)*np.cos(v),
+ 2*np.sin(u)*np.sin(v),
+ 2*np.cos(u)
+ ]),u_min=0,u_max=PI,v_min=0,v_max=2*PI,checkerboard_colors=[RED_D, RED_E],
+ resolution=(15, 32)).scale(1)
+
+
+ #Experiment with circles by changing difference value of u and v
+ '''
+ sphere_points = [np.array([2*np.sin(u*DEGREES)*np.cos(v*DEGREES), 2*np.sin(u*DEGREES)*np.sin(v*DEGREES), 2*np.cos(u*DEGREES)]) for u in range(0, 185, 5) for v in range(0, 365, 5)]
+
+ sphere_spheres = [Dot().move_to(pts) for pts in sphere_points]
+
+ sphere = VGroup(*sphere_spheres)
+ '''
+
+ self.set_camera_orientation(phi=75 * DEGREES, theta = 45*DEGREES)
+
+ self.add(axes)
+
+ axis = TextMobject(r"X",r"Y",r"Z")
+ axis[0].move_to(6*RIGHT)
+ axis[1].move_to(6*UP)
+ axis[2].move_to(np.array([0,0,3.7]))
+
+ self.add_fixed_orientation_mobjects(axis[2])
+ self.add_fixed_orientation_mobjects(axis[0])
+ self.add_fixed_orientation_mobjects(axis[1])
+
+ dot_x_y1 = Dot().scale(0.75).set_fill(RED_C).move_to(np.array([-1,1,0]))
+ dot_x_y_z1 = Dot().scale(0.75).set_fill(RED_C).move_to(np.array([-1,1,1.414]))
+ dot_x_y_z_1 = Dot().scale(0.75).set_fill(RED_C).move_to(np.array([-1,1,-1.414]))
+ line1 = DashedLine(np.array([-1,1,-1.414]), np.array([-1,1,1.414]), color = YELLOW_C)
+
+ point_x_y1 = TexMobject("(-1,1,0)").set_color(BLUE_C).move_to(np.array([-1.5,1.5,0])).scale(0.5)
+ point_x_y_z1 = TexMobject("(-1,1,\\sqrt{r^2 - x^2 - y^2})").set_color(BLUE_C).move_to(np.array([-1.5,1.5,1.414])).scale(0.5)
+ point_x_y_z1_2 = TexMobject("(-1,1,\\sqrt{4 - x^2 - y^2})").set_color(BLUE_C).move_to(np.array([-1.5,1.5,1.414])).scale(0.5)
+ point_x_y_z1_3 = TexMobject("(-1,1,\\sqrt{4 - 1 - 1})").set_color(BLUE_C).move_to(np.array([-1.5,1.5,1.414])).scale(0.5)
+ point_x_y_z1_4 = TexMobject("(-1,1,\\sqrt{2})").set_color(BLUE_C).move_to(np.array([-1.5,1.5,1.414])).scale(0.5)
+ point_x_y_z1_5 = TexMobject("(-1,1,1.414)").set_color(BLUE_C).move_to(np.array([-1.5,1.5,1.414])).scale(0.5)
+
+ point_x_y_z_1 = TexMobject("(-1,1,\\sqrt{r^2 - x^2 - y^2})").set_color(BLUE_C).move_to(np.array([-1.5,1.5,-1.414])).scale(0.5)
+ point_x_y_z_1_2 = TexMobject("(-1,1,\\sqrt{4 - x^2 - y^2})").set_color(BLUE_C).move_to(np.array([-1.5,1.5,-1.414])).scale(0.5)
+ point_x_y_z_1_3 = TexMobject("(-1,1,\\sqrt{4 - 1 - 1})").set_color(BLUE_C).move_to(np.array([-1.5,1.5,-1.414])).scale(0.5)
+ point_x_y_z_1_4 = TexMobject("(-1,1,\\sqrt{2})").set_color(BLUE_C).move_to(np.array([-1.5,1.5,-1.414])).scale(0.5)
+ point_x_y_z_1_5 = TexMobject("(-1,1,-1.414)").set_color(BLUE_C).move_to(np.array([-1.5,1.5,-1.414])).scale(0.5)
+
+
+ self.play(ShowCreation(dot_x_y1))
+ self.add_fixed_orientation_mobjects(point_x_y1)
+ self.play(ShowCreation(dot_x_y_z1), ShowCreation(dot_x_y_z_1), ShowCreation(line1))
+ self.add_fixed_orientation_mobjects(point_x_y_z1, point_x_y_z_1)
+ self.wait(0.5)
+ self.play(ReplacementTransform(point_x_y_z1,point_x_y_z1_2), ReplacementTransform(point_x_y_z_1,point_x_y_z_1_2))
+ self.add_fixed_orientation_mobjects(point_x_y_z1_2, point_x_y_z_1_2)
+
+ self.wait(0.5)
+ self.play(ReplacementTransform(point_x_y_z1_2,point_x_y_z1_3), ReplacementTransform(point_x_y_z_1_2,point_x_y_z_1_3))
+ self.add_fixed_orientation_mobjects(point_x_y_z1_3, point_x_y_z_1_3)
+ self.wait(0.5)
+ self.play(ReplacementTransform(point_x_y_z1_3,point_x_y_z1_4), ReplacementTransform(point_x_y_z_1_3,point_x_y_z_1_4))
+ self.add_fixed_orientation_mobjects(point_x_y_z1_4, point_x_y_z_1_4)
+ self.wait(0.5)
+ self.play(ReplacementTransform(point_x_y_z1_4,point_x_y_z1_5), ReplacementTransform(point_x_y_z_1_4,point_x_y_z_1_5))
+ self.add_fixed_orientation_mobjects(point_x_y_z1_5, point_x_y_z_1_5)
+
+
+
+ dot_x_y2 = Dot().scale(0.75).set_fill(RED_C).move_to(np.array([0.5,-0.5,0]))
+ dot_x_y_z2 = Dot().scale(0.75).set_fill(RED_C).move_to(np.array([0.5,-0.5,1.87]))
+ dot_x_y_z_2 = Dot().scale(0.75).set_fill(RED_C).move_to(np.array([0.5,-0.5,-1.87]))
+ line2 = DashedLine(np.array([0.5,-0.5,-1.87]), np.array([0.5,-0.5,1.87]), color = YELLOW_C)
+
+ point_x_y2 = TexMobject("(0.5,-0.5,0)").set_color(BLUE_C).move_to(np.array([1.5,-1.5,0])).scale(0.5)
+ point_x_y_z2 = TexMobject("(0.5,-0.5,\\sqrt{r^2 - x^2 - y^2})").set_color(BLUE_C).move_to(np.array([1.5,-1.5,1.87])).scale(0.5)
+ point_x_y_z2_2 = TexMobject("(0.5,-0.5,\\sqrt{4 - x^2 - y^2})").set_color(BLUE_C).move_to(np.array([1.5,-1.5,1.87])).scale(0.5)
+ point_x_y_z2_3 = TexMobject("(0.5,-0.5,\\sqrt{4 - 0.25 - 0.25})").set_color(BLUE_C).move_to(np.array([1.5,-1.5,1.87])).scale(0.5)
+ point_x_y_z2_4 = TexMobject("(0.5,-0.5,\\sqrt{3.5})").set_color(BLUE_C).move_to(np.array([1.5,-1.5,1.87])).scale(0.5)
+ point_x_y_z2_5 = TexMobject("(0.5,-0.5,1.87)").set_color(BLUE_C).move_to(np.array([1.5,-1.5,1.87])).scale(0.5)
+
+ point_x_y_z_2 = TexMobject("(0.5,-0.5,\\sqrt{r^2 - x^2 - y^2})").set_color(BLUE_C).move_to(np.array([1.5,-1.5,-1.87])).scale(0.5)
+ point_x_y_z_2_2 = TexMobject("(0.5,-0.5,\\sqrt{4 - x^2 - y^2})").set_color(BLUE_C).move_to(np.array([1.5,-1.5,-1.87])).scale(0.5)
+ point_x_y_z_2_3 = TexMobject("(0.5,-0.5,\\sqrt{4 - 0.25 - 0.25})").set_color(BLUE_C).move_to(np.array([1.5,-1.5,-1.87])).scale(0.5)
+ point_x_y_z_2_4 = TexMobject("(0.5,-0.5,\\sqrt{3.5})").set_color(BLUE_C).move_to(np.array([1.5,-1.5,-1.87])).scale(0.5)
+ point_x_y_z_2_5 = TexMobject("(0.5,-0.5,-1.87)").set_color(BLUE_C).move_to(np.array([1.5,-1.5,-1.87])).scale(0.5)
+
+
+ self.play(ShowCreation(dot_x_y2))
+ self.add_fixed_orientation_mobjects(point_x_y2)
+ self.play(ShowCreation(dot_x_y_z2), ShowCreation(dot_x_y_z_2), ShowCreation(line2))
+ self.add_fixed_orientation_mobjects(point_x_y_z2, point_x_y_z_2)
+ self.wait(0.5)
+ self.play(ReplacementTransform(point_x_y_z2,point_x_y_z2_2), ReplacementTransform(point_x_y_z_2,point_x_y_z_2_2))
+ self.add_fixed_orientation_mobjects(point_x_y_z2_2, point_x_y_z_2_2)
+
+ self.wait(0.5)
+ self.play(ReplacementTransform(point_x_y_z2_2,point_x_y_z2_3), ReplacementTransform(point_x_y_z_2_2,point_x_y_z_2_3))
+ self.add_fixed_orientation_mobjects(point_x_y_z2_3, point_x_y_z_2_3)
+ self.wait(0.5)
+ self.play(ReplacementTransform(point_x_y_z2_3,point_x_y_z2_4), ReplacementTransform(point_x_y_z_2_3,point_x_y_z_2_4))
+ self.add_fixed_orientation_mobjects(point_x_y_z2_4, point_x_y_z_2_4)
+ self.wait(0.5)
+ self.play(ReplacementTransform(point_x_y_z2_4,point_x_y_z2_5), ReplacementTransform(point_x_y_z_2_4,point_x_y_z_2_5))
+ self.add_fixed_orientation_mobjects(point_x_y_z2_5, point_x_y_z_2_5)
+
+ self.play(FadeOut(point_x_y1), FadeOut(point_x_y_z1_5), FadeOut(point_x_y_z_1_5), FadeOut(dot_x_y1), FadeOut(dot_x_y_z1), FadeOut(dot_x_y_z_1), FadeOut(line1))
+ self.play(FadeOut(point_x_y2), FadeOut(point_x_y_z2_5), FadeOut(point_x_y_z_2_5), FadeOut(dot_x_y2), FadeOut(dot_x_y_z2), FadeOut(dot_x_y_z_2), FadeOut(line2))
+
+
+
+
+ sphere_final = []
+
+ for u in range(0, 180, 15):
+ sphere_points1 = [np.array([2*np.sin(u*DEGREES)*np.cos(v*DEGREES), 2*np.sin(u*DEGREES)*np.sin(v*DEGREES), 2*np.cos(u*DEGREES)]) for v in range(0, 370, 10)]
+ sphere_dots1 = [Dot().scale(0.75).set_fill(RED_C).move_to(pts) for pts in sphere_points1]
+
+ sphere_points2 = [np.array([2*np.sin((u+5)*DEGREES)*np.cos(v*DEGREES), 2*np.sin((u+5)*DEGREES)*np.sin(v*DEGREES), 2*np.cos((u+5)*DEGREES)]) for v in range(0, 370, 10)]
+ sphere_dots2 = [Dot().scale(0.75).set_fill(RED_C).move_to(pts) for pts in sphere_points2]
+
+ sphere_points3 = [np.array([2*np.sin((u+10)*DEGREES)*np.cos(v*DEGREES), 2*np.sin((u+10)*DEGREES)*np.sin(v*DEGREES), 2*np.cos((u+10)*DEGREES)]) for v in range(0, 370, 10)]
+ sphere_dots3 = [Dot().scale(0.75).set_fill(RED_C).move_to(pts) for pts in sphere_points3]
+
+ sphere_final = sphere_final + sphere_dots1 + sphere_dots2 + sphere_dots3
+
+ sphere_dots = sphere_dots1 + sphere_dots2 + sphere_dots3
+
+ sphere_with_dots = VGroup(*sphere_dots)
+ self.play(ShowCreation(sphere_with_dots))
+
+ sphere_final_with_dots = VGroup(*sphere_final)
+
+
+ self.begin_ambient_camera_rotation(rate=0.5)
+ self.wait(3)
+ self.play(ReplacementTransform(sphere_final_with_dots, sphere))
+ self.wait(5)
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/file4_vectorvf_sine.py b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/file4_vectorvf_sine.py
new file mode 100644
index 0000000..06e225e
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/file4_vectorvf_sine.py
@@ -0,0 +1,91 @@
+from manimlib.imports import *
+
+class SineVectors(GraphScene):
+ CONFIG = {
+ "x_min": 0,
+ "x_max": 10,
+ "y_min": -1,
+ "y_max": 1,
+ "graph_origin": ORIGIN+4*LEFT,
+ #"x_labeled_nums": list(range(-5, 6)),
+ #"y_labeled_nums": list(range(0, 5)),
+ }
+ def construct(self):
+
+
+
+
+
+ XTD = self.x_axis_width/(self.x_max - self.x_min)
+ YTD = self.y_axis_height/(self.y_max - self.y_min)
+
+ self.setup_axes(animate = True)
+
+
+ sine1 = self.get_graph(lambda x : np.sin(x), x_min = 0, x_max = 1.575, color = GREEN)
+
+ point1 = Dot().shift(self.graph_origin+1*YTD*UP + 1.575*XTD*RIGHT)
+ point1_lab = TextMobject(r"$t = (\frac{\pi}{2})$")
+ point1_lab.scale(0.7)
+ point1_lab.next_to(point1, UP)
+
+ vector1 = Arrow(self.graph_origin, self.graph_origin+1*YTD*UP + 1.575*XTD*RIGHT, buff=0.1, color = RED)
+ vector1_lab = TextMobject(r"$r(\frac{\pi}{2})$", color = RED)
+ vector1_lab.move_to(self.graph_origin+1.5*XTD*RIGHT+ 0.5*YTD*UP)
+
+ self.play(GrowArrow(vector1),Write(vector1_lab))
+ self.play(ShowCreation(point1), Write(point1_lab))
+ self.play(ShowCreation(sine1))
+ self.wait(1)
+
+
+ sine2 = self.get_graph(lambda x : np.sin(x), x_min = 1.575, x_max = 3.15, color = GREEN)
+
+ point2 = Dot().shift(self.graph_origin+3.15*XTD*RIGHT)
+ point2_lab = TextMobject(r"$t = (\pi)$")
+ point2_lab.scale(0.7)
+ point2_lab.next_to(point2, UP+RIGHT)
+
+ vector2 = Arrow(self.graph_origin, self.graph_origin+3.15*XTD*RIGHT, buff=0.1, color = BLUE)
+ vector2_lab = TextMobject(r"$r(\pi)$", color = BLUE)
+ vector2_lab.move_to(self.graph_origin+1.5*XTD*RIGHT+ 0.15*YTD*UP)
+
+ self.play(GrowArrow(vector2),Write(vector2_lab))
+ self.play(ShowCreation(point2), Write(point2_lab))
+ self.play(ShowCreation(sine2))
+ self.wait(1)
+
+
+ sine3 = self.get_graph(lambda x : np.sin(x), x_min = 3.15, x_max = 4.725, color = GREEN)
+
+ point3 = Dot().shift(self.graph_origin+1*YTD*DOWN + 4.725*XTD*RIGHT)
+ point3_lab = TextMobject(r"$t = (\frac{3\pi}{2})$")
+ point3_lab.scale(0.7)
+ point3_lab.next_to(point3, DOWN)
+
+ vector3 = Arrow(self.graph_origin, self.graph_origin+1*YTD*DOWN + 4.725*XTD*RIGHT, buff=0.1, color = YELLOW_C)
+ vector3_lab = TextMobject(r"$r(\frac{3\pi}{2})$", color = YELLOW_C)
+ vector3_lab.move_to(self.graph_origin+2*XTD*RIGHT+ 0.7*YTD*DOWN)
+
+ self.play(GrowArrow(vector3),Write(vector3_lab))
+ self.play(ShowCreation(point3), Write(point3_lab))
+ self.play(ShowCreation(sine3))
+ self.wait(1)
+
+
+ sine4 = self.get_graph(lambda x : np.sin(x), x_min = 4.725, x_max = 6.3, color = GREEN)
+
+ point4 = Dot().shift(self.graph_origin+6.3*XTD*RIGHT)
+ point4_lab = TextMobject(r"$t = (2\pi)$")
+ point4_lab.scale(0.7)
+ point4_lab.next_to(point4, UP+RIGHT)
+
+ vector4 = Arrow(self.graph_origin, self.graph_origin+6.3*XTD*RIGHT, buff=0.1, color = PURPLE)
+ vector4_lab = TextMobject(r"$r(2\pi)$", color = PURPLE)
+ vector4_lab.move_to(self.graph_origin+4.5*XTD*RIGHT+ 0.15*YTD*DOWN)
+
+ self.play(GrowArrow(vector4),Write(vector4_lab))
+ self.play(ShowCreation(point4), Write(point4_lab))
+ self.play(ShowCreation(sine4))
+ self.wait(3)
+
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/file5_vectorvf_helix.py b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/file5_vectorvf_helix.py
new file mode 100644
index 0000000..fc151ac
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/file5_vectorvf_helix.py
@@ -0,0 +1,92 @@
+from manimlib.imports import *
+
+class Helix(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes() # creates a 3D Axis
+
+ helix1=ParametricFunction(
+ lambda u : np.array([
+ 1.5*np.cos(u),
+ 1.5*np.sin(u),
+ u/4
+ ]),color=PURPLE,t_min=-TAU,t_max=TAU,
+ )
+
+ helix2=ParametricFunction(
+ lambda u : np.array([
+ 2*np.cos(u),
+ 2*np.sin(u),
+ u/2
+ ]),color=GREEN_C,t_min=-TAU,t_max=TAU,
+ )
+
+ function = TexMobject("f(", "r", ",", "\\theta", ")", "=", "[", "r", "\\cos", "\\theta", ",", "r", "\\sin" ,"\\theta", ",", "h" ,"\\theta", "]" ).scale(0.6).to_corner(UL)
+ function.set_color_by_tex(r"\theta", BLUE_C)
+ function.set_color_by_tex(r"r", RED_C)
+ function.set_color_by_tex(r"\cos", GREEN_C)
+ function.set_color_by_tex(r"\sin", YELLOW_C)
+ function[0].set_color(ORANGE)
+ function[4].set_color(ORANGE)
+
+
+ self.add_fixed_in_frame_mobjects(function)
+
+ self.set_camera_orientation(phi=60*DEGREES, theta = 45*DEGREES)
+
+ self.add(axes)
+
+ axis = TextMobject(r"X",r"Y",r"Z")
+ axis[0].move_to(6*RIGHT)
+ axis[1].move_to(6*UP)
+ axis[2].move_to(np.array([0,0,3.7]))
+
+ self.add_fixed_orientation_mobjects(axis[2])
+ self.add_fixed_orientation_mobjects(axis[0])
+ self.add_fixed_orientation_mobjects(axis[1])
+
+
+ dot1 = Dot().rotate(PI/2).set_color(RED_C)
+ alpha1 = ValueTracker(0)
+ vector1 = self.get_vector(alpha1.get_value(),helix1)
+ dot1.add_updater(lambda m: m.move_to(vector1.get_end()))
+ self.play(
+ ShowCreation(helix1),
+ GrowFromCenter(dot1),
+ GrowArrow(vector1)
+ )
+ vector1.add_updater(
+ lambda m: m.become(
+ self.get_vector(alpha1.get_value()%1,helix1)
+ )
+ )
+ self.add(vector1,dot1)
+ self.play(alpha1.increment_value, 1, run_time=10, rate_func=linear)
+
+
+ self.play(FadeOut(vector1), FadeOut(dot1))
+ self.play(ReplacementTransform(helix1, helix2))
+
+
+ dot2 = Dot().rotate(PI/2).set_color(RED_C)
+ alpha2 = ValueTracker(0)
+ vector2 = self.get_vector(alpha2.get_value(),helix2)
+ dot2.add_updater(lambda m: m.move_to(vector2.get_end()))
+ self.play(
+ ShowCreation(helix2),
+ GrowFromCenter(dot2),
+ GrowArrow(vector2)
+ )
+ vector2.add_updater(
+ lambda m: m.become(
+ self.get_vector(alpha2.get_value()%1,helix2)
+ )
+ )
+ self.add(vector2,dot2)
+ self.play(alpha2.increment_value, 1, run_time=10, rate_func=linear)
+ self.wait()
+
+
+
+ def get_vector(self, proportion, curve):
+ vector = Line(np.array([0,0,0]), curve.point_from_proportion(proportion), color = YELLOW_C, buff=0)
+ return vector \ No newline at end of file
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/file6_derivative_vectorvf.py b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/file6_derivative_vectorvf.py
new file mode 100644
index 0000000..466e389
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/file6_derivative_vectorvf.py
@@ -0,0 +1,247 @@
+from manimlib.imports import *
+
+class Derivative(GraphScene):
+ CONFIG = {
+ "x_min": 0,
+ "x_max": 3,
+ "y_min": 0,
+ "y_max": 5,
+ "graph_origin": ORIGIN+6*LEFT+3*DOWN,
+ "x_axis_width": 6,
+ "x_labeled_nums": list(range(0, 4)),
+ "y_labeled_nums": list(range(0, 6)),
+ }
+ def construct(self):
+
+ XTD = self.x_axis_width/(self.x_max - self.x_min)
+ YTD = self.y_axis_height/(self.y_max - self.y_min)
+
+ self.setup_axes(animate = True)
+
+ graph = self.get_graph(lambda x : x*x, x_min = 0.5, x_max = 2, color = GREEN)
+
+ point1 = Dot().shift(self.graph_origin+0.25*YTD*UP + 0.5*XTD*RIGHT)
+ point1_lab = TextMobject(r"$t = a$")
+ point1_lab.scale(0.7)
+ point1_lab.next_to(point1, RIGHT)
+
+ point2 = Dot().shift(self.graph_origin+2*XTD*RIGHT+4*YTD*UP)
+ point2_lab = TextMobject(r"$t = b$")
+ point2_lab.scale(0.7)
+ point2_lab.next_to(point2, RIGHT)
+
+
+ vector1 = Arrow(self.graph_origin, self.graph_origin+1*YTD*UP + 1*XTD*RIGHT, buff=0.02, color = RED)
+ vector1_lab = TextMobject(r"$\vec r(t)$", color = RED)
+ vector1_lab.move_to(self.graph_origin+1.2*XTD*RIGHT+ 0.75*YTD*UP)
+ vector1_lab.scale(0.8)
+
+ vector2 = Arrow(self.graph_origin, self.graph_origin+2.25*YTD*UP + 1.5*XTD*RIGHT, buff=0.02, color = YELLOW_C)
+ vector2_lab = TextMobject(r"$\vec r(t + h)$", color = YELLOW_C)
+ vector2_lab.move_to(self.graph_origin+0.5*XTD*RIGHT+ 2*YTD*UP)
+ vector2_lab.scale(0.8)
+
+ vector3 = Arrow(self.graph_origin+1*YTD*UP + 1*XTD*RIGHT, self.graph_origin+2.25*YTD*UP + 1.5*XTD*RIGHT, buff=0.02, color = PINK)
+ vector3_lab = TextMobject(r"$\vec r(t + h) - \vec r(t)$", color = PINK)
+ vector3_lab.move_to(self.graph_origin+2*XTD*RIGHT+ 1.5*YTD*UP)
+ vector3_lab.scale(0.8)
+
+
+ self.play(ShowCreation(graph))
+ self.play(ShowCreation(point1), Write(point1_lab))
+ self.play(ShowCreation(point2), Write(point2_lab))
+
+ self.play(GrowArrow(vector1),Write(vector1_lab))
+ self.play(GrowArrow(vector2),Write(vector2_lab))
+ self.play(GrowArrow(vector3),Write(vector3_lab))
+ self.wait(1)
+
+ self.display_text()
+
+ self.play(ApplyMethod(vector3_lab.move_to,(self.graph_origin+2.3*XTD*RIGHT+ 2.2*YTD*UP)))
+
+ vector4 = Arrow(self.graph_origin+1*YTD*UP + 1*XTD*RIGHT, self.graph_origin+1*YTD*UP + 1.5*XTD*RIGHT, buff=0.02, color = PURPLE)
+ vector4_lab = TextMobject(r"$dx$", color = PURPLE)
+ vector4_lab.move_to(self.graph_origin+1.7*XTD*RIGHT+ 0.8*YTD*UP)
+ vector4_lab.scale(0.7)
+
+ vector5 = Arrow(self.graph_origin+1*YTD*UP + 1.5*XTD*RIGHT, self.graph_origin+2.25*YTD*UP + 1.5*XTD*RIGHT, buff=0.02, color = ORANGE)
+ vector5_lab = TextMobject(r"$dy$", color = ORANGE)
+ vector5_lab.move_to(self.graph_origin+1.7*XTD*RIGHT+ 1.4*YTD*UP)
+ vector5_lab.scale(0.7)
+
+ self.play(GrowArrow(vector4),Write(vector4_lab))
+ self.play(GrowArrow(vector5),Write(vector5_lab))
+ self.wait(2)
+
+
+
+ def display_text(self):
+ text1 = TextMobject(r"$\vec r(t)$",r"+", r"$\vec r(t + h) - \vec r(t)$")
+ text1[0].set_color(RED)
+ text1[2].set_color(PINK)
+ text1.scale(0.7)
+
+ text2 = TextMobject(r"$\vec r(t + h)$", color = YELLOW_C)
+ text2.scale(0.7)
+
+ text3 = TextMobject(r"$ \vec r(t + h) - \vec r(t)$", color = PINK)
+ text3.scale(0.7)
+
+ text4 = TextMobject(r"[", r"$x(t+h)$", r"$\vec i$", r"+", r"$y(t+h)$", r"$\vec j$", r"$] - [$", r"$x(t)$", r"$\vec i$", r"+", r"y(t)", r"$\vec j$", r"]")
+ text4.set_color_by_tex(r"\vec i", BLUE)
+ text4.set_color_by_tex(r"\vec j", GREEN)
+ text4[1].set_color(YELLOW_C)
+ text4[4].set_color(YELLOW_C)
+ text4[-6].set_color(RED)
+ text4[-3].set_color(RED)
+ text4.scale(0.7)
+
+ text5 = TextMobject(r"$[x(t+h) - x(t)]$", r"$\vec i$", r"+", r"$[y(t+h) + y(t)]$", r"$\vec j$")
+ text5.set_color_by_tex(r"\vec i", BLUE)
+ text5.set_color_by_tex(r"\vec j", GREEN)
+ text5[0].set_color(PURPLE)
+ text5[3].set_color(ORANGE)
+ text5.scale(0.7)
+
+ text6 = TextMobject(r"$\frac{[\vec r(t + h) - \vec r(t)]}{h}$", r"=", r"$\frac{[x(t+h) - x(t)]}{h}$", r"$\vec i$", r"+", r"$\frac{[y(t+h) + y(t)]}{h}$", r"$\vec j$")
+ text6.set_color_by_tex(r"\vec i", BLUE)
+ text6.set_color_by_tex(r"\vec j", GREEN)
+ text6[0].set_color(PINK)
+ text6[2].set_color(PURPLE)
+ text6[-2].set_color(ORANGE)
+ text6.scale(0.8)
+
+ text7 = TextMobject(r"$\lim_{h \rightarrow 0}$", r"$\frac{[\vec r(t + h) - \vec r(t)]}{h}$", r"=", r"$\lim_{h \rightarrow 0}$", r"$\frac{[x(t+h) - x(t)]}{h}$", r"$\vec i$", r"+", r"$\lim_{h \rightarrow 0}$", r"$\frac{[y(t+h) + y(t)]}{h}$", r"$\vec j$")
+ text7.set_color_by_tex(r"\vec i", BLUE)
+ text7.set_color_by_tex(r"\vec j", GREEN)
+ text7[1].set_color(PINK)
+ text7[4].set_color(PURPLE)
+ text7[-2].set_color(ORANGE)
+ text7.scale(0.6)
+
+ text8 = TextMobject(r"$\vec r'(t)$", r"=",r"$\vec x'(t)$", r"$\vec i$", r"+", r"$\vec y'(t)$", r"$\vec j$")
+ text8.set_color_by_tex(r"\vec i", BLUE)
+ text8.set_color_by_tex(r"\vec j", GREEN)
+ text8[0].set_color(PINK)
+ text8[2].set_color(PURPLE)
+ text8[5].set_color(ORANGE)
+ text8.scale(0.7)
+
+ text9 = TextMobject(r"$\frac{d \vec r}{dt}$", r"=", r"$\frac{d \vec x}{dt}$", r"$\vec i$", r"+", r"$\frac{d \vec y}{dt}$", r"$\vec j$")
+ text9.set_color_by_tex(r"\vec i", BLUE)
+ text9.set_color_by_tex(r"\vec j", GREEN)
+ text9[0].set_color(PINK)
+ text9[2].set_color(PURPLE)
+ text9[5].set_color(ORANGE)
+ text9.scale(0.7)
+
+
+ text10 = TextMobject(r"$d \vec r$", r"=", r"$\frac{d \vec x}{dt}dt$", r"$\vec i$", r"+", r"$\frac{d \vec y}{dt}dt$", r"$\vec j$")
+ text10.set_color_by_tex(r"\vec i", BLUE)
+ text10.set_color_by_tex(r"\vec j", GREEN)
+ text10[0].set_color(PINK)
+ text10[2].set_color(PURPLE)
+ text10[5].set_color(ORANGE)
+ text10.scale(0.7)
+
+ text11 = TextMobject(r"$d \vec r$", r"=", r"$x'(t)dt$", r"$\vec i$", r"+", r"$y'(t)dt$", r"$\vec j$")
+ text11.set_color_by_tex(r"\vec i", BLUE)
+ text11.set_color_by_tex(r"\vec j", GREEN)
+ text11[0].set_color(PINK)
+ text11[2].set_color(PURPLE)
+ text11[5].set_color(ORANGE)
+ text11.scale(0.7)
+
+ text12 = TextMobject(r"$d \vec r$", r"=", r"$dx$", r"$\vec i$", r"+", r"$dy$", r"$\vec j$")
+ text12.set_color_by_tex(r"\vec i", BLUE)
+ text12.set_color_by_tex(r"\vec j", GREEN)
+ text12[0].set_color(PINK)
+ text12[2].set_color(PURPLE)
+ text12[5].set_color(ORANGE)
+ text12.scale(0.7)
+
+
+ text1.move_to(1*UP+2.7*RIGHT)
+ text2.move_to(1*UP+2.7*RIGHT)
+ text3.move_to(1*UP+2.7*RIGHT)
+ text4.move_to(1*UP+2.7*RIGHT)
+ text5.move_to(1*UP+2.7*RIGHT)
+ text6.move_to(1*UP+2.7*RIGHT)
+ text7.move_to(1*UP+2.5*RIGHT)
+ text8.move_to(1*UP+2.7*RIGHT)
+ text9.move_to(1*UP+2.7*RIGHT)
+ text10.move_to(1*UP+2.7*RIGHT)
+ text11.move_to(1*UP+2.7*RIGHT)
+ text12.move_to(1*UP+2.7*RIGHT)
+
+ brace1 = Brace(text7[0:2], DOWN, buff = SMALL_BUFF)
+ brace2 = Brace(text7[3:6], UP, buff = SMALL_BUFF)
+ brace3 = Brace(text7[7:], DOWN, buff = SMALL_BUFF)
+ t1 = brace1.get_text(r"$\vec r'(t)$")
+ t1.set_color(PINK)
+
+ t2 = brace2.get_text(r"$\vec x'(t)$")
+ t2.set_color(PURPLE)
+
+ t3 = brace3.get_text(r"$\vec y'(t)$")
+ t3.set_color(ORANGE)
+
+
+ self.play(Write(text1))
+ self.play(Transform(text1, text2))
+ self.wait(1)
+
+ self.play(Transform(text1, text3))
+ self.wait(1)
+
+ self.play(Transform(text1, text4))
+ self.wait(1)
+
+ self.play(Transform(text1, text5))
+ self.wait(1)
+
+ self.play(Transform(text1, text6))
+ self.wait(1)
+
+ self.play(Transform(text1, text7))
+ self.wait(1)
+
+ self.play(
+ GrowFromCenter(brace1),
+ FadeIn(t1),
+ )
+ self.wait()
+ self.play(
+ ReplacementTransform(brace1.copy(),brace2),
+ ReplacementTransform(t1.copy(),t2)
+ )
+ self.wait()
+ self.play(
+ ReplacementTransform(brace2.copy(),brace3),
+ ReplacementTransform(t2.copy(),t3)
+ )
+ self.wait()
+
+ self.play(FadeOut(brace1), FadeOut(t1), FadeOut(brace2), FadeOut(t2), FadeOut(brace3), FadeOut(t3),)
+ self.wait()
+
+ self.play(Transform(text1, text8))
+ self.wait(1)
+
+ self.play(Transform(text1, text9))
+ self.wait(1)
+
+ self.play(Transform(text1, text10))
+ self.wait(1)
+
+ self.play(Transform(text1, text11))
+ self.wait(1)
+
+ self.play(Transform(text1, text12))
+ self.wait(1)
+
+
+
+
+
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/gifs/file1_multivar_func_examples.gif b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/gifs/file1_multivar_func_examples.gif
new file mode 100644
index 0000000..43c3a42
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/gifs/file1_multivar_func_examples.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/gifs/file2_multivariable_func_respresentation.gif b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/gifs/file2_multivariable_func_respresentation.gif
new file mode 100644
index 0000000..8c4506c
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/gifs/file2_multivariable_func_respresentation.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/gifs/file3_sphere.gif b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/gifs/file3_sphere.gif
new file mode 100644
index 0000000..3e35ec8
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/gifs/file3_sphere.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/gifs/file4_vectorvf_sine.gif b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/gifs/file4_vectorvf_sine.gif
new file mode 100644
index 0000000..215459e
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/gifs/file4_vectorvf_sine.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/gifs/file5_vectorvf_helix.gif b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/gifs/file5_vectorvf_helix.gif
new file mode 100644
index 0000000..c3d37f6
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/gifs/file5_vectorvf_helix.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/gifs/file6_derivative_vectorvf.gif b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/gifs/file6_derivative_vectorvf.gif
new file mode 100644
index 0000000..9ea94e4
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-functions/gifs/file6_derivative_vectorvf.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/Limits_and_Continuity_of_Multivariable_Function_Quiz.pdf b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/Limits_and_Continuity_of_Multivariable_Function_Quiz.pdf
new file mode 100644
index 0000000..99918e5
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/Limits_and_Continuity_of_Multivariable_Function_Quiz.pdf
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/README.md b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/README.md
new file mode 100644
index 0000000..c01ddc5
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/README.md
@@ -0,0 +1,14 @@
+**file1_epsilon_delta_defn**
+![file1_epsilon_delta_defn](https://github.com/nishanpoojary/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/gifs/file1_epsilon_delta_defn.gif)
+
+**file2_limit_approach_point**
+![file2_limit_approach_point](https://github.com/nishanpoojary/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/gifs/file2_limit_approach_point.gif)
+
+**file3_limit_approach_point_3d**
+![file3_limit_approach_point_3d](https://github.com/nishanpoojary/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/gifs/file3_limit_approach_point_3d.gif)
+
+**file4_limit_different_point**
+![file4_limit_different_point](https://github.com/nishanpoojary/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/gifs/file4_limit_different_point.gif)
+
+**file5_continuity_func**
+![file5_continuity_func](https://github.com/nishanpoojary/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/gifs/file5_continuity_func.gif)
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/file1_epsilon_delta_defn.py b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/file1_epsilon_delta_defn.py
new file mode 100644
index 0000000..803c122
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/file1_epsilon_delta_defn.py
@@ -0,0 +1,179 @@
+from manimlib.imports import *
+
+class EpsilonDelta(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes() # creates a 3D Axis
+
+
+ sphere = ParametricSurface(
+ lambda u, v: np.array([
+ 3*np.sin(u)*np.cos(v),
+ 3*np.sin(u)*np.sin(v),
+ 3*np.cos(u)
+ ]),u_min=0,u_max=PI/4,v_min=PI/2,v_max=PI,checkerboard_colors=[RED_D, RED_E],
+ resolution=(15, 32)).scale(1)
+
+
+ cylinder_z = ParametricSurface(
+ lambda u, v: np.array([
+ 0.25*np.cos(TAU * v),
+ 1.8* (1 - u),
+ 0.25*np.sin(TAU * v)
+
+ ]),
+ checkerboard_colors=[YELLOW_C, YELLOW_E], resolution=(6, 32)).fade(0.2).rotate(PI/4).move_to(np.array([-0.65,0.65,2.54]))
+
+
+ cylinder_x = ParametricSurface(
+ lambda u, v: np.array([
+ 0.3*np.cos(TAU * v)-1,
+ 0.3*np.sin(TAU * v)+1,
+ 2.6*(1 - u)
+ ]),
+ checkerboard_colors=[BLUE_C, BLUE_E], resolution=(6, 32)).fade(0.2)
+
+
+ delta_circle = Circle(radius= 0.3, color = BLACK).shift(1*LEFT+1*UP).set_fill(GREEN_E, opacity = 0.5)
+
+ epsilon_circle = [np.array([0.25*np.cos(i*DEGREES),0,0.25*np.sin(i*DEGREES)]) for i in range(361)]
+
+ epsilon_circle_polygon = Polygon(*epsilon_circle, color = RED_E, fill_color = RED_E, fill_opacity = 0.5).rotate(PI/4).move_to(np.array([0,0,2.54]))
+
+
+ dot_circle = Dot().move_to(np.array([-1,1,0])).set_fill("#000080")
+
+ dot_surface = Dot().rotate(-PI/4).scale(1.5).move_to(np.array([-1.2,1.2,2.7])).set_fill("#000080")
+
+ dot_L_epsilon1 = Polygon(*[np.array([0.05*np.cos(i*DEGREES),0,0.05*np.sin(i*DEGREES)]) for i in range(361)], color = "#000080", fill_color = "#000080", fill_opacity = 1).rotate(PI/4).move_to(np.array([0,0,2.3]))
+
+ dot_L_epsilon2 = Polygon(*[np.array([0.05*np.cos(i*DEGREES),0,0.05*np.sin(i*DEGREES)]) for i in range(361)], color = "#000080", fill_color = "#000080", fill_opacity = 1).rotate(PI/4).move_to(np.array([0,0,2.8]))
+
+ dot_L = Polygon(*[np.array([0.05*np.cos(i*DEGREES),0,0.05*np.sin(i*DEGREES)]) for i in range(361)], color = "#006400", fill_color = "#006400", fill_opacity = 1).rotate(PI/4).move_to(np.array([0,0,2.54]))
+
+
+
+ self.add(axes)
+
+ axis = TextMobject(r"X",r"Y",r"Z")
+ axis[0].move_to(6*RIGHT)
+ axis[1].move_to(6*UP)
+ axis[2].move_to(np.array([0,0,3.7]))
+
+ self.add_fixed_orientation_mobjects(axis[2])
+ self.add_fixed_orientation_mobjects(axis[0])
+ self.add_fixed_orientation_mobjects(axis[1])
+
+ self.set_camera_orientation(phi=75*DEGREES,theta=135*DEGREES)
+ #self.set_camera_orientation(phi=80*DEGREES,theta=45*DEGREES)
+
+
+ self.play(ShowCreation(sphere),ShowCreation(delta_circle), ShowCreation(dot_circle))
+
+ temp_circle_center = TextMobject(r"$(a,b,0)$").scale(0.6).set_color(BLUE_C).move_to(1.7*LEFT+1.1*UP)
+ self.add_fixed_orientation_mobjects(temp_circle_center)
+ self.wait()
+
+ delta_lab = TextMobject(r"$\delta$", r"$-$", "disk").scale(0.5).move_to(0.6*LEFT+1.7*UP)
+ delta_lab[0].set_color(PINK).scale(1.3)
+ delta_lab[1].set_color(ORANGE)
+ delta_lab[2].set_color(GREEN_E)
+
+ self.add_fixed_orientation_mobjects(delta_lab)
+
+ self.play(ShowCreation(dot_surface))
+
+ temp_curve_circle_center = TextMobject(r"$(a,b,L)$").scale(0.6).set_color("#006400").move_to(np.array([-2,1,2.7]))
+ self.add_fixed_orientation_mobjects(temp_curve_circle_center)
+
+
+ self.wait()
+ self.play(ShowCreation(cylinder_x), FadeOut(dot_surface))
+ self.wait()
+
+ self.move_camera(phi=0* DEGREES,theta=135*DEGREES)
+ self.wait()
+
+ self.move_camera(phi=80* DEGREES,theta=225*DEGREES)
+ self.wait()
+
+ self.play(FadeOut(delta_lab), ShowCreation(cylinder_z))
+ self.wait()
+
+ self.play(FadeOut(temp_circle_center), FadeOut(temp_curve_circle_center),ShowCreation(epsilon_circle_polygon))
+
+ self.move_camera(phi=80* DEGREES,theta=325*DEGREES)
+
+ dot_L_epsilon1_lab = TextMobject(r"$L$", r"$-$", r"$\epsilon$").scale(0.6).move_to(np.array([-0.4,-0.4,2.3]))
+ dot_L_epsilon1_lab[0].set_color("#D4108A")
+ dot_L_epsilon1_lab[1].set_color("#006400")
+ dot_L_epsilon1_lab[2].set_color("#4DC8A1").scale(1.5)
+
+ dot_L_epsilon2_lab = TextMobject(r"$L$", r"$+$", r"$\epsilon$").scale(0.6).move_to(np.array([-0.4,-0.4,2.8]))
+ dot_L_epsilon2_lab[0].set_color("#D4108A")
+ dot_L_epsilon2_lab[1].set_color("#006400")
+ dot_L_epsilon2_lab[2].set_color("#4DC8A1").scale(1.5)
+
+ dot_L_lab = TextMobject(r"$L$").scale(0.6).set_color("#D4108A").move_to(np.array([-0.4,-0.4,2.54]))
+
+
+ self.play(ShowCreation(dot_L_epsilon1), ShowCreation(dot_L), ShowCreation(dot_L_epsilon2))
+ self.add_fixed_orientation_mobjects(dot_L_epsilon1_lab, dot_L_epsilon2_lab, dot_L_lab)
+ self.wait(4)
+
+ self.move_camera(phi=80* DEGREES,theta=45*DEGREES)
+ self.wait(2)
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ '''
+
+
+
+
+
+
+
+
+
+
+
+ delta_lab = TextMobject(r"$\delta - disk$")
+ delta_lab.scale(0.5)
+ delta_lab.set_color(PINK)
+
+ self.play(ShowCreation(circle_center))
+ self.add_fixed_in_frame_mobjects(temp_circle_center)
+ temp_circle_center.move_to(1.5*RIGHT)
+ self.play(Write(temp_circle_center))
+
+ self.play(ShowCreation(curve_circle_center))
+ self.add_fixed_in_frame_mobjects(temp_curve_circle_center)
+ temp_curve_circle_center.move_to(1.9*UP+1*RIGHT)
+ self.play(Write(temp_curve_circle_center))
+
+
+ self.add_fixed_in_frame_mobjects(delta_lab)
+ delta_lab.move_to(0.4*DOWN+1.7*RIGHT)
+ self.play(Write(delta_lab))
+
+
+
+
+
+ self.begin_ambient_camera_rotation(rate=0.2)
+
+ self.play(ShowCreation(circle), ShowCreation(line1), ShowCreation(line2))
+ self.play(ShowCreation(line3), ShowCreation(line4))
+ self.wait(8)
+ ''' \ No newline at end of file
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/file2_limit_approach_point.py b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/file2_limit_approach_point.py
new file mode 100644
index 0000000..57d1d45
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/file2_limit_approach_point.py
@@ -0,0 +1,66 @@
+from manimlib.imports import *
+
+class Limit(GraphScene):
+ CONFIG = {
+ "x_min": 0,
+ "x_max": 4,
+ "y_min": 0,
+ "y_max": 4,
+ "graph_origin": ORIGIN + 3* DOWN+4*LEFT,
+ "x_labeled_nums": list(range(0, 4)),
+ "y_labeled_nums": list(range(0, 5)),
+ }
+ def construct(self):
+ topic = TextMobject("Different paths of approach to limit point")
+ topic.scale(1.5)
+ topic.set_color_by_gradient(RED, ORANGE, YELLOW, GREEN, BLUE, PURPLE)
+ self.play(Write(topic))
+ self.wait(1)
+ self.play(FadeOut(topic))
+
+
+
+ XTD = self.x_axis_width/(self.x_max- self.x_min)
+ YTD = self.y_axis_height/(self.y_max- self.y_min)
+
+ self.setup_axes(animate = True)
+
+ y_x = self.get_graph(lambda x : x, x_min = -1, x_max = 4)
+ y_x_lab = self.get_graph_label(y_x, label = r"y = x")
+
+ y_xsquare = self.get_graph(lambda x : x*x, x_min = -1, x_max = 4)
+ y_xsquare_lab = self.get_graph_label(y_xsquare, label = r"y = x^2")
+
+ y_1 = self.get_graph(lambda x : 1, x_min = -1, x_max = 4)
+ y_1_lab = self.get_graph_label(y_1, label = r"y = 1")
+
+ y_2minusx = self.get_graph(lambda x : 2 - x, x_min = -1, x_max = 4, color = RED)
+ y_2minusx_lab = self.get_graph_label(y_2minusx, label = r"y = 2 - x")
+
+ limit_point = Dot().shift(self.graph_origin+1*XTD*RIGHT+1*YTD*UP)
+ limit_point_lab = TextMobject(r"(1,1)")
+ limit_point_lab.next_to(limit_point, DOWN)
+
+ self.play(ShowCreation(limit_point))
+ self.play(Write(limit_point_lab))
+ self.wait(1)
+
+ self.play(ShowCreation(y_x))
+ self.play(Write(y_x_lab))
+ self.wait(1)
+
+ self.play(ShowCreation(y_xsquare))
+ self.play(Write(y_xsquare_lab))
+ self.wait(1)
+
+ self.play(ShowCreation(y_1))
+ self.play(Write(y_1_lab))
+ self.wait(1)
+
+ self.play(ShowCreation(y_2minusx))
+ self.play(Write(y_2minusx_lab))
+ self.wait(1)
+
+
+
+ \ No newline at end of file
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/file3_limit_approach_point_3d.py b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/file3_limit_approach_point_3d.py
new file mode 100644
index 0000000..f1007a4
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/file3_limit_approach_point_3d.py
@@ -0,0 +1,152 @@
+from manimlib.imports import *
+
+class Limit(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes()
+
+ text3d = TextMobject(r"$f(x,y) = \frac{x - y}{x - 1}$")
+ self.add_fixed_in_frame_mobjects(text3d)
+
+ text3d.to_corner(UL)
+
+ text3d.set_color_by_gradient(RED, ORANGE, YELLOW, GREEN, BLUE, PURPLE)
+
+ self.play(Write(text3d))
+ self.wait(1)
+
+ limit_func = ParametricSurface(
+ lambda u, v: np.array([
+ 3*np.sin(u)*np.cos(v),
+ 3*np.sin(u)*np.sin(v),
+ (3*np.sin(u)*np.cos(v) - 3*np.sin(u)*np.sin(v))/2*(3*np.sin(u)*np.cos(v) - 1)
+ ]),u_min=0,u_max=PI,v_min=0,v_max=2*PI, color = BLUE_C, fill_color = BLUE_C, fill_opacity = 0.1,
+ resolution=(15, 32)).scale(1)
+
+ limit_y_x =ParametricFunction(
+ lambda u : np.array([
+ u,
+ u,
+ 0
+ ]),color=GREEN_D,t_min=-3,t_max=3,
+ )
+
+ limit_y_1 =ParametricFunction(
+ lambda u : np.array([
+ u,
+ 1,
+ 1/2
+ ]),color=BLUE_D,t_min=-3,t_max=3,
+ )
+
+ limit_y_x_2 =ParametricFunction(
+ lambda u : np.array([
+ u,
+ u*u,
+ (u - u*u)/2*(u - 1)
+ ]),color=RED_D,t_min=-3,t_max=3,
+ )
+
+ limit_y_2_x =ParametricFunction(
+ lambda u : np.array([
+ u,
+ 2 - u,
+ 1
+ ]),color=YELLOW_D,t_min=-3,t_max=3,
+ )
+
+ plane_y_x = Polygon(np.array([-3,-3,-3]),np.array([3,3,-3]),np.array([3,3,3]),np.array([-3,-3,3]),np.array([-3,-3,-3]), color = GREEN_C, fill_color = GREEN_C, fill_opacity = 0.1)
+ plane_y_x_text = TextMobject(r"$y = x$", color = GREEN_C).move_to(np.array([5,0,3]))
+
+ plane_y_1 = Polygon(np.array([-3,1,-3]),np.array([3,1,-3]),np.array([3,1,3]),np.array([-3,1,3]),np.array([-3,1,-3]), color = BLUE_C, fill_color = BLUE_C, fill_opacity = 0.1)
+ plane_y_1_text = TextMobject(r"$y = 1$", color = BLUE_C).move_to(np.array([5,0,2.5]))
+
+
+ #Creating plane y = x^2
+ ######
+ y_x_2 = []
+ y_x_2.append(np.array([2, 4, -3]))
+ y_x_2.append(np.array([2, 4, 3]))
+ y_x_2_1 = [np.array([i, i*i, 3]) for i in np.arange(1.9,-2.1, -0.1)]
+
+ y_x_2 = y_x_2 + y_x_2_1
+
+ y_x_2.append(np.array([-2, 4, 3]))
+ y_x_2.append(np.array([-2, 4, -3]))
+
+ y_x_2_2 = [np.array([i, i*i, -3]) for i in np.arange(-2,2.1, 0.1)]
+
+ y_x_2 = y_x_2 + y_x_2_2
+ #y_x_2.append(np.array([-3, 9, 0]))
+
+ plane_y_x_2 = Polygon(*y_x_2, color = RED_C, fill_color = RED_C, fill_opacity = 0.1)
+ plane_y_x_2_text = TextMobject(r"$y = x^2$", color = RED_C).move_to(np.array([5,0,2]))
+
+ ######
+
+ plane_y_2_x = Polygon(np.array([-3,5,-3]),np.array([3,-1,-3]),np.array([3,-1,3]),np.array([-3,5,3]),np.array([-3,5,-3]), color = YELLOW_C, fill_color = YELLOW_C, fill_opacity = 0.1)
+ plane_y_2_x_text = TextMobject(r"$y = 2 - x$", color = YELLOW_C).move_to(np.array([5,0,1.5]))
+
+ line_1_1 = Line(np.array([1,1,-3]), np.array([1,1,3]), color = PINK)
+
+ point = Polygon(*[np.array([0.05*np.cos(i*DEGREES),0,0.05*np.sin(i*DEGREES)]) for i in range(361)], color = "#000080", fill_color = "#000080", fill_opacity = 1).move_to(np.array([1,1,0]))
+ point_text = TextMobject(r"$(1,1,0)$", color = WHITE).scale(0.7).move_to(np.array([1.8,1,0]))
+
+
+
+
+ self.set_camera_orientation(phi=70 * DEGREES, theta = -95*DEGREES)
+
+
+ self.add(axes)
+
+ axis = TextMobject(r"X",r"Y",r"Z")
+ axis[0].move_to(6*RIGHT)
+ axis[1].move_to(6*UP)
+ axis[2].move_to(3.7*UP)
+
+ self.add_fixed_in_frame_mobjects(axis[2])
+ self.add_fixed_orientation_mobjects(axis[0])
+ self.add_fixed_orientation_mobjects(axis[1])
+
+ self.play(ShowCreation(limit_func))
+ self.wait(2)
+
+ self.play(ShowCreation(plane_y_x))
+ self.add_fixed_orientation_mobjects(plane_y_x_text)
+ self.play(ShowCreation(limit_y_x))
+ self.wait()
+
+ self.play(ShowCreation(plane_y_1))
+ self.add_fixed_orientation_mobjects(plane_y_1_text)
+ self.play(ShowCreation(limit_y_1))
+ self.wait()
+
+ self.play(ShowCreation(plane_y_x_2))
+ self.add_fixed_orientation_mobjects(plane_y_x_2_text)
+ self.play(ShowCreation(limit_y_x_2))
+ self.wait()
+
+ self.play(ShowCreation(plane_y_2_x))
+ self.add_fixed_orientation_mobjects(plane_y_2_x_text)
+ self.play(ShowCreation(limit_y_2_x))
+ self.wait()
+
+ self.play(ShowCreation(line_1_1))
+ self.wait()
+
+ self.play(ShowCreation(point))
+ self.add_fixed_orientation_mobjects(point_text)
+ self.wait()
+
+ self.play(FadeOut(plane_y_x_text), FadeOut(plane_y_1_text), FadeOut(plane_y_x_2_text), FadeOut(plane_y_2_x_text))
+
+ self.move_camera(phi=0* DEGREES,theta=-95*DEGREES)
+ self.wait(2)
+ self.play(FadeOut(plane_y_x), FadeOut(plane_y_1), FadeOut(plane_y_x_2), FadeOut(plane_y_2_x))
+ self.wait(3)
+
+ self.move_camera(phi=75* DEGREES,theta=-95*DEGREES)
+ self.wait(3)
+
+
+ \ No newline at end of file
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/file4_limit_different_point.py b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/file4_limit_different_point.py
new file mode 100644
index 0000000..0a43def
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/file4_limit_different_point.py
@@ -0,0 +1,115 @@
+from manimlib.imports import *
+
+class DifferentPoint(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes()
+
+ text3d = TextMobject(r"$f(x,y) = \frac{x^2 - y^2}{x^2 + y^2}$")
+ self.add_fixed_in_frame_mobjects(text3d)
+
+ text3d.to_corner(UL)
+
+ text3d.set_color_by_gradient(RED, ORANGE, YELLOW, GREEN, BLUE, PURPLE)
+
+ self.play(Write(text3d))
+ self.wait(1)
+
+ limit_func = ParametricSurface(
+ lambda u, v: np.array([
+ 3*np.sin(u)*np.cos(v),
+ 3*np.sin(u)*np.sin(v),
+ (np.cos(v)*np.cos(v) - np.sin(v)*np.sin(v))
+ ]),u_min=0,u_max=PI,v_min=0,v_max=2*PI,checkerboard_colors=[YELLOW_C, YELLOW_E],
+ resolution=(15, 32)).scale(1)
+
+ limit_func_copy1 = limit_func.copy()
+ limit_func_copy2 = limit_func.copy()
+
+ limit_func_x = ParametricSurface(
+ lambda u, v: np.array([
+ 3*np.sin(u)*np.cos(v),
+ 3*np.sin(u)*np.sin(v),
+ (np.cos(v)*np.cos(v) - np.sin(v)*np.sin(v))
+ ]),u_min=0,u_max=PI,v_min=PI,v_max=2*PI,checkerboard_colors=[YELLOW_C, YELLOW_E],
+ resolution=(15, 32)).scale(1)
+
+ limit_func_y = ParametricSurface(
+ lambda u, v: np.array([
+ 3*np.sin(u)*np.cos(v),
+ 3*np.sin(u)*np.sin(v),
+ (np.cos(v)*np.cos(v) - np.sin(v)*np.sin(v))
+ ]),u_min=0,u_max=PI,v_min=PI/2,v_max=3*PI/2,checkerboard_colors=[YELLOW_C, YELLOW_E],
+ resolution=(15, 32)).scale(1)
+
+ limit_x =ParametricFunction(
+ lambda u : np.array([
+ u,
+ 0,
+ 1
+ ]),color="#006400",t_min=-3,t_max=3,
+ )
+
+ limit_y =ParametricFunction(
+ lambda u : np.array([
+ 0,
+ u,
+ -1
+ ]),color="#000080",t_min=-3,t_max=3,
+ )
+
+ plane_x = Polygon(np.array([-3,0,-2]),np.array([3,0,-2]),np.array([3,0,2]),np.array([-3,0,2]),np.array([-3,0,-2]), color = GREEN, fill_color = GREEN, fill_opacity = 0.2)
+ plane_x_text = TextMobject(r"$y = 0$", color = GREEN_C).move_to(1.7*UP + 3.8*RIGHT)
+
+ plane_y = Polygon(np.array([0,-3,-2]),np.array([0,3,-2]),np.array([0,3,2]),np.array([0,-3,2]),np.array([0,-3,-2]), color = BLUE, fill_color = BLUE, fill_opacity = 0.2)
+ plane_y_text = TextMobject(r"$x = 0$", color = BLUE_C).move_to(1.7*UP + 3.8*RIGHT)
+
+ origin_x = Polygon(*[np.array([0.05*np.cos(i*DEGREES),0,0.05*np.sin(i*DEGREES)]) for i in range(361)], color = "#000080", fill_color = "#000080", fill_opacity = 1).move_to(np.array([0,0,0]))
+ origin_x_text = TextMobject(r"$(0,0,0)$", color = RED_C).scale(0.7).move_to(np.array([-0.6,0,-0.5]))
+
+ origin_y = Polygon(*[np.array([0,0.05*np.cos(i*DEGREES),0.05*np.sin(i*DEGREES)]) for i in range(361)], color = "#000080", fill_color = "#000080", fill_opacity = 1).move_to(np.array([0,0,0]))
+ origin_y_text = TextMobject(r"$(0,0,0)$", color = RED_C).scale(0.7).move_to(np.array([0,-0.6,-0.5]))
+
+ self.set_camera_orientation(phi=80 * DEGREES, theta = 0*DEGREES)
+
+
+ self.add(axes)
+
+ axis = TextMobject(r"X",r"Y",r"Z")
+ axis[0].move_to(6*RIGHT)
+ axis[1].move_to(6*UP)
+ axis[2].move_to(3.7*UP)
+
+ self.add_fixed_in_frame_mobjects(axis[2])
+ self.add_fixed_orientation_mobjects(axis[0])
+ self.add_fixed_orientation_mobjects(axis[1])
+
+ self.play(ShowCreation(limit_func))
+
+ self.move_camera(phi=80* DEGREES,theta=105*DEGREES)
+
+ self.play(ShowCreation(plane_x))
+ self.add_fixed_in_frame_mobjects(plane_x_text)
+ self.wait()
+ self.play(ReplacementTransform(limit_func, limit_func_x))
+ self.play(FadeOut(plane_x), FadeOut(plane_x_text), ShowCreation(origin_x))
+ self.add_fixed_orientation_mobjects(origin_x_text)
+ self.play(ShowCreation(limit_x))
+
+ self.move_camera(phi=80* DEGREES,theta=15*DEGREES)
+ self.wait(3)
+
+ self.play(FadeOut(origin_x), FadeOut(origin_x_text), FadeOut(limit_x), ReplacementTransform(limit_func_x, limit_func_copy1))
+ self.play(ShowCreation(plane_y))
+ self.add_fixed_in_frame_mobjects(plane_y_text)
+ self.wait()
+ self.play(ReplacementTransform(limit_func_copy1, limit_func_y))
+ self.play(FadeOut(plane_y), FadeOut(plane_y_text), ShowCreation(origin_y))
+ self.add_fixed_orientation_mobjects(origin_y_text)
+ self.play(ShowCreation(limit_y))
+
+ self.move_camera(phi=80* DEGREES,theta=75*DEGREES)
+ self.wait(3)
+
+ self.play(FadeOut(origin_y), FadeOut(origin_y_text), FadeOut(limit_y), ReplacementTransform(limit_func_y, limit_func_copy2))
+ self.wait(2)
+ \ No newline at end of file
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/file5_continuity_func.py b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/file5_continuity_func.py
new file mode 100644
index 0000000..99159a4
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/file5_continuity_func.py
@@ -0,0 +1,115 @@
+from manimlib.imports import *
+
+class Continuity(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes()
+
+ text3d = TextMobject(r"$f(x,y) = \frac{3x^2y}{x^2 + y^2}$")
+ self.add_fixed_in_frame_mobjects(text3d)
+
+ text3d.to_corner(UL)
+
+ text3d.set_color_by_gradient(RED, ORANGE, YELLOW, GREEN, BLUE, PURPLE)
+
+ self.play(Write(text3d))
+ self.wait(1)
+
+
+ continuity_func = ParametricSurface(
+ lambda u, v: np.array([
+ 3*np.sin(u)*np.cos(v),
+ 3*np.sin(u)*np.sin(v),
+ 9*np.sin(u)*np.cos(v)*np.cos(v)*np.sin(v)
+ ]),u_min=0,u_max=PI,v_min=0,v_max=2*PI,checkerboard_colors=[YELLOW_C, YELLOW_E],
+ resolution=(15, 32)).scale(1)
+
+ continuity_func_copy1 = continuity_func.copy()
+ continuity_func_copy2 = continuity_func.copy()
+
+ continuity_func_x = ParametricSurface(
+ lambda u, v: np.array([
+ 3*np.sin(u)*np.cos(v),
+ 3*np.sin(u)*np.sin(v),
+ 9*np.sin(u)*np.cos(v)*np.cos(v)*np.sin(v)
+ ]),u_min=0,u_max=PI,v_min=PI,v_max=2*PI,checkerboard_colors=[YELLOW_C, YELLOW_E],
+ resolution=(15, 32)).scale(1)
+
+ continuity_func_y = ParametricSurface(
+ lambda u, v: np.array([
+ 3*np.sin(u)*np.cos(v),
+ 3*np.sin(u)*np.sin(v),
+ 9*np.sin(u)*np.cos(v)*np.cos(v)*np.sin(v)
+ ]),u_min=0,u_max=PI,v_min=PI/2,v_max=3*PI/2,checkerboard_colors=[YELLOW_C, YELLOW_E],
+ resolution=(15, 32)).scale(1)
+
+ continuity_x =ParametricFunction(
+ lambda u : np.array([
+ u,
+ 0,
+ 0
+ ]),color="#006400",t_min=-3,t_max=3,
+ )
+
+ continuity_y =ParametricFunction(
+ lambda u : np.array([
+ 0,
+ u,
+ 0
+ ]),color="#000080",t_min=-3,t_max=3,
+ )
+
+ plane_x = Polygon(np.array([-3,0,-3]),np.array([3,0,-3]),np.array([3,0,3]),np.array([-3,0,3]),np.array([-3,0,-3]), color = GREEN, fill_color = GREEN, fill_opacity = 0.2)
+ plane_x_text = TextMobject(r"$y = 0$", color = GREEN_C).move_to(1.7*UP + 3.8*RIGHT)
+
+ plane_y = Polygon(np.array([0,-3,-3]),np.array([0,3,-3]),np.array([0,3,3]),np.array([0,-3,3]),np.array([0,-3,-3]), color = BLUE, fill_color = BLUE, fill_opacity = 0.2)
+ plane_y_text = TextMobject(r"$x = 0$", color = BLUE_C).move_to(1.7*UP + 3.8*RIGHT)
+
+ origin_x = Polygon(*[np.array([0.05*np.cos(i*DEGREES),0,0.05*np.sin(i*DEGREES)]) for i in range(361)], color = "#000080", fill_color = "#000080", fill_opacity = 1).move_to(np.array([0,0,0]))
+ origin_x_text = TextMobject(r"$(0,0,0)$", color = RED_C).scale(0.7).move_to(np.array([-0.6,0,-0.5]))
+
+ origin_y = Polygon(*[np.array([0,0.05*np.cos(i*DEGREES),0.05*np.sin(i*DEGREES)]) for i in range(361)], color = "#006400", fill_color = "#006400", fill_opacity = 1).move_to(np.array([0,0,0]))
+ origin_y_text = TextMobject(r"$(0,0,0)$", color = RED_C).scale(0.7).move_to(np.array([0,-0.6,-0.5]))
+
+ self.set_camera_orientation(phi=80 * DEGREES, theta = 0*DEGREES)
+
+
+ self.add(axes)
+
+ axis = TextMobject(r"X",r"Y",r"Z")
+ axis[0].move_to(6*RIGHT)
+ axis[1].move_to(6*UP)
+ axis[2].move_to(3.7*UP)
+
+ self.add_fixed_in_frame_mobjects(axis[2])
+ self.add_fixed_orientation_mobjects(axis[0])
+ self.add_fixed_orientation_mobjects(axis[1])
+
+ self.play(ShowCreation(continuity_func))
+
+ self.move_camera(phi=80* DEGREES,theta=105*DEGREES)
+
+ self.play(ShowCreation(plane_x))
+ self.add_fixed_in_frame_mobjects(plane_x_text)
+ self.wait()
+ self.play(ReplacementTransform(continuity_func, continuity_func_x))
+ self.play(FadeOut(plane_x), FadeOut(plane_x_text))
+ self.play(ShowCreation(continuity_x), ShowCreation(origin_x))
+ self.add_fixed_orientation_mobjects(origin_x_text)
+
+ self.move_camera(phi=80* DEGREES,theta=15*DEGREES)
+ self.wait(3)
+
+ self.play(FadeOut(origin_x), FadeOut(origin_x_text), FadeOut(continuity_x), ReplacementTransform(continuity_func_x, continuity_func_copy1))
+ self.play(ShowCreation(plane_y))
+ self.add_fixed_in_frame_mobjects(plane_y_text)
+ self.wait()
+ self.play(ReplacementTransform(continuity_func_copy1, continuity_func_y))
+ self.play(FadeOut(plane_y), FadeOut(plane_y_text))
+ self.play(ShowCreation(continuity_y), ShowCreation(origin_y))
+ self.add_fixed_orientation_mobjects(origin_y_text)
+
+ self.move_camera(phi=80* DEGREES,theta=75*DEGREES)
+ self.wait(3)
+
+ self.play(FadeOut(origin_y), FadeOut(origin_y_text), FadeOut(continuity_y), ReplacementTransform(continuity_func_y, continuity_func_copy2))
+ self.wait(2) \ No newline at end of file
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/gifs/file1_epsilon_delta_defn.gif b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/gifs/file1_epsilon_delta_defn.gif
new file mode 100644
index 0000000..2378bcf
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/gifs/file1_epsilon_delta_defn.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/gifs/file2_limit_approach_point.gif b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/gifs/file2_limit_approach_point.gif
new file mode 100644
index 0000000..3abd596
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/gifs/file2_limit_approach_point.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/gifs/file3_limit_approach_point_3d.gif b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/gifs/file3_limit_approach_point_3d.gif
new file mode 100644
index 0000000..3e87cdd
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/gifs/file3_limit_approach_point_3d.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/gifs/file4_limit_different_point.gif b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/gifs/file4_limit_different_point.gif
new file mode 100644
index 0000000..9a831e4
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/gifs/file4_limit_different_point.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/gifs/file5_continuity_func.gif b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/gifs/file5_continuity_func.gif
new file mode 100644
index 0000000..2a0a61f
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/multivariable-limits-and-continuity/gifs/file5_continuity_func.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/README.md b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/README.md
new file mode 100644
index 0000000..c62dd51
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/README.md
@@ -0,0 +1,23 @@
+**file1_partial_deriv_gas_law**
+![file1_partial_deriv_gas_law](https://github.com/nishanpoojary/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file1_partial_deriv_gas_law.gif)
+
+**file2_partial_deriv_hill**
+![file2_partial_deriv_hill](https://github.com/nishanpoojary/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file2_partial_deriv_hill.gif)
+
+**file3_partial_deriv_defn**
+![file3_partial_deriv_defn](https://github.com/nishanpoojary/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file3_partial_deriv_defn.gif)
+
+**file4_partial_deriv_example**
+![file4_partial_deriv_example](https://github.com/nishanpoojary/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file4_partial_deriv_example.gif)
+
+**file5_partial_deriv_func_2maximas**
+![file5_partial_deriv_func_2maximas](https://github.com/nishanpoojary/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file5_partial_deriv_func_2maximas.gif)
+
+**file6_clariant_rule**
+![file6_clariant_rule](https://github.com/nishanpoojary/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file6_clariant_rule.gif)
+
+**file7_partial_deriv_clariant_rule**
+![file7_partial_deriv_clariant_rule](https://github.com/nishanpoojary/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file7_partial_deriv_clariant_rule.gif)
+
+**file8_chain_rule**
+![file8_chain_rule](https://github.com/nishanpoojary/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file8_chain_rule.gif)
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/file1_partial_deriv_gas_law.py b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/file1_partial_deriv_gas_law.py
new file mode 100644
index 0000000..3d35c97
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/file1_partial_deriv_gas_law.py
@@ -0,0 +1,88 @@
+from manimlib.imports import *
+
+class GasLaw(Scene):
+ def construct(self):
+ gas_law = TextMobject(r"$P$", r"$V$", r"=", r"$n$", r"$R$", r"$T$").scale(1.5)
+ gas_law[0].set_color(BLUE_C)
+ gas_law[1].set_color(GREEN_C)
+ gas_law[3].set_color(RED_C)
+ gas_law[4].set_color(ORANGE)
+ gas_law[5].set_color(YELLOW_C)
+
+ gas_law_trans = TexMobject("V", "=", "{n", "R", "T", "\\over", "P}").scale(1.5)
+ gas_law_trans[0].set_color(GREEN_C)
+ gas_law_trans[2].set_color(RED_C)
+ gas_law_trans[3].set_color(ORANGE)
+ gas_law_trans[4].set_color(YELLOW_C)
+ gas_law_trans[6].set_color(BLUE_C)
+
+ gas_law_func = TexMobject("V", "=", "f(", "n", ",", "T", ",", "P", ")").scale(1.5)
+ gas_law_func[0].set_color(GREEN_C)
+ gas_law_func[2].set_color(ORANGE)
+ gas_law_func[3].set_color(RED_C)
+ gas_law_func[5].set_color(YELLOW_C)
+ gas_law_func[7].set_color(BLUE_C)
+ gas_law_func[8].set_color(ORANGE)
+
+ partial_gas_law_func = TexMobject("{\\partial", "V","\\over", "\\partial", "P}", r"=", "{\\partial", "\\over", "\\partial", "P}", "f(", r"n", ",", r"T", ",", r"P", r")").scale(1.5)
+ partial_gas_law_func.set_color_by_tex("\\partial", PINK)
+ partial_gas_law_func.set_color_by_tex("P}", BLUE_C)
+
+ partial_gas_law_func[1].set_color(GREEN_C)
+ partial_gas_law_func[10].set_color(ORANGE)
+ partial_gas_law_func[11].set_color(RED_C)
+ partial_gas_law_func[13].set_color(YELLOW_C)
+ partial_gas_law_func[15].set_color(BLUE_C)
+ partial_gas_law_func[16].set_color(ORANGE)
+
+ partial_gas_law_trans = TexMobject("{\\partial", "V","\\over", "\\partial", "P}", r"=", "{\\partial", "\\over", "\\partial", "P}", "{n", "R", "T", "\\over", "P}").scale(1.5)
+ partial_gas_law_trans.set_color_by_tex("\\partial", PINK)
+ partial_gas_law_trans.set_color_by_tex("P}", BLUE_C)
+
+ partial_gas_law_trans[1].set_color(GREEN_C)
+ partial_gas_law_trans[10].set_color(RED_C)
+ partial_gas_law_trans[11].set_color(ORANGE)
+ partial_gas_law_trans[12].set_color(YELLOW_C)
+
+ partial_gas_law_trans2 = TexMobject("{\\partial", "V","\\over", "\\partial", "P}", r"=", "n", "R", "T", "{\\partial", "\\over", "\\partial", "P}", "P^{-1}",).scale(1.5)
+ partial_gas_law_trans2.set_color_by_tex("\\partial", PINK)
+ partial_gas_law_trans2.set_color_by_tex("P}", BLUE_C)
+
+ partial_gas_law_trans2[1].set_color(GREEN_C)
+ partial_gas_law_trans2[6].set_color(RED_C)
+ partial_gas_law_trans2[7].set_color(ORANGE)
+ partial_gas_law_trans2[8].set_color(YELLOW_C)
+ partial_gas_law_trans2[-1].set_color(BLUE_C)
+
+ partial_gas_law_trans3 = TexMobject("{\\partial", "V","\\over", "\\partial", "P}", r"=", "n", "R", "T", "P^{-2}",).scale(1.5)
+ partial_gas_law_trans3.set_color_by_tex("\\partial", PINK)
+ partial_gas_law_trans3.set_color_by_tex("P}", BLUE_C)
+
+ partial_gas_law_trans3[1].set_color(GREEN_C)
+ partial_gas_law_trans3[6].set_color(RED_C)
+ partial_gas_law_trans3[7].set_color(ORANGE)
+ partial_gas_law_trans3[8].set_color(YELLOW_C)
+ partial_gas_law_trans3[9].set_color(BLUE_C)
+
+ framebox = SurroundingRectangle(partial_gas_law_trans3, color = PURPLE, buff = 0.3)
+
+
+
+ self.play(Write(gas_law))
+ self.wait()
+ self.play(Transform(gas_law, gas_law_trans))
+ self.wait()
+ self.play(Transform(gas_law, gas_law_func))
+ self.wait()
+ self.play(Transform(gas_law, gas_law_trans))
+ self.wait()
+ self.play(Transform(gas_law, partial_gas_law_func))
+ self.wait()
+ self.play(Transform(gas_law, partial_gas_law_trans))
+ self.wait()
+ self.play(Transform(gas_law, partial_gas_law_trans2))
+ self.wait()
+ self.play(Transform(gas_law, partial_gas_law_trans3))
+ self.wait()
+ self.play(ShowCreation(framebox))
+ self.wait() \ No newline at end of file
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/file2_partial_deriv_hill.py b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/file2_partial_deriv_hill.py
new file mode 100644
index 0000000..bfb7687
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/file2_partial_deriv_hill.py
@@ -0,0 +1,122 @@
+from manimlib.imports import *
+
+class Hill(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes()
+
+ function = ParametricSurface(
+ lambda u, v: np.array([
+ 1.2*np.sin(u)*np.cos(v),
+ 1.2*np.sin(u)*np.sin(v),
+ -1.2*1.2*np.sin(u)*np.sin(u)*(1+0.5*np.sin(v)*np.sin(v))+2
+ ]),u_min=0,u_max=PI/2,v_min=0,v_max=2*PI,checkerboard_colors=[GREEN_C, GREEN_E],
+ resolution=(15, 32)).scale(1)
+
+ func_x =ParametricFunction(
+ lambda u : np.array([
+ u,
+ 0,
+ 2 - u*u
+ ]),color=RED_E,t_min=-1.2,t_max=1.2,
+ )
+
+ func_y =ParametricFunction(
+ lambda u : np.array([
+ 0,
+ u,
+ 2 - 1.5*u*u
+ ]),color=PINK,t_min=-1.2,t_max=1.2,
+ )
+
+ self.set_camera_orientation(phi=60 * DEGREES, theta = 0*DEGREES)
+ #self.set_camera_orientation(phi=45 * DEGREES, theta = -20*DEGREES)
+
+ self.add(axes)
+ axis = TextMobject(r"X",r"Y",r"Z")
+ axis[0].move_to(6*RIGHT)
+ axis[1].move_to(6*UP)
+ axis[2].move_to(np.array([0,0,3.7]))
+
+ self.add_fixed_orientation_mobjects(axis[2])
+ self.add_fixed_orientation_mobjects(axis[0])
+ self.add_fixed_orientation_mobjects(axis[1])
+
+ self.play(ShowCreation(function))
+ self.wait()
+
+ self.move_camera(phi=60 * DEGREES, theta = 45*DEGREES)
+ #self.play(ShowCreation(func_x))
+
+ text_x = TextMobject("Slope of the hill along", r"$x$", "axis", color = YELLOW_C).scale(0.6).move_to(2.7*UP + 3.5*RIGHT)
+ text_x[1].set_color(PINK)
+
+
+ slope_text_x = TexMobject("Slope =", "{\\partial", "f", "\\over", "\\partial", "x}").scale(0.6).move_to(2*UP + 3.5*RIGHT)
+ slope_text_x[0].set_color(BLUE_E)
+ slope_text_x.set_color_by_tex("\\partial",YELLOW_C)
+ slope_text_x.set_color_by_tex("f",RED_E)
+ slope_text_x[5].set_color(PINK)
+
+ self.add_fixed_in_frame_mobjects(text_x, slope_text_x)
+
+ dot_x = Dot().rotate(PI/2).set_color(YELLOW_E)
+ alpha_x = ValueTracker(0)
+ vector_x = self.get_tangent_vector(alpha_x.get_value(),func_x,scale=1.5)
+ dot_x.add_updater(lambda m: m.move_to(vector_x.get_center()))
+ self.play(
+ ShowCreation(func_x),
+ GrowFromCenter(dot_x),
+ GrowArrow(vector_x)
+ )
+ vector_x.add_updater(
+ lambda m: m.become(
+ self.get_tangent_vector(alpha_x.get_value()%1,func_x,scale=1.5)
+ )
+ )
+
+ self.add(vector_x,dot_x)
+
+ self.play(alpha_x.increment_value, 1, run_time=10, rate_func=linear)
+
+ #self.move_camera(phi=60 * DEGREES, theta = 0*DEGREES)
+ self.play(FadeOut(vector_x), FadeOut(dot_x), FadeOut(func_x), FadeOut(text_x), FadeOut(slope_text_x))
+
+ text_y = TextMobject("Slope of the hill along", r"$y$", "axis", color = YELLOW_C).scale(0.6).move_to(2.7*UP + 3.5*RIGHT)
+ text_y[1].set_color(RED_C)
+
+
+ slope_text_y = TexMobject("Slope =", "{\\partial", "f", "\\over", "\\partial", "x}").scale(0.6).move_to(2*UP + 3.5*RIGHT)
+ slope_text_y[0].set_color(BLUE_E)
+ slope_text_y.set_color_by_tex("\\partial",YELLOW_C)
+ slope_text_y.set_color_by_tex("f",PINK)
+ slope_text_y[5].set_color(RED_C)
+
+ self.add_fixed_in_frame_mobjects(text_y, slope_text_y)
+
+ dot_y = Dot().rotate(PI/2).set_color(BLUE_E)
+ alpha_y = ValueTracker(0)
+ vector_y = self.get_tangent_vector(alpha_y.get_value(),func_y,scale=1.5)
+ dot_y.add_updater(lambda m: m.move_to(vector_y.get_center()))
+ self.play(
+ ShowCreation(func_y),
+ GrowFromCenter(dot_y),
+ GrowArrow(vector_y)
+ )
+ vector_y.add_updater(
+ lambda m: m.become(
+ self.get_tangent_vector(alpha_y.get_value()%1,func_y,scale=1.5)
+ )
+ )
+
+ self.add(vector_y,dot_y)
+ self.play(alpha_y.increment_value, 1, run_time=10, rate_func=linear)
+ self.play(FadeOut(vector_y), FadeOut(dot_y), FadeOut(func_y), FadeOut(text_y), FadeOut(slope_text_y))
+ self.wait(2)
+
+ def get_tangent_vector(self, proportion, curve, dx=0.001, scale=1):
+ coord_i = curve.point_from_proportion(proportion)
+ coord_f = curve.point_from_proportion(proportion + dx)
+ reference_line = Line(coord_i,coord_f)
+ unit_vector = reference_line.get_unit_vector() * scale
+ vector = Line(coord_i - unit_vector, coord_i + unit_vector, color = ORANGE, buff=0)
+ return vector \ No newline at end of file
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/file3_partial_deriv_defn.py b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/file3_partial_deriv_defn.py
new file mode 100644
index 0000000..a25ca56
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/file3_partial_deriv_defn.py
@@ -0,0 +1,218 @@
+from manimlib.imports import *
+
+class PartialDeriv(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes()
+
+ paraboloid = ParametricSurface(
+ lambda u, v: np.array([
+ 2*np.sin(u)*np.cos(v),
+ 2*np.sin(u)*np.sin(v),
+ -2*2*np.sin(u)*np.sin(u)+2
+ ]),u_min=0,u_max=PI/2,v_min=0,v_max=2*PI,checkerboard_colors=[PINK, PURPLE],
+ resolution=(15, 32)).scale(1)
+
+ paraboloid_copy1 = paraboloid.copy()
+ paraboloid_copy2 = paraboloid.copy()
+
+ paraboloid_x = ParametricSurface(
+ lambda u, v: np.array([
+ 2*np.sin(u)*np.cos(v),
+ 2*np.sin(u)*np.sin(v),
+ -2*2*np.sin(u)*np.sin(u)+2
+ ]),u_min=0,u_max=PI/2,v_min=PI,v_max=2*PI,checkerboard_colors=[PINK, PURPLE],
+ resolution=(15, 32)).scale(1)
+
+ paraboloid_x_copy = paraboloid_x.copy()
+
+ paraboloid_y = ParametricSurface(
+ lambda u, v: np.array([
+ 2*np.sin(u)*np.cos(v),
+ 2*np.sin(u)*np.sin(v),
+ -2*2*np.sin(u)*np.sin(u)+2
+ ]),u_min=0,u_max=PI/2,v_min=PI/2,v_max=3*PI/2,checkerboard_colors=[PINK, PURPLE],
+ resolution=(15, 32)).scale(1)
+
+ parabola1 =ParametricFunction(
+ lambda u : np.array([
+ u,
+ 0,
+ -(u*u) + 2
+ ]),color="#006400",t_min=-2,t_max=2,
+ )
+ parabola2 =ParametricFunction(
+ lambda u : np.array([
+ 0,
+ u,
+ -(u*u) + 2
+ ]),color=BLUE_C,t_min=-2,t_max=2,
+ )
+
+ plane1 = Polygon(np.array([-2.2,0,-2.5]),np.array([2.2,0,-2.5]),np.array([2.2,0,2.5]),np.array([-2.2,0,2.5]),np.array([-2.2,0,-2.5]), color = GREEN, fill_color = GREEN, fill_opacity = 0.2)
+ plane1_text = TextMobject(r"$y = 0$", color = GREEN_C).move_to(2*UP + 3.3*RIGHT)
+
+ plane2 = Polygon(np.array([0,-2.2,-2.5]),np.array([0,2.2,-2.5]),np.array([0,2.2,2.5]),np.array([0,-2.2,2.5]),np.array([0,-2.2,-2.5]), color = BLUE, fill_color = BLUE, fill_opacity = 0.2)
+ plane2_text = TextMobject(r"$x = 0$", color = BLUE_C).move_to(2*UP + 3.2*RIGHT)
+
+ surface_eqn = TextMobject("Surface", r"$z = 2- x^2 -y^2$", color = YELLOW_C).scale(0.6).move_to(np.array([3*LEFT +3*UP]))
+ surface_eqn[0].set_color(PINK)
+
+ dot1 =Sphere(radius=0.08).move_to(np.array([-1,0,1]))
+ dot1.set_fill(RED)
+ line1 = Line(np.array([-1.55, 0,0]), np.array([-0.4, 0,2.2]), color = RED)
+ lab_x = TextMobject(r"$f(x_0,y_0)$", color = RED).scale(0.7)
+ para_lab_x = TextMobject(r"$f(x,y_0)$", color = "#006400").scale(0.7)
+ tangent_line_x = TextMobject("Tangent Line", color = RED_C, buff = 0.4).scale(0.6).move_to(np.array([1.7*RIGHT +1.8*UP]))
+
+
+ text1 = TextMobject(r"$\frac{\partial f}{\partial x}\vert_{(x_0,y_0)} = \frac{d}{dx}$", r"$f(x,y_0)$", r"$\vert_{x=x_0}$").scale(0.6)
+ brace1 = Brace(text1[1], DOWN, buff = SMALL_BUFF, color = GREEN)
+ t1 = brace1.get_text("Just depends on x")
+ t1.scale(0.6)
+ t1.set_color(GREEN)
+
+
+ dot2 =Sphere(radius=0.08).move_to(np.array([0,1,1]))
+ dot2.set_fill(RED)
+ line2 = Line(np.array([0, 1.55,0]), np.array([0, 0.4,2.2]), color = RED)
+ lab_y = TextMobject(r"$f(x_0,y_0)$", color = RED).scale(0.7)
+ para_lab_y = TextMobject(r"$f(x_0,y)$", color = BLUE_C).scale(0.7)
+ tangent_line_y = TextMobject("Tangent Line", color = RED_C, buff = 0.4).scale(0.6).move_to(np.array([1.7*RIGHT +1.8*UP]))
+
+ text2 = TextMobject(r"$\frac{\partial f}{\partial y}\vert_{(x_0,y_0)} = \frac{d}{dy}$", r"$f(x_0,y)$", r"$\vert_{y=y_0}$").scale(0.6)
+ brace2 = Brace(text2[1], DOWN, buff = SMALL_BUFF, color = GREEN)
+ t2 = brace2.get_text("Just depends on y")
+ t2.scale(0.6)
+ t2.set_color(GREEN)
+
+ text3 = TextMobject(r"$= \lim_{h \to 0} \frac{f(x_0+h,y_0) - f(x_0,y_0)}{h}$").scale(0.6)
+
+ dot3 =Sphere(radius=0.08).move_to(np.array([-1.22,0,0.5]))
+ dot3.set_fill(YELLOW_C)
+ line3 = Line(np.array([-1.44,0,0]), np.array([-0.6,0,2.2]), color = YELLOW_C)
+ lab_line3 = TextMobject(r"$f(x_0+h,y_0)$", color = YELLOW_C).scale(0.7)
+
+
+ self.set_camera_orientation(phi=80 * DEGREES, theta = 0*DEGREES)
+ #self.set_camera_orientation(phi=80 * DEGREES, theta = 20*DEGREES)
+ #self.begin_ambient_camera_rotation(rate=0.3)
+
+
+ self.add(axes)
+
+ axis = TextMobject(r"X",r"Y",r"Z")
+ axis[0].move_to(6*RIGHT)
+ axis[1].move_to(6*UP)
+ axis[2].move_to(3.7*UP)
+
+ self.add_fixed_in_frame_mobjects(axis[2])
+ #self.add_fixed_orientation_mobjects(axis[2])
+
+ self.play(Write(paraboloid))
+
+ self.add_fixed_in_frame_mobjects(surface_eqn)
+ #self.move_camera(phi=80* DEGREES,theta=110*DEGREES)
+ self.move_camera(phi=80* DEGREES,theta=45*DEGREES)
+
+ self.add_fixed_orientation_mobjects(axis[0])
+ self.add_fixed_orientation_mobjects(axis[1])
+ self.play(ShowCreation(plane1))
+ self.add_fixed_in_frame_mobjects(plane1_text)
+ self.wait()
+ self.play(ReplacementTransform(paraboloid, paraboloid_x))
+
+ lab_x.move_to(np.array([1.8*RIGHT +1.15*UP]))
+ para_lab_x.move_to(np.array([1.3*LEFT +1.6*UP]))
+ self.wait()
+ self.play(FadeOut(plane1), FadeOut(plane1_text))
+ self.play(ShowCreation(parabola1))
+ self.add_fixed_in_frame_mobjects(para_lab_x)
+ self.play(ShowCreation(dot1))
+ self.add_fixed_in_frame_mobjects(lab_x)
+ #self.play(ShowCreation(dot1))
+ self.wait()
+ self.play(ShowCreation(line1))
+ self.add_fixed_in_frame_mobjects(tangent_line_x)
+ self.wait()
+
+ self.add_fixed_in_frame_mobjects(text1, brace1, t1)
+ grp1 = VGroup(text1, brace1, t1)
+ grp1.move_to(3*UP+3*RIGHT)
+ self.play(Write(text1),GrowFromCenter(brace1), FadeIn(t1))
+ self.wait()
+ self.play(FadeOut(parabola1), FadeOut(line1), FadeOut(lab_x), FadeOut(para_lab_x), FadeOut(dot1), FadeOut(tangent_line_x),FadeOut(grp1))
+
+
+
+
+ #self.move_camera(phi=80* DEGREES,theta=20*DEGREES)
+
+ self.play(ReplacementTransform(paraboloid_x, paraboloid_copy1))
+ self.wait()
+ self.play(ShowCreation(plane2))
+ self.add_fixed_in_frame_mobjects(plane2_text)
+ self.wait()
+ self.play(ReplacementTransform(paraboloid_copy1, paraboloid_y))
+
+ lab_y.move_to(np.array([1.8*RIGHT +1.15*UP]))
+ para_lab_y.move_to(np.array([1.3*LEFT +1.6*UP]))
+ self.wait()
+ self.play(FadeOut(plane2), FadeOut(plane2_text))
+ self.play(ShowCreation(parabola2))
+ self.add_fixed_in_frame_mobjects(para_lab_y)
+ self.play(ShowCreation(dot2))
+ self.add_fixed_in_frame_mobjects(lab_y)
+ self.wait()
+ self.play(ShowCreation(line2))
+ self.add_fixed_in_frame_mobjects(tangent_line_y)
+ self.wait()
+
+ self.add_fixed_in_frame_mobjects(text2, brace2, t2)
+ grp2 = VGroup(text2, brace2, t2)
+ grp2.move_to(3*UP+3*RIGHT)
+ self.play(Write(text2),GrowFromCenter(brace2), FadeIn(t2))
+ self.wait()
+ self.play(FadeOut(parabola2), FadeOut(line2), FadeOut(lab_y), FadeOut(para_lab_y), FadeOut(dot2), FadeOut(tangent_line_y), FadeOut(grp2))
+ self.wait()
+
+
+ #self.move_camera(phi=80* DEGREES,theta=105*DEGREES)
+ self.play(ReplacementTransform(paraboloid_y, paraboloid_copy2))
+ self.wait()
+
+
+ self.play(ShowCreation(plane1))
+ self.add_fixed_in_frame_mobjects(plane1_text)
+ self.wait()
+ self.play(ReplacementTransform(paraboloid_copy2, paraboloid_x_copy))
+
+ lab_x.move_to(np.array([1.8*RIGHT +1.15*UP]))
+ para_lab_x.move_to(np.array([1.3*LEFT +1.6*UP]))
+ lab_line3.move_to(np.array([2.4*RIGHT +0.5*UP]))
+ self.wait()
+ self.play(FadeOut(plane1), FadeOut(plane1_text))
+ self.play(ShowCreation(parabola1))
+ self.add_fixed_in_frame_mobjects(para_lab_x)
+ self.play(ShowCreation(dot1))
+ self.add_fixed_in_frame_mobjects(lab_x)
+ self.play(ShowCreation(dot3))
+ self.add_fixed_in_frame_mobjects(lab_line3)
+ self.wait()
+ self.play(ShowCreation(line1))
+ self.add_fixed_in_frame_mobjects(tangent_line_x)
+ self.play(ShowCreation(line3))
+ self.wait()
+
+
+ self.add_fixed_in_frame_mobjects(text1,text3)
+ text1.move_to(3*UP+3*RIGHT)
+ text3.next_to(text1, DOWN)
+ self.play(Write(text1),Write(text3))
+ self.wait()
+ self.play(FadeOut(parabola1), FadeOut(line1), FadeOut(lab_x), FadeOut(line3), FadeOut(lab_line3), FadeOut(para_lab_x), FadeOut(dot1), FadeOut(dot3), FadeOut(tangent_line_x), FadeOut(text1), FadeOut(text3))
+ self.wait()
+
+
+
+
+
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/file4_partial_deriv_example.py b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/file4_partial_deriv_example.py
new file mode 100644
index 0000000..5712a62
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/file4_partial_deriv_example.py
@@ -0,0 +1,246 @@
+from manimlib.imports import *
+
+class PartialDerivX(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes()
+
+ paraboloid = ParametricSurface(
+ lambda u, v: np.array([
+ 2*np.sin(u)*np.cos(v),
+ 2*np.sin(u)*np.sin(v),
+ -2*2*np.sin(u)*np.sin(u)+2
+ ]),u_min=0,u_max=PI/2,v_min=0,v_max=2*PI,checkerboard_colors=[PINK, PURPLE],
+ resolution=(15, 32)).scale(1)
+
+ paraboloid_copy = paraboloid.copy()
+
+
+ paraboloid_x = ParametricSurface(
+ lambda u, v: np.array([
+ 2*np.sin(u)*np.cos(v),
+ 2*np.sin(u)*np.sin(v),
+ -2*2*np.sin(u)*np.sin(u)+2
+ ]),u_min=0,u_max=PI/2,v_min=PI,v_max=2*PI,checkerboard_colors=[PINK, PURPLE],
+ resolution=(15, 32)).scale(1)
+
+
+ parabola =ParametricFunction(
+ lambda u : np.array([
+ u,
+ 0,
+ -(u*u) + 2
+ ]),color="#006400",t_min=-2,t_max=2,
+ )
+
+ plane = Polygon(np.array([-2.2,0,-2.5]),np.array([2.2,0,-2.5]),np.array([2.2,0,2.5]),np.array([-2.2,0,2.5]),np.array([-2.2,0,-2.5]), color = GREEN, fill_color = GREEN, fill_opacity = 0.2)
+ plane_text = TextMobject(r"$y = 0$", color = GREEN_C).move_to(2*UP + 3*RIGHT)
+
+ surface_eqn = TextMobject("Surface", r"$z = 2- x^2 -y^2$", color = PINK).scale(0.6).move_to(np.array([3*LEFT +3*UP]))
+ surface_eqn[0].set_color(BLUE_C)
+
+ line = Line(np.array([-2,0,0]), np.array([2,0,0]), color = RED_C)
+
+
+ self.add(axes)
+
+ axis = TextMobject(r"X",r"Y",r"Z")
+ axis[0].move_to(6*RIGHT)
+ axis[1].move_to(6*UP)
+ axis[2].move_to(3.7*UP)
+
+ self.add_fixed_in_frame_mobjects(axis[2])
+ self.add_fixed_orientation_mobjects(axis[0])
+ self.add_fixed_orientation_mobjects(axis[1])
+
+
+ self.set_camera_orientation(phi=80 * DEGREES, theta = 0*DEGREES)
+
+ self.play(Write(paraboloid))
+
+ self.add_fixed_in_frame_mobjects(surface_eqn)
+ #self.move_camera(phi=80* DEGREES,theta=95*DEGREES)
+ self.move_camera(phi=80* DEGREES,theta=45*DEGREES)
+ self.play(ShowCreation(plane))
+ self.add_fixed_in_frame_mobjects(plane_text)
+ self.wait()
+ self.play(ReplacementTransform(paraboloid, paraboloid_x))
+ self.play(FadeOut(plane), FadeOut(plane_text))
+ self.play(ShowCreation(parabola), ShowCreation(line))
+
+ text1 = TextMobject("Moving small", r"$dx$", r"steps").scale(0.6).move_to(3*UP + 3.5*RIGHT).set_color_by_gradient(RED, ORANGE, YELLOW, BLUE, PURPLE)
+
+ text2 = TextMobject("Observing change in function, keeping", r"$y$", r"constant").scale(0.6).move_to(2.6*UP + 3.5*RIGHT).set_color_by_gradient(RED, ORANGE, YELLOW, GREEN, BLUE, PURPLE)
+
+ slope_text = TexMobject("Slope =", "{\\partial", "f", "\\over", "\\partial", "x}").scale(0.6).move_to(2*UP + 3.5*RIGHT)
+ slope_text[0].set_color(BLUE_E)
+ slope_text.set_color_by_tex("\\partial",PINK)
+ slope_text.set_color_by_tex("f","#006400")
+ slope_text[5].set_color(RED_C)
+
+ self.add_fixed_in_frame_mobjects(text1, text2)
+ self.wait()
+ self.add_fixed_in_frame_mobjects(slope_text)
+ #add_fixed_orientation_mobjects
+
+
+ dot = Dot().rotate(PI/2).set_color(RED_C)
+ alpha = ValueTracker(0)
+ vector = self.get_tangent_vector(alpha.get_value(),parabola,scale=1.5)
+ dot.add_updater(lambda m: m.move_to(vector.get_center()))
+ self.play(
+ ShowCreation(parabola),
+ GrowFromCenter(dot),
+ GrowArrow(vector)
+ )
+ vector.add_updater(
+ lambda m: m.become(
+ self.get_tangent_vector(alpha.get_value()%1,parabola,scale=1.5)
+ )
+ )
+ self.add(vector,dot)
+ self.play(alpha.increment_value, 1, run_time=10, rate_func=linear)
+ self.wait()
+
+
+ '''
+ for i in np.arange(-2,2,0.2):
+ self.play(ReplacementTransform(Line(np.array([i,0,0]), np.array([i,0,-i*i + 2]), color = GREEN_C), Line(np.array([i+0.2,0,0]), np.array([i+0.2,0,-(i+0.2)**2 + 2]), color = GREEN_C)))
+ #self.wait()
+ '''
+
+ self.wait()
+ self.play(FadeOut(parabola), FadeOut(line), FadeOut(vector), FadeOut(dot), FadeOut(text1), FadeOut(text2), FadeOut(slope_text),FadeOut(surface_eqn))
+
+ #self.move_camera(phi=80* DEGREES,theta= 0*DEGREES)
+ self.play(ReplacementTransform(paraboloid_x, paraboloid_copy))
+ self.wait()
+
+
+ def get_tangent_vector(self, proportion, curve, dx=0.001, scale=1):
+ coord_i = curve.point_from_proportion(proportion)
+ coord_f = curve.point_from_proportion(proportion + dx)
+ reference_line = Line(coord_i,coord_f)
+ unit_vector = reference_line.get_unit_vector() * scale
+ vector = Line(coord_i - unit_vector, coord_i + unit_vector, color = BLUE_E, buff=0)
+ return vector
+
+
+class PartialDerivY(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes()
+
+ paraboloid = ParametricSurface(
+ lambda u, v: np.array([
+ 2*np.sin(u)*np.cos(v),
+ 2*np.sin(u)*np.sin(v),
+ -2*2*np.sin(u)*np.sin(u)+2
+ ]),u_min=0,u_max=PI/2,v_min=0,v_max=2*PI,checkerboard_colors=[PINK, PURPLE],
+ resolution=(15, 32)).scale(1)
+
+ paraboloid_copy = paraboloid.copy()
+
+
+ paraboloid_y = ParametricSurface(
+ lambda u, v: np.array([
+ 2*np.sin(u)*np.cos(v),
+ 2*np.sin(u)*np.sin(v),
+ -2*2*np.sin(u)*np.sin(u)+2
+ ]),u_min=0,u_max=PI/2,v_min=PI/2,v_max=3*PI/2,checkerboard_colors=[PINK, PURPLE],
+ resolution=(15, 32)).scale(1)
+
+
+ parabola =ParametricFunction(
+ lambda u : np.array([
+ 0,
+ u,
+ -(u*u) + 2
+ ]),color=YELLOW_C,t_min=-2,t_max=2,
+ )
+
+ plane = Polygon(np.array([0,-2.2,-2.5]),np.array([0,2.2,-2.5]),np.array([0,2.2,2.5]),np.array([0,-2.2,2.5]),np.array([0,-2.2,-2.5]), color = BLUE, fill_color = BLUE, fill_opacity = 0.2)
+ plane_text = TextMobject(r"$x = 0$", color = BLUE_C).move_to(2*UP + 3*RIGHT)
+
+ surface_eqn = TextMobject("Surface", r"$z = 2- x^2 -y^2$", color = PINK).scale(0.6).move_to(np.array([3*LEFT +3*UP]))
+ surface_eqn[0].set_color(BLUE_C)
+
+ line = Line(np.array([0,-2,0]), np.array([0,2,0]), color = RED_C)
+
+ self.add(axes)
+
+ axis = TextMobject(r"X",r"Y",r"Z")
+ axis[0].move_to(6*RIGHT)
+ axis[1].move_to(6*UP)
+ axis[2].move_to(3.7*UP)
+
+ self.add_fixed_in_frame_mobjects(axis[2])
+ self.add_fixed_orientation_mobjects(axis[0])
+ self.add_fixed_orientation_mobjects(axis[1])
+
+ self.set_camera_orientation(phi=80 * DEGREES, theta = 45*DEGREES)
+
+ self.play(Write(paraboloid))
+
+ self.add_fixed_in_frame_mobjects(surface_eqn)
+ #self.move_camera(phi=80* DEGREES,theta=5*DEGREES)
+ self.play(ShowCreation(plane))
+ self.add_fixed_in_frame_mobjects(plane_text)
+ self.wait()
+ self.play(ReplacementTransform(paraboloid, paraboloid_y))
+ self.play(FadeOut(plane), FadeOut(plane_text))
+ self.play(ShowCreation(parabola), ShowCreation(line))
+
+ text1 = TextMobject("Moving small", r"$dy$", r"steps").scale(0.6).move_to(3*UP + 3.5*RIGHT).set_color_by_gradient(RED, ORANGE, YELLOW, BLUE, PURPLE)
+
+ text2 = TextMobject("Observing change in function, keeping", r"$x$", r"constant").scale(0.6).move_to(2.6*UP + 3.5*RIGHT).set_color_by_gradient(RED, ORANGE, YELLOW, GREEN, BLUE, PURPLE)
+
+ slope_text = TexMobject("Slope =", "{\\partial", "f", "\\over", "\\partial", "y}").scale(0.6).move_to(2*UP + 3.5*RIGHT)
+ slope_text[0].set_color("#006400")
+ slope_text.set_color_by_tex("\\partial",PINK)
+ slope_text.set_color_by_tex("f",YELLOW_C)
+ slope_text[5].set_color(RED_C)
+
+ self.add_fixed_in_frame_mobjects(text1, text2)
+ self.wait()
+ self.add_fixed_in_frame_mobjects(slope_text)
+
+ dot = Dot().rotate(PI/2).set_color(RED_C)
+ alpha = ValueTracker(0)
+ vector = self.get_tangent_vector(alpha.get_value(),parabola,scale=1.5)
+ dot.add_updater(lambda m: m.move_to(vector.get_center()))
+ self.play(
+ ShowCreation(parabola),
+ GrowFromCenter(dot),
+ GrowArrow(vector)
+ )
+ vector.add_updater(
+ lambda m: m.become(
+ self.get_tangent_vector(alpha.get_value()%1,parabola,scale=1.5)
+ )
+ )
+ self.add(vector,dot)
+ self.play(alpha.increment_value, 1, run_time=10, rate_func=linear)
+ self.wait()
+
+ '''
+ for i in np.arange(-2,2,0.2):
+ self.play(ReplacementTransform(Line(np.array([0,i,0]), np.array([0,i,-i*i + 2]), color = BLUE_C), Line(np.array([0,i+0.2,0]), np.array([0,i+0.2,-(i+0.2)**2 + 2]), color = BLUE_C)))
+ #self.wait()
+ '''
+
+
+ self.wait()
+ self.play(FadeOut(parabola), FadeOut(line), FadeOut(vector), FadeOut(dot), FadeOut(text1), FadeOut(text2), FadeOut(slope_text),FadeOut(surface_eqn))
+
+ #self.move_camera(phi=80* DEGREES,theta= 90*DEGREES)
+ self.play(ReplacementTransform(paraboloid_y, paraboloid_copy))
+ self.wait()
+
+ def get_tangent_vector(self, proportion, curve, dx=0.001, scale=1):
+ coord_i = curve.point_from_proportion(proportion)
+ coord_f = curve.point_from_proportion(proportion + dx)
+ reference_line = Line(coord_i,coord_f)
+ unit_vector = reference_line.get_unit_vector() * scale
+ vector = Line(coord_i - unit_vector, coord_i + unit_vector, color = "#006400", buff=0)
+ return vector
+
+ \ No newline at end of file
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/file5_partial_deriv_func_2maximas.py b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/file5_partial_deriv_func_2maximas.py
new file mode 100644
index 0000000..7bbb9a7
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/file5_partial_deriv_func_2maximas.py
@@ -0,0 +1,227 @@
+from manimlib.imports import *
+
+class MaximaMinima(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes()
+
+ paraboloid = ParametricSurface(
+ lambda u, v: np.array([
+ 3.5*np.sin(u)*np.cos(v),
+ 3.5*np.sin(u)*np.sin(v),
+ 3.5*3.5*np.sin(u)*np.sin(u)*(1+2*np.sin(v)*np.sin(v))*np.exp(1 - 3.5*3.5*np.sin(u)*np.sin(u) )
+ ]),u_min=0,u_max=PI,v_min=0,v_max=2*PI, color = BLUE_C, fill_color = BLUE_C, fill_opacity = 0.1,
+ resolution=(15, 32)).scale(1)
+
+ paraboloid_copy1 = paraboloid.copy()
+ paraboloid_copy2 = paraboloid.copy()
+
+ paraboloid_x = ParametricSurface(
+ lambda u, v: np.array([
+ 3.5*np.sin(u)*np.cos(v),
+ 3.5*np.sin(u)*np.sin(v),
+ 3.5*3.5*np.sin(u)*np.sin(u)*(1+2*np.sin(v)*np.sin(v))*np.exp(1 - 3.5*3.5*np.sin(u)*np.sin(u) )
+ ]),u_min=0,u_max=PI,v_min=PI,v_max=2*PI, color = BLUE_C, fill_color = BLUE_C, fill_opacity = 0.1,
+ resolution=(15, 32)).scale(1)
+
+ paraboloid_y = ParametricSurface(
+ lambda u, v: np.array([
+ 3.5*np.sin(u)*np.cos(v),
+ 3.5*np.sin(u)*np.sin(v),
+ 3.5*3.5*np.sin(u)*np.sin(u)*(1+2*np.sin(v)*np.sin(v))*np.exp(1 - 3.5*3.5*np.sin(u)*np.sin(u) )
+ ]),u_min=0,u_max=PI,v_min=PI/2,v_max=3*PI/2, color = BLUE_C, fill_color = BLUE_C, fill_opacity = 0.1,
+ resolution=(15, 32)).scale(1)
+
+ parabola_x_out =ParametricFunction(
+ lambda u : np.array([
+ u,
+ 0,
+ (u*u )*np.exp(1-u*u)
+ ]),color=RED_E,t_min=-3.5,t_max=3.5,
+ )
+
+ parabola_y_out =ParametricFunction(
+ lambda u : np.array([
+ 0,
+ u,
+ (3*u*u)*np.exp(1-u*u)
+ ]),color=PINK,t_min=-3.5,t_max=3.5,
+ )
+
+ plane1 = Polygon(np.array([-3.5,0,-3]),np.array([3.5,0,-3]),np.array([3.5,0,3]),np.array([-3.5,0,3]),np.array([-3.5,0,-3]), color = RED_C, fill_color = RED_C, fill_opacity = 0.2)
+ plane_text_x = TextMobject(r"$y = 0$", color = RED_C).move_to(2*UP + 4.5*RIGHT)
+
+ plane2 = Polygon(np.array([0,-3.5,-3]),np.array([0,3.5,-3]),np.array([0,3.5,3]),np.array([0,-3.5,3]),np.array([0,-3.5,-3]), color = PINK, fill_color = PINK, fill_opacity = 0.2)
+ plane_text_y = TextMobject(r"$x = 0$", color = PINK).move_to(2*UP + 4.5*RIGHT)
+
+ surface_eqn = TextMobject("Surface", r"$z = (x^2 + 3y^2)e^{(1 - x^2 - y^2)}$", color = YELLOW_C).scale(0.6).move_to(np.array([3.5*LEFT +3.5*UP]))
+ surface_eqn[0].set_color(BLUE_C)
+
+ self.set_camera_orientation(phi=60 * DEGREES, theta = 45*DEGREES)
+
+ self.add(axes)
+ axis = TextMobject(r"X",r"Y",r"Z")
+ axis[0].move_to(6*RIGHT)
+ axis[1].move_to(6*UP)
+ axis[2].move_to(np.array([0,0,3.7]))
+
+ self.add_fixed_orientation_mobjects(axis[2])
+ self.add_fixed_orientation_mobjects(axis[0])
+ self.add_fixed_orientation_mobjects(axis[1])
+
+ self.play(ShowCreation(paraboloid))
+
+
+ #self.move_camera(phi=60 * DEGREES, theta = 45*DEGREES,run_time=3)
+
+
+ plane_x = Polygon(np.array([-3.5,2,-3]),np.array([3.5,2,-3]),np.array([3.5,2,3]),np.array([-3.5,2,3]),np.array([-3.5,2,-3]), color = YELLOW_C, fill_color = YELLOW_A, fill_opacity = 0.2)
+
+ plane_y = Polygon(np.array([2,-3.5,-3]),np.array([2,3.5,-3]),np.array([2,3.5,3]),np.array([2,-3.5,3]),np.array([2,-3.5,-3]), color = GREEN_C, fill_color = GREEN_A, fill_opacity = 0.2)
+
+ text_x = TextMobject(r"$x$", "is fixed on this" ,"plane").scale(0.7).to_corner(UL)
+ text_y = TextMobject(r"$y$", "is fixed on this" ,"plane").scale(0.7).to_corner(UR)
+
+ text_x[0].set_color(RED_C)
+ text_y[0].set_color(PINK)
+ text_x[1].set_color(BLUE_C)
+ text_y[1].set_color(BLUE_C)
+ text_x[2].set_color(GREEN_C)
+ text_y[2].set_color(YELLOW_C)
+
+ self.add_fixed_in_frame_mobjects(text_x, text_y)
+
+ for i in range(2,-4,-1):
+
+ parabola_x =ParametricFunction(lambda u : np.array([u,i,(u*u + 3*i*i)*np.exp(1- u*u - i*i)]),color=RED_C,t_min=-3.5,t_max=3.5,)
+
+ parabola_y =ParametricFunction(lambda u : np.array([i,u,(i*i + 3*u*u)*np.exp(1- u*u - i*i)]),color=PINK,t_min=-3.5,t_max=3.5,)
+
+ if(i==2):
+ self.play(ShowCreation(plane_x), ShowCreation(plane_y))
+ parabola_copy_x = parabola_x.copy()
+ parabola_copy_y = parabola_y.copy()
+
+
+ self.play(ShowCreation(parabola_copy_x), ShowCreation(parabola_copy_y))
+ self.wait()
+ self.play(FadeOut(parabola_copy_x), FadeOut(parabola_copy_y))
+
+ else:
+ self.play(ApplyMethod(plane_x.move_to, np.array([0,i,0])),ReplacementTransform(parabola_copy_x, parabola_x),ApplyMethod(plane_y.move_to, np.array([i,0,0])),ReplacementTransform(parabola_copy_y, parabola_y))
+ self.play(FadeOut(parabola_x), FadeOut(parabola_y))
+ self.wait()
+
+ parabola_copy_x = parabola_x.copy()
+ parabola_copy_y = parabola_y.copy()
+
+ self.play(FadeOut(plane_x), FadeOut(plane_y), FadeOut(text_x), FadeOut(text_y))
+
+
+ self.add_fixed_in_frame_mobjects(surface_eqn)
+
+ self.move_camera(phi=80 * DEGREES, theta = 95*DEGREES)
+
+ self.play(ShowCreation(plane1))
+ self.add_fixed_in_frame_mobjects(plane_text_x)
+ self.wait()
+ self.play(ReplacementTransform(paraboloid, paraboloid_x))
+ self.play(FadeOut(plane1), FadeOut(plane_text_x))
+
+ line_x = Line(np.array([-3.5,0,0]), np.array([3.5,0,0]), color = YELLOW_E)
+
+ self.play(ShowCreation(parabola_x_out), ShowCreation(line_x))
+
+ slope_text_x = TexMobject("Slope =", "{\\partial", "f", "\\over", "\\partial", "x}").scale(0.6).move_to(2*UP + 3.5*RIGHT)
+ slope_text_x[0].set_color(ORANGE)
+ slope_text_x.set_color_by_tex("\\partial",GREEN_E)
+ slope_text_x.set_color_by_tex("f",RED_E)
+ slope_text_x[5].set_color(YELLOW_E)
+
+ self.add_fixed_in_frame_mobjects(slope_text_x)
+
+
+ dot_x = Dot().rotate(PI/2).set_color(YELLOW_E)
+ alpha_x = ValueTracker(0)
+ vector_x = self.get_tangent_vector(alpha_x.get_value(),parabola_x_out,scale=1.5)
+ dot_x.add_updater(lambda m: m.move_to(vector_x.get_center()))
+ self.play(
+ ShowCreation(parabola_x_out),
+ GrowFromCenter(dot_x),
+ GrowArrow(vector_x)
+ )
+ vector_x.add_updater(
+ lambda m: m.become(
+ self.get_tangent_vector(alpha_x.get_value()%1,parabola_x_out,scale=1.5)
+ )
+ )
+ self.add(vector_x,dot_x)
+ self.play(alpha_x.increment_value, 1, run_time=10, rate_func=linear)
+
+ self.wait(2)
+ self.play(FadeOut(parabola_x_out), FadeOut(line_x), FadeOut(vector_x), FadeOut(dot_x), FadeOut(slope_text_x))
+
+ self.move_camera(phi=80* DEGREES,theta= 5*DEGREES)
+ self.play(ReplacementTransform(paraboloid_x, paraboloid_copy1))
+ self.wait()
+
+
+
+ self.play(ShowCreation(plane2))
+ self.add_fixed_in_frame_mobjects(plane_text_y)
+ self.wait()
+ self.play(ReplacementTransform(paraboloid_copy1, paraboloid_y))
+ self.play(FadeOut(plane2), FadeOut(plane_text_y))
+
+ line_y = Line(np.array([0,-3.5,0]), np.array([0,3.5,0]), color = GREEN_E)
+
+ self.play(ShowCreation(parabola_y_out), ShowCreation(line_y))
+
+ slope_text_y = TexMobject("Slope =", "{\\partial", "f", "\\over", "\\partial", "y}").scale(0.6).move_to(2*UP + 3.5*RIGHT)
+ slope_text_y[0].set_color(ORANGE)
+ slope_text_y.set_color_by_tex("\\partial",YELLOW_E)
+ slope_text_y.set_color_by_tex("f",PINK)
+ slope_text_y[5].set_color(GREEN_E)
+
+ self.add_fixed_in_frame_mobjects(slope_text_y)
+
+
+ dot_y = Dot().rotate(PI/2).set_color(GREEN_E)
+ alpha_y = ValueTracker(0)
+ vector_y = self.get_tangent_vector(alpha_y.get_value(),parabola_y_out,scale=1.5)
+ dot_y.add_updater(lambda m: m.move_to(vector_y.get_center()))
+ self.play(
+ ShowCreation(parabola_y_out),
+ GrowFromCenter(dot_y),
+ GrowArrow(vector_y)
+ )
+ vector_y.add_updater(
+ lambda m: m.become(
+ self.get_tangent_vector(alpha_y.get_value()%1,parabola_y_out,scale=1.5)
+ )
+ )
+ self.add(vector_y,dot_y)
+ self.play(alpha_y.increment_value, 1, run_time=10, rate_func=linear)
+
+ self.wait(2)
+ self.play(FadeOut(parabola_y_out), FadeOut(line_y), FadeOut(vector_y), FadeOut(dot_y), FadeOut(slope_text_y))
+
+ self.move_camera(phi=60* DEGREES,theta= 45*DEGREES)
+ self.play(ReplacementTransform(paraboloid_y, paraboloid_copy2))
+ self.wait()
+
+
+
+
+
+
+
+
+
+ def get_tangent_vector(self, proportion, curve, dx=0.001, scale=1):
+ coord_i = curve.point_from_proportion(proportion)
+ coord_f = curve.point_from_proportion(proportion + dx)
+ reference_line = Line(coord_i,coord_f)
+ unit_vector = reference_line.get_unit_vector() * scale
+ vector = Line(coord_i - unit_vector , coord_i + unit_vector, color = ORANGE, buff=0)
+ return vector
+
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/file6_clariant_rule.py b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/file6_clariant_rule.py
new file mode 100644
index 0000000..b79f77c
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/file6_clariant_rule.py
@@ -0,0 +1,64 @@
+from manimlib.imports import *
+
+class ClariantRule(Scene):
+ def construct(self):
+ derivatives = TextMobject(r"$cos(x)y^3$",r"$-sin(x)y^3$", r"$3cos(x)y^2$", r"$-cos(x)y^3$", r"$-3sin(x)y^2$", r"$-3sin(x)y^2$", r"$6cos(x)y$")
+
+ partial_derivatives = TextMobject(r"$\frac{\partial}{\partial x}$", r"$\frac{\partial}{\partial y}$")
+
+
+ derivatives[0].move_to(2*UP).set_color(PURPLE)
+ derivatives[1].move_to(3*LEFT).set_color(YELLOW_C)
+ derivatives[2].move_to(3*RIGHT).set_color(BLUE_C)
+
+ arrrow_1 = Arrow(derivatives[0].get_bottom(), derivatives[1].get_top())
+ arrrow_1_lab = partial_derivatives[0].copy().scale(0.7)
+ arrrow_1_lab.move_to(2.5*LEFT+ 1.3*UP)
+
+ arrrow_2 = Arrow(derivatives[0].get_bottom(), derivatives[2].get_top())
+ arrrow_2_lab = partial_derivatives[1].copy().scale(0.7)
+ arrrow_2_lab.move_to(2.5*RIGHT+ 1.3*UP)
+
+ self.play(Write(derivatives[0]))
+ self.play(GrowArrow(arrrow_1), GrowArrow(arrrow_2), Write(arrrow_1_lab), Write(arrrow_2_lab))
+
+ self.play(Write(derivatives[1]))
+ self.play(Write(derivatives[2]))
+
+ derivatives[3].move_to(2*DOWN + 4.5*LEFT).set_color(GREEN_C)
+ derivatives[4].move_to(2*DOWN + 1.5*LEFT).set_color(PINK)
+ derivatives[5].move_to(2*DOWN + 1.5*RIGHT).set_color(PINK)
+ derivatives[6].move_to(2*DOWN + 4.5*RIGHT).set_color(ORANGE)
+
+ arrrow_3 = Arrow(derivatives[1].get_bottom(), derivatives[3].get_top())
+ arrrow_3_lab = partial_derivatives[0].copy().scale(0.7)
+ arrrow_3_lab.move_to(4.3*LEFT+ 0.8*DOWN)
+
+ arrrow_4 = Arrow(derivatives[1].get_bottom(), derivatives[4].get_top())
+ arrrow_4_lab = partial_derivatives[1].copy().scale(0.7)
+ arrrow_4_lab.move_to(1.6*LEFT+ 0.8*DOWN)
+
+ arrrow_5 = Arrow(derivatives[2].get_bottom(), derivatives[5].get_top())
+ arrrow_5_lab = partial_derivatives[0].copy().scale(0.7)
+ arrrow_5_lab.move_to(1.6*RIGHT+ 0.8*DOWN)
+
+ arrrow_6 = Arrow(derivatives[2].get_bottom(), derivatives[6].get_top())
+ arrrow_6_lab = partial_derivatives[1].copy().scale(0.7)
+ arrrow_6_lab.move_to(4.3*RIGHT+ 0.8*DOWN)
+
+ self.play(GrowArrow(arrrow_3), GrowArrow(arrrow_4), Write(arrrow_3_lab), Write(arrrow_4_lab))
+ self.play(Write(derivatives[3]), Write(derivatives[4]))
+
+ self.play(GrowArrow(arrrow_5), GrowArrow(arrrow_6), Write(arrrow_5_lab), Write(arrrow_6_lab))
+ self.play(Write(derivatives[5]), Write(derivatives[6]))
+
+ brace1 = Brace(derivatives[4:6], DOWN, buff = SMALL_BUFF, color = RED_C)
+ brace_t1 = brace1.get_text("Mixed partial derivatives are the same!")
+ brace_t1.set_color(RED_C)
+
+ self.play(GrowFromCenter(brace1), FadeIn(brace_t1))
+
+ self.wait()
+
+
+
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/file7_partial_deriv_clariant_rule.py b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/file7_partial_deriv_clariant_rule.py
new file mode 100644
index 0000000..313c6cd
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/file7_partial_deriv_clariant_rule.py
@@ -0,0 +1,108 @@
+from manimlib.imports import *
+
+class ClariantRule(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes()
+
+ function = ParametricSurface(
+ lambda u, v: np.array([
+ 3.5*np.sin(u)*np.cos(v),
+ 3.5*np.sin(u)*np.sin(v),
+ 3.5*3.5*np.sin(u)*np.sin(u)*(1+2*np.sin(v)*np.sin(v))*np.exp(1 - 3.5*3.5*np.sin(u)*np.sin(u) )
+ ]),u_min=0,u_max=PI,v_min=0,v_max=2*PI, color = BLUE_C, fill_color = BLUE_C, fill_opacity = 0.1,
+ resolution=(15, 32)).scale(1)
+
+
+ function_copy1 = function.copy()
+ function_copy2 = function.copy()
+
+ func_x =ParametricFunction(
+ lambda u : np.array([
+ u,
+ -1,
+ (u*u )*np.exp(1-u*u)
+ ]),color=RED_E,t_min=-3.5,t_max=3.5,
+ )
+
+ func_y =ParametricFunction(
+ lambda u : np.array([
+ 0,
+ u,
+ (3*u*u)*np.exp(1-u*u)
+ ]),color=PINK,t_min=-3.5,t_max=3.5,
+ )
+
+ plane_x = Polygon(np.array([-3.5,-1,-3]),np.array([3.5,-1,-3]),np.array([3.5,-1,3]),np.array([-3.5,-1,3]),np.array([-3.5,-1,-3]), color = YELLOW_E, fill_color = YELLOW_B, fill_opacity = 0.1)
+ plane_text_x = TextMobject(r"$y = -1$", color = YELLOW_C).move_to(np.array([5,0,2.7])).scale(0.7)
+
+ plane_y = Polygon(np.array([0,-3.5,-3]),np.array([0,3.5,-3]),np.array([0,3.5,3]),np.array([0,-3.5,3]),np.array([0,-3.5,-3]), color = GREEN_E, fill_color = GREEN_B, fill_opacity = 0.1)
+ plane_text_y = TextMobject(r"$x = 0$", color = GREEN_C).move_to(np.array([0,4,2.7])).scale(0.7)
+
+ surface_eqn = TextMobject("Surface", r"$z = (x^2 + 3y^2)e^{(1 - x^2 - y^2)}$", color = YELLOW_C).scale(0.6).move_to(np.array([4.6*LEFT+3.5*UP]))
+ surface_eqn[0].set_color(BLUE_C)
+
+ self.set_camera_orientation(phi=60 * DEGREES, theta = 45*DEGREES)
+
+ self.add(axes)
+ axis = TextMobject(r"X",r"Y",r"Z")
+ axis[0].move_to(6*RIGHT)
+ axis[1].move_to(6*UP)
+ axis[2].move_to(np.array([0,0,3.7]))
+
+ self.add_fixed_orientation_mobjects(axis[2])
+ self.add_fixed_orientation_mobjects(axis[0])
+ self.add_fixed_orientation_mobjects(axis[1])
+
+ self.play(ShowCreation(function))
+
+ self.add_fixed_in_frame_mobjects(surface_eqn)
+
+ self.play(ShowCreation(plane_x), ShowCreation(plane_y))
+ self.add_fixed_orientation_mobjects(plane_text_x, plane_text_y)
+
+ self.play(ShowCreation(func_x), ShowCreation(func_y))
+
+ dot_x = Dot().rotate(PI/2).set_color(YELLOW_E)
+ alpha_x = ValueTracker(0)
+ vector_x = self.get_tangent_vector(alpha_x.get_value(),func_x,scale=1.5)
+ dot_x.add_updater(lambda m: m.move_to(vector_x.get_center()))
+ self.play(
+ ShowCreation(func_x),
+ GrowFromCenter(dot_x),
+ GrowArrow(vector_x)
+ )
+ vector_x.add_updater(
+ lambda m: m.become(
+ self.get_tangent_vector(alpha_x.get_value()%1,func_x,scale=1.5)
+ )
+ )
+ dot_y = Dot().rotate(PI/2).set_color(GREEN_E)
+ alpha_y = ValueTracker(0)
+ vector_y = self.get_tangent_vector(alpha_y.get_value(),func_y,scale=1.5)
+ dot_y.add_updater(lambda m: m.move_to(vector_y.get_center()))
+ self.play(
+ ShowCreation(func_y),
+ GrowFromCenter(dot_y),
+ GrowArrow(vector_y)
+ )
+ vector_y.add_updater(
+ lambda m: m.become(
+ self.get_tangent_vector(alpha_y.get_value()%1,func_y,scale=1.5)
+ )
+ )
+ self.add(vector_x,dot_x)
+
+ self.play(alpha_x.increment_value, 1, run_time=10, rate_func=linear)
+
+ self.add(vector_y,dot_y)
+ self.play(alpha_y.increment_value, 1, run_time=10, rate_func=linear)
+
+ self.wait(2)
+
+
+
+
+
+
+
+
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/file8_chain_rule.py b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/file8_chain_rule.py
new file mode 100644
index 0000000..f50d2d1
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/file8_chain_rule.py
@@ -0,0 +1,60 @@
+from manimlib.imports import *
+
+class ChainRule(Scene):
+ def construct(self):
+
+ chain_rule = TextMobject(r"$\frac{dw}{dt}$", r"=", r"$\frac{\partial w}{\partial x}$", r"$\frac{dx}{dt}$", r"+", r"$\frac{\partial w}{\partial y}$", r"$\frac{dy}{dt}$").move_to(4*RIGHT).scale(0.8)
+
+ chain_rule[0].set_color(ORANGE)
+ chain_rule[2].set_color(GREEN_C)
+ chain_rule[3].set_color(RED_C)
+ chain_rule[5].set_color(YELLOW_C)
+ chain_rule[6].set_color(BLUE_C)
+
+ functions = TextMobject(r"$w =f(x,y)$",r"$x$", r"$y$", r"$t$")
+
+ functions[0].move_to(3.3*UP+1*LEFT).set_color(ORANGE)
+ functions[1].move_to(3.3*LEFT).set_color(PURPLE)
+ functions[2].move_to(1.3*RIGHT).set_color(PURPLE)
+ functions[3].move_to(3.3*DOWN+1*LEFT).set_color(WHITE)
+
+ partial_derivatives = TextMobject(r"$\frac{\partial w}{\partial x}$", r"$\frac{\partial w}{\partial y}$")
+
+ partial_derivatives[0].move_to(1.5*UP+3*LEFT).set_color(GREEN_C)
+ partial_derivatives[1].move_to(1.5*UP+1*RIGHT).set_color(YELLOW_C)
+
+ derivatives = TextMobject(r"$\frac{dx}{dt}$", r"$\frac{dy}{dt}$")
+
+ derivatives[0].move_to(1.5*DOWN+3*LEFT).set_color(RED_C)
+ derivatives[1].move_to(1.5*DOWN+1*RIGHT).set_color(BLUE_C)
+
+ line_f_x = Line(np.array([-1,3,0]), np.array([-3,0,0]), color = BLUE_C)
+ line_f_y = Line(np.array([-1,3,0]), np.array([1,0,0]), color = BLUE_C)
+ line_x_t = Line(np.array([-3,0,0]), np.array([-1,-3,0]), color = BLUE_C)
+ line_y_t = Line(np.array([1,0,0]), np.array([-1,-3,0]), color = BLUE_C)
+
+ dot_f = Dot().shift(np.array([-1,3,0])).set_color(BLUE_C)
+ dot_x = Dot().shift(np.array([-3,0,0])).set_color(BLUE_C)
+ dot_y = Dot().shift(np.array([1,0,0])).set_color(BLUE_C)
+ dot_t = Dot().shift(np.array([-1,-3,0])).set_color(BLUE_C)
+
+ variables = TextMobject("Dependent Variable","Intermediate Variables", "Dependent Variable").set_color_by_gradient(RED, ORANGE, YELLOW, GREEN, BLUE, PURPLE).scale(0.7)
+ variables[0].move_to(3.3*UP+3.5*RIGHT)
+ variables[1].move_to(3.5*RIGHT)
+ variables[2].move_to(3.3*DOWN+3.5*RIGHT)
+
+ self.play(ShowCreation(dot_f), Write(functions[0]))
+ self.play(ShowCreation(dot_x), ShowCreation(line_f_x), Write(functions[1]), ShowCreation(dot_y), ShowCreation(line_f_y), Write(functions[2]))
+ self.play(Write(partial_derivatives[0]), Write(partial_derivatives[1]))
+ self.wait()
+
+ self.play(ShowCreation(dot_t), ShowCreation(line_x_t), ShowCreation(line_y_t), Write(functions[3]))
+ self.play(Write(derivatives[0]), Write(derivatives[1]))
+ self.wait()
+
+ self.play(Write(variables[0]), Write(variables[1]), Write(variables[2]))
+
+ self.play(FadeOut(variables))
+ self.play(Write(chain_rule))
+ self.wait()
+ \ No newline at end of file
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file1_partial_deriv_gas_law.gif b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file1_partial_deriv_gas_law.gif
new file mode 100644
index 0000000..8fdb80f
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file1_partial_deriv_gas_law.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file2_partial_deriv_hill.gif b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file2_partial_deriv_hill.gif
new file mode 100644
index 0000000..3c758ff
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file2_partial_deriv_hill.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file3_partial_deriv_defn.gif b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file3_partial_deriv_defn.gif
new file mode 100644
index 0000000..c66b3fa
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file3_partial_deriv_defn.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file4_partial_deriv_example.gif b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file4_partial_deriv_example.gif
new file mode 100644
index 0000000..d2bf541
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file4_partial_deriv_example.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file5_partial_deriv_func_2maximas.gif b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file5_partial_deriv_func_2maximas.gif
new file mode 100644
index 0000000..db7f4f8
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file5_partial_deriv_func_2maximas.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file6_clariant_rule.gif b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file6_clariant_rule.gif
new file mode 100644
index 0000000..8377827
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file6_clariant_rule.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file7_partial_deriv_clariant_rule.gif b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file7_partial_deriv_clariant_rule.gif
new file mode 100644
index 0000000..32d5e92
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file7_partial_deriv_clariant_rule.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file8_chain_rule.gif b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file8_chain_rule.gif
new file mode 100644
index 0000000..596b08d
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/partial-derivatives/gifs/file8_chain_rule.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/README.md b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/README.md
new file mode 100644
index 0000000..4339c30
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/README.md
@@ -0,0 +1,20 @@
+**file1_scalar_function**
+![file1_scalar_function](https://github.com/nishanpoojary/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/gifs/file1_scalar_functions.gif)
+
+**file2_domain_range**
+![file2_domain_range](https://github.com/nishanpoojary/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/gifs/file2_domain_range.gif)
+
+**file3_parabola_example**
+![file3_parabola_example](https://github.com/nishanpoojary/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/gifs/file3_parabola_example.gif)
+
+**file4_level_curves**
+![file4_non_rect_region](https://github.com/nishanpoojary/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/gifs/file4_level_curves.gif)
+
+**file5_level_surface**
+![file5_level_surface](https://github.com/nishanpoojary/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/gifs/file5_level_surface.gif)
+
+**file6_scalar_function_application**
+![file6_scalar_function_application](https://github.com/nishanpoojary/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/gifs/file6_scalar_function_application.gif)
+
+**file7_neural_nets**
+![file7_neural_nets](https://github.com/nishanpoojary/FSF-mathematics-python-code-archive/blob/master/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/gifs/file7_neural_nets.gif)
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/Scalar_Function_Quiz.pdf b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/Scalar_Function_Quiz.pdf
new file mode 100644
index 0000000..6d94a2c
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/Scalar_Function_Quiz.pdf
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/file1_scalar_functions.py b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/file1_scalar_functions.py
new file mode 100644
index 0000000..1a6f4ed
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/file1_scalar_functions.py
@@ -0,0 +1,50 @@
+from manimlib.imports import *
+
+class ScalarFunction(Scene):
+ def construct(self):
+ circle = Circle(radius = 1.5, color = BLUE_E, fill_color = BLUE_C, fill_opacity = 0.1).move_to(2*LEFT)
+ dot_circle = Dot().shift(np.array([-1.5,0,0])).set_color(BLUE_E)
+ dot_circle_lab = TextMobject(r"$a$", color = BLUE_E).next_to(dot_circle, DOWN)
+
+ arrow = Arrow(np.array([3,-3,0]),np.array([3,3,0]))
+ line = Line(np.array([3,-1.5,0]),np.array([3,1.5,0]), color = RED_C)
+
+ dot0 = Dot().shift(np.array([3,0,0])).set_color(RED_E)
+ dot0_lab = TextMobject(r"$f(a)$", color = RED_E).scale(0.8).next_to(dot0, RIGHT)
+
+ dot1 = Dot().shift(np.array([3,-1.5,0])).set_color(RED_C)
+
+ dot2 = Dot().shift(np.array([3,1.5,0])).set_color(RED_C)
+ dot2_lab = TextMobject(r"$f(A)$", color = RED_C).scale(0.8).next_to(dot2, RIGHT)
+
+ arrow_f = Arrow(np.array([-1.5,0,0]),np.array([3,0,0]), color = YELLOW_C, buff = 0.1)
+
+ R = TextMobject(r"$\mathbb{R}$", color = WHITE).move_to(np.array([3,-3.3,0]))
+
+ A = TextMobject(r"$A$", color = BLUE_E).move_to(np.array([-2.5,-3.3,0]))
+
+ F = TextMobject(r"$f$", color = GREY).move_to(np.array([0,-2.9,0]))
+
+ F_center = TextMobject(r"$f$", color = YELLOW_C).move_to(np.array([0.8,0.5,0]))
+
+ arrow_R_A = Arrow(np.array([-2.3,-3.3,0]),np.array([2.7,-3.3,0]), color = GREY, buff = 0.1)
+
+ scalar_function = TextMobject(r"Scalar Valued Function", r"$f: A \rightarrow \mathbb{R}$", color = PURPLE).move_to(np.array([0,3.5,0]))
+ scalar_function[1].set_color(GREEN_C)
+
+
+
+ self.play(ShowCreation(circle))
+ self.play(ShowCreation(arrow))
+
+
+ self.play(ShowCreation(dot1), ShowCreation(dot2))
+ self.play(ShowCreation(dot_circle))
+ self.play(ShowCreation(dot_circle_lab), ShowCreation(dot2_lab))
+ self.play(ShowCreation(A), ShowCreation(R))
+ self.play(GrowArrow(arrow_f), ShowCreation(dot0), ShowCreation(dot0_lab), ShowCreation(F_center), GrowArrow(arrow_R_A), ShowCreation(F), Transform(circle.copy(), line.copy()))
+
+ self.play(Write(scalar_function))
+
+
+ self.wait(2) \ No newline at end of file
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/file2_domain_range.py b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/file2_domain_range.py
new file mode 100644
index 0000000..1b54cb6
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/file2_domain_range.py
@@ -0,0 +1,190 @@
+# Plotting Graphs
+from manimlib.imports import *
+
+class PlotGraphs(GraphScene):
+ CONFIG = {
+ "x_min": -5,
+ "x_max": 5,
+ "y_min": 0,
+ "y_max": 4,
+ "graph_origin": ORIGIN + 2.5* DOWN,
+ "x_labeled_nums": list(range(-5, 6)),
+ "y_labeled_nums": list(range(0, 5)),
+ }
+ def construct(self):
+
+ topic = TextMobject("Domain and Range")
+ topic.scale(2)
+ topic.set_color(YELLOW)
+ self.play(Write(topic))
+ self.play(FadeOut(topic))
+ self.wait(1)
+
+ scalar_func_R = TextMobject(r"Scalar Valued Functions in $R$").scale(1.5).set_color_by_gradient(RED, ORANGE, YELLOW, GREEN, BLUE, PURPLE)
+ self.play(Write(scalar_func_R))
+ self.play(FadeOut(scalar_func_R))
+ self.wait(1)
+
+
+ XTD = self.x_axis_width/(self.x_max- self.x_min)
+ YTD = self.y_axis_height/(self.y_max- self.y_min)
+
+ self.setup_axes(animate = True)
+
+ graphobj = self.get_graph(lambda x : np.sqrt(x + 4), x_min = -4, x_max = 5)
+ graph_lab = self.get_graph_label(graphobj, label = r"\sqrt{x + 4}")
+
+
+ rangeline1 = Arrow(self.graph_origin+2.2*YTD*UP+5*XTD*LEFT, self.graph_origin+4.1*YTD*UP+5*XTD*LEFT)
+ rangeline2 = Arrow(self.graph_origin+1.7*YTD*UP+5*XTD*LEFT, self.graph_origin+5*XTD*LEFT)
+ rangeline1.set_color(RED)
+ rangeline2.set_color(RED)
+
+ rangeMsg = TextMobject(r"Range: $y \geq 0$")
+ rangeMsg.move_to(self.graph_origin+2*YTD*UP+5*XTD*LEFT)
+ rangeMsg.scale(0.5)
+ rangeMsg.set_color(YELLOW)
+
+ domainline1 = Arrow(self.graph_origin+0.6*YTD*DOWN+1.2*XTD*LEFT, self.graph_origin+0.6*YTD*DOWN + 4*XTD*LEFT, buff = 0.1)
+ domainline2 = Arrow(self.graph_origin+0.6*YTD*DOWN+1.1*XTD*RIGHT, self.graph_origin+0.6*YTD*DOWN + 5.3*XTD*RIGHT, buff = 0.1)
+ domainline1.set_color(PINK)
+ domainline2.set_color(PINK)
+
+ domainMsg = TextMobject(r"Domain: $x \geq -4$")
+ domainMsg.move_to(self.graph_origin+0.6*YTD*DOWN)
+ domainMsg.scale(0.5)
+ domainMsg.set_color(GREEN)
+
+
+
+
+ self.play(ShowCreation(graphobj))
+ self.play(ShowCreation(graph_lab))
+ self.wait(1)
+ self.play(GrowArrow(rangeline1))
+ self.play(GrowArrow(rangeline2))
+ self.play(Write(rangeMsg))
+ self.wait(1)
+ self.play(GrowArrow(domainline1))
+ self.play(GrowArrow(domainline2))
+ self.play(Write(domainMsg))
+ self.wait(3)
+
+ self.wait(2)
+
+
+
+
+class PlotSineGraphs(GraphScene):
+ CONFIG = {
+ "x_min": -8,
+ "x_max": 8,
+ "y_min": -1,
+ "y_max": 1,
+ "graph_origin": ORIGIN,
+ "x_labeled_nums": list(range(-8, 9)),
+ "y_labeled_nums": list(range(-1, 2)),
+ }
+ def construct(self):
+
+
+
+ XTD = self.x_axis_width/(self.x_max- self.x_min)
+ YTD = self.y_axis_height/(self.y_max- self.y_min)
+
+ self.setup_axes(animate = True)
+
+ sineobj = self.get_graph(lambda x : np.sin(x), x_min = -7, x_max = 8)
+ sine_lab = self.get_graph_label(sineobj, label = "\\sin(x)")
+
+
+ rangeline1 = Line(8*XTD*LEFT,1*YTD*UP+8*XTD*LEFT)
+ rangeline2 = Line(8*XTD*LEFT,1*YTD*DOWN+8*XTD*LEFT)
+ rangeline1.set_color(RED)
+ rangeline2.set_color(RED)
+
+ rangeMsg = TextMobject(r"Range: $-1 \leq y \leq 1$")
+ rangeMsg.move_to(1.1*YTD*UP+8.5*XTD*LEFT)
+ rangeMsg.scale(0.5)
+ rangeMsg.set_color(YELLOW)
+
+
+ domainline1 = Arrow(1.1*YTD*DOWN+2*XTD*LEFT, 1.1*YTD*DOWN + 8.5*XTD*LEFT)
+ domainline2 = Arrow(1.1*YTD*DOWN+2*XTD*RIGHT, 1.1*YTD*DOWN + 8.5*XTD*RIGHT)
+ domainline1.set_color(PINK)
+ domainline2.set_color(PINK)
+
+ domainMsg = TextMobject(r"Domain: $[-\infty, \infty]$")
+ domainMsg.move_to(1.1*YTD*DOWN)
+ domainMsg.scale(0.5)
+ domainMsg.set_color(GREEN)
+
+
+
+ self.play(ShowCreation(sineobj))
+ self.play(ShowCreation(sine_lab))
+ self.wait(1)
+ self.play(GrowArrow(rangeline1))
+ self.play(GrowArrow(rangeline2))
+ self.play(Write(rangeMsg))
+ self.wait(1)
+ self.play(GrowArrow(domainline1))
+ self.play(GrowArrow(domainline2))
+ self.play(Write(domainMsg))
+ self.wait(3)
+
+
+
+
+class Paraboloid(ThreeDScene):
+ def construct(self):
+
+ scalar_func_R2 = TextMobject(r"Scalar Valued Functions in $R^2$").scale(1.5).set_color_by_gradient(RED, ORANGE, YELLOW, GREEN, BLUE, PURPLE)
+ self.play(Write(scalar_func_R2))
+ self.play(FadeOut(scalar_func_R2))
+ self.wait(1)
+
+ axes = ThreeDAxes()
+
+ paraboloid = ParametricSurface(
+ lambda u, v: np.array([
+ 2*np.sin(u)*np.cos(v),
+ 2*np.sin(u)*np.sin(v),
+ 2*2*np.sin(u)*np.sin(u)
+ ]),u_min=0,u_max=PI/2,v_min=0,v_max=2*PI,checkerboard_colors=[GREEN_C, GREEN_E],
+ resolution=(15, 32)).scale(1)
+
+ domain = Polygon(np.array([-5,-5,0]),np.array([5,-5,0]),np.array([5,5,0]),np.array([-5,5,0]),np.array([-5,-5,0]), color = BLUE_C, fill_color = BLUE_C, fill_opacity = 0.2)
+ domain_lab = TextMobject(r"$Domain: R^2$", color = YELLOW_C).scale(0.7).move_to(1*DOWN + 2*LEFT)
+
+ rangef = Line(np.array([0, 0,0]), np.array([0, 0,5]), color = RED_C)
+ rangef_lab = TextMobject(r"$Range: z \geq 0$", color = RED_C).scale(0.7).move_to(2*UP + 1.5*RIGHT)
+
+ func = TextMobject(r"$z = f(x,y) = x^2+y^2$").scale(0.7).move_to(3*UP + 4*LEFT).set_color_by_gradient(RED, ORANGE, YELLOW, GREEN, BLUE, PURPLE)
+
+ self.set_camera_orientation(phi=60 * DEGREES, theta = 0*DEGREES)
+ self.begin_ambient_camera_rotation(rate=0.3)
+
+ self.add(axes)
+
+ axis = TextMobject(r"X",r"Y",r"Z")
+ axis[0].move_to(6*RIGHT)
+ axis[1].move_to(6*UP)
+ axis[2].move_to(np.array([0,0,3.7]))
+
+ self.add_fixed_orientation_mobjects(axis[2])
+ self.add_fixed_orientation_mobjects(axis[0])
+ self.add_fixed_orientation_mobjects(axis[1])
+
+
+
+ self.add_fixed_in_frame_mobjects(func)
+ self.play(Write(paraboloid))
+ self.play(ShowCreation(domain))
+ self.add_fixed_in_frame_mobjects(domain_lab)
+ self.wait()
+ self.play(ShowCreation(rangef))
+ self.add_fixed_in_frame_mobjects(rangef_lab)
+ self.wait(5)
+
+ \ No newline at end of file
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/file3_parabola_example.py b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/file3_parabola_example.py
new file mode 100644
index 0000000..63c16b3
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/file3_parabola_example.py
@@ -0,0 +1,47 @@
+from manimlib.imports import *
+
+class Parabola(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes() # creates a 3D Axis
+
+ paraboloid = ParametricSurface(
+ lambda u, v: np.array([
+ 2*np.cosh(u)*np.cos(v),
+ 2*np.cosh(u)*np.sin(v),
+ 2*np.sinh(u)
+ ]),v_min=0,v_max=TAU,u_min=0,u_max=2,checkerboard_colors=[YELLOW_D, YELLOW_E],#
+ resolution=(15, 32))
+
+ text3d = TextMobject(r"Plot of $f: \mathbb{R}^2 \rightarrow \mathbb{R}$", r"$z = f(x,y) = \sqrt{x^2 + y^2 - 4}$")
+ text3d[0].move_to(4*LEFT+2*DOWN)
+ text3d[1].next_to(text3d[0], DOWN)
+ text3d[0].set_color_by_gradient(RED, ORANGE, YELLOW, GREEN, BLUE, PURPLE)
+ text3d[1].set_color_by_gradient(RED, ORANGE, YELLOW, GREEN, BLUE)
+
+ #self.set_camera_orientation(phi=0 * DEGREES,theta=270*DEGREES)
+ self.move_camera(phi=110* DEGREES,theta=45*DEGREES)
+
+ self.add(axes)
+
+ axis = TextMobject(r"X",r"Y",r"Z")
+ axis[0].move_to(6*RIGHT)
+ axis[1].move_to(6*UP)
+ axis[2].move_to(np.array([0,0,3.7]))
+
+ self.add_fixed_orientation_mobjects(axis[2])
+ self.add_fixed_orientation_mobjects(axis[0])
+ self.add_fixed_orientation_mobjects(axis[1])
+
+
+ self.play(ShowCreation(paraboloid))
+ self.add_fixed_in_frame_mobjects(text3d)
+ self.play(Write(text3d[0]))
+ self.play(Write(text3d[1]))
+ self.begin_ambient_camera_rotation(rate=0.2)
+ self.wait(3)
+ self.move_camera(phi=0 * DEGREES,theta=180*DEGREES,run_time=3)
+ self.wait(3)
+ self.move_camera(phi=110* DEGREES,theta=90*DEGREES,run_time=3)
+ self.wait(3)
+
+ \ No newline at end of file
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/file4_level_curves.py b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/file4_level_curves.py
new file mode 100644
index 0000000..2b6f719
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/file4_level_curves.py
@@ -0,0 +1,118 @@
+from manimlib.imports import *
+
+class LevelCurves(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes()
+
+ paraboloid = ParametricSurface(
+ lambda u, v: np.array([
+ u*np.cos(v),
+ u*np.sin(v),
+ -u*u+2
+ ]),u_min=-1.414,u_max=1.414,v_min=0,v_max=2*PI, color = BLUE_C, fill_color = BLUE_C, fill_opacity = 0.1,
+ resolution=(15, 32)).scale(1)
+
+ plane_0 = Polygon(np.array([2,-2,0]),np.array([2,2,0]),np.array([-2,2,0]),np.array([-2,-2,0]),np.array([2,-2,0]), color = BLUE_E, fill_color = BLUE_E, fill_opacity = 0.3)
+ plane_0_lab = TextMobject("C = 0").move_to(0.4*UP+3.2*RIGHT).set_color(BLUE_E).scale(0.6)
+ circle_0 = Circle(radius = 1.414 , color = BLUE_E)
+ circle_0_lab = TextMobject("0").move_to(1.1*DOWN+1.1*RIGHT).set_color(BLUE_E).scale(0.6)
+
+ plane_0_5 = Polygon(np.array([2,-2,0.5]),np.array([2,2,0.5]),np.array([-2,2,0.5]),np.array([-2,-2,0.5]),np.array([2,-2,0.5]), color = GREEN_C, fill_color = GREEN_C, fill_opacity = 0.3)
+ plane_0_5_lab = TextMobject("C = 0.5").move_to(0.8*UP+3.4*RIGHT).set_color(GREEN_C).scale(0.6)
+ circle_0_5 = Circle(radius = 1.224 , color = GREEN_C)
+ circle_0_5_lab = TextMobject("0.5").move_to(0.9*DOWN+0.9*RIGHT).set_color(GREEN_C).scale(0.6)
+ circle_0_5_copy = circle_0_5.copy().move_to(np.array([0,0,0.5]))
+
+ plane_1 = Polygon(np.array([2,-2,1]),np.array([2,2,1]),np.array([-2,2,1]),np.array([-2,-2,1]),np.array([2,-2,1]), color = YELLOW_C, fill_color = YELLOW_C, fill_opacity = 0.3)
+ plane_1_lab = TextMobject("C = 1").move_to(1.2*UP+3.3*RIGHT).set_color(YELLOW_C).scale(0.6)
+ circle_1 = Circle(radius = 1 , color = YELLOW_C)
+ circle_1_lab = TextMobject("1").move_to(0.7*DOWN+0.7*RIGHT).set_color(YELLOW_C).scale(0.6)
+ circle_1_copy = circle_1.copy().move_to(np.array([0,0,1]))
+
+ plane_1_5 = Polygon(np.array([2,-2,1.5]),np.array([2,2,1.5]),np.array([-2,2,1.5]),np.array([-2,-2,1.5]),np.array([2,-2,1.5]), color = ORANGE, fill_color = ORANGE, fill_opacity = 0.3)
+ plane_1_5_lab = TextMobject("C = 1.5").move_to(1.7*UP+3.4*RIGHT).set_color(ORANGE).scale(0.6)
+ circle_1_5 = Circle(radius = 0.707 , color = ORANGE)
+ circle_1_5_lab = TextMobject("1.5").move_to(0.5*DOWN+0.5*RIGHT).set_color(ORANGE).scale(0.6)
+ circle_1_5_copy = circle_1_5.copy().move_to(np.array([0,0,1.5]))
+
+ plane_2 = Polygon(np.array([2,-2,2]),np.array([2,2,2]),np.array([-2,2,2]),np.array([-2,-2,2]),np.array([2,-2,2]), color = RED_C, fill_color = RED_C, fill_opacity = 0.3)
+ plane_2_lab = TextMobject("C = 2").move_to(2.1*UP+3.3*RIGHT).set_color(RED_C).scale(0.6)
+ dot_2 = Dot().set_fill(RED_C)
+ circle_2_lab = TextMobject("2").move_to(0.2*DOWN+0.2*RIGHT).set_color(RED_C).scale(0.6)
+ dot_2_copy = dot_2.copy().move_to(np.array([0,0,2]))
+
+ level_curves_line1 = DashedLine(np.array([0,-1.414,0]),np.array([0,-2,1]), color = WHITE)
+ level_curves_line2 = DashedLine(np.array([0,-1.224,0.5]),np.array([0,-2,1]), color = WHITE)
+ level_curves_line3 = DashedLine(np.array([0,-1,1]),np.array([0,-2,1]), color = WHITE)
+ level_curves_line4 = DashedLine(np.array([0,-0.707,1.5]),np.array([0,-2,1]), color = WHITE)
+ level_curves_line5 = DashedLine(np.array([0,0,2]),np.array([0,-2,1]), color = WHITE)
+
+ level_curves = TextMobject("Level Curves").move_to(1.4*UP+3*LEFT).set_color_by_gradient(RED, ORANGE, YELLOW, GREEN, BLUE, PURPLE).scale(0.8)
+
+
+ contour_line1 = DashedLine(np.array([0,-1.414,0]),np.array([0,-2,1]), color = WHITE)
+ contour_line2 = DashedLine(np.array([0,-1.224,0]),np.array([0,-2,1]), color = WHITE)
+ contour_line3 = DashedLine(np.array([0,-1,0]),np.array([0,-2,1]), color = WHITE)
+ contour_line4 = DashedLine(np.array([0,-0.707,0]),np.array([0,-2,1]), color = WHITE)
+ contour_line5 = DashedLine(np.array([0,0,0]),np.array([0,-2,1]), color = WHITE)
+
+ contours = TextMobject("Contours").move_to(1.4*UP+2.7*LEFT).set_color_by_gradient(RED, ORANGE, YELLOW, GREEN, BLUE, PURPLE).scale(0.8)
+
+
+ topic = TextMobject("Contour Plot").move_to(3*UP+3*LEFT).set_color_by_gradient(RED, ORANGE, YELLOW, GREEN, BLUE, PURPLE).scale(0.8)
+
+ self.set_camera_orientation(phi=80 * DEGREES, theta = 0*DEGREES)
+ #self.set_camera_orientation(phi=0 * DEGREES, theta = 0*DEGREES)
+
+ self.add(axes)
+
+ axis = TextMobject(r"X",r"Y",r"Z")
+ axis[0].move_to(6*RIGHT)
+ axis[1].move_to(6*UP)
+ axis[2].move_to(np.array([0,0,3.7]))
+
+ self.add_fixed_orientation_mobjects(axis[2])
+ self.add_fixed_orientation_mobjects(axis[0])
+ self.add_fixed_orientation_mobjects(axis[1])
+
+ self.play(Write(paraboloid))
+ self.wait()
+ self.play(ShowCreation(plane_0), ShowCreation(circle_0))
+ self.add_fixed_in_frame_mobjects(plane_0_lab)
+ self.wait()
+ self.play(ShowCreation(plane_0_5), ShowCreation(circle_0_5_copy), ShowCreation(circle_0_5))
+ self.add_fixed_in_frame_mobjects(plane_0_5_lab)
+ self.wait()
+ self.play(ShowCreation(plane_1), ShowCreation(circle_1_copy), ShowCreation(circle_1))
+ self.add_fixed_in_frame_mobjects(plane_1_lab)
+ self.wait()
+ self.play(ShowCreation(plane_1_5), ShowCreation(circle_1_5_copy), ShowCreation(circle_1_5))
+ self.add_fixed_in_frame_mobjects(plane_1_5_lab)
+ self.wait()
+ self.play(ShowCreation(plane_2), ShowCreation(dot_2_copy), ShowCreation(dot_2))
+ self.add_fixed_in_frame_mobjects(plane_2_lab)
+ self.wait()
+
+ self.move_camera(phi=60 * DEGREES, theta = 30*DEGREES,run_time=3)
+ self.play(FadeOut(plane_0), FadeOut(plane_0_lab), FadeOut(plane_0_5), FadeOut(plane_0_5_lab), FadeOut(plane_1), FadeOut(plane_1_lab), FadeOut(plane_1_5), FadeOut(plane_1_5_lab), FadeOut(plane_2), FadeOut(plane_2_lab))
+
+ self.play(GrowArrow(level_curves_line1), GrowArrow(level_curves_line2), GrowArrow(level_curves_line3), GrowArrow(level_curves_line4), GrowArrow(level_curves_line5))
+ self.add_fixed_in_frame_mobjects(level_curves)
+ self.wait()
+ self.play(FadeOut(level_curves_line1), FadeOut(level_curves_line2), FadeOut(level_curves_line3), FadeOut(level_curves_line4), FadeOut(level_curves_line5), FadeOut(level_curves))
+ self.play(FadeOut(circle_0_5_copy), FadeOut(circle_1_copy), FadeOut(circle_1_5_copy), FadeOut(dot_2_copy))
+ self.wait()
+
+ self.play(GrowArrow(contour_line1), GrowArrow(contour_line2), GrowArrow(contour_line3), GrowArrow(contour_line4), GrowArrow(contour_line5))
+ self.add_fixed_in_frame_mobjects(contours)
+ self.wait()
+ self.play(FadeOut(contour_line1), FadeOut(contour_line2), FadeOut(contour_line3), FadeOut(contour_line4), FadeOut(contour_line5), FadeOut(contours))
+
+
+ self.move_camera(phi=0 * DEGREES, theta = 0*DEGREES,run_time=3)
+ self.play(FadeOut(paraboloid))
+ self.wait()
+
+ self.add_fixed_in_frame_mobjects(circle_0_lab, circle_0_5_lab, circle_1_lab, circle_1_5_lab,circle_2_lab)
+ self.add_fixed_in_frame_mobjects(topic)
+ self.wait(3) \ No newline at end of file
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/file5_level_surface.py b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/file5_level_surface.py
new file mode 100644
index 0000000..8052676
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/file5_level_surface.py
@@ -0,0 +1,78 @@
+from manimlib.imports import *
+
+class LevelSurface(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes()
+
+ surface_0 = ParametricSurface(
+ lambda u, v: np.array([
+ u*np.cos(v),
+ u*np.sin(v),
+ (u*u*np.cos(v)*np.cos(v))-(u*np.sin(v)/5)+0
+ ]),u_min=-1,u_max=1,v_min=0,v_max=2*PI,checkerboard_colors=[RED_C, RED_E],
+ resolution=(15, 32)).scale(1)
+
+ k_0 = TextMobject("K = 0", color = RED_C).scale(0.7)
+
+ surface_1 = ParametricSurface(
+ lambda u, v: np.array([
+ u*np.cos(v),
+ u*np.sin(v),
+ (u*u*np.cos(v)*np.cos(v))-(u*np.sin(v)/5)+1
+ ]),u_min=-1,u_max=1,v_min=0,v_max=2*PI,checkerboard_colors=[GREEN_C, GREEN_E],
+ resolution=(15, 32)).scale(1)
+
+ k_1 = TextMobject("K = 1", color = GREEN_C).scale(0.7)
+
+ surface_2 = ParametricSurface(
+ lambda u, v: np.array([
+ u*np.cos(v),
+ u*np.sin(v),
+ (u*u*np.cos(v)*np.cos(v))-(u*np.sin(v)/5)+2
+ ]),u_min=-1,u_max=1,v_min=0,v_max=2*PI,checkerboard_colors=[YELLOW_C, YELLOW_E],
+ resolution=(15, 32)).scale(1)
+
+ k_2 = TextMobject("K = 2", color = YELLOW_C).scale(0.7)
+
+ func = TextMobject(r"$w = g(x,y,z)$", r"$= z - f(x,y)$", r"$z-x^2+y/5 = K$")
+ func.set_color_by_gradient(RED, ORANGE, YELLOW, GREEN, BLUE, PURPLE)
+
+ self.set_camera_orientation(phi=90 * DEGREES, theta = 90*DEGREES)
+ self.begin_ambient_camera_rotation(rate=0.3)
+
+
+ self.add(axes)
+
+ axis = TextMobject(r"X",r"Y",r"Z")
+ axis[0].move_to(6*RIGHT)
+ axis[1].move_to(6*UP)
+ axis[2].move_to(3.7*UP)
+
+ self.add_fixed_in_frame_mobjects(axis[2])
+ self.add_fixed_orientation_mobjects(axis[0])
+ self.add_fixed_orientation_mobjects(axis[1])
+
+ self.play(Write(surface_0))
+ self.add_fixed_in_frame_mobjects(k_0)
+ k_0.move_to(np.array([1.4*RIGHT ]))
+
+ self.play(Write(surface_1))
+ self.add_fixed_in_frame_mobjects(k_1)
+ k_1.move_to(np.array([1.4*RIGHT + 1*UP]))
+
+ self.play(Write(surface_2))
+ self.add_fixed_in_frame_mobjects(k_2)
+ k_2.move_to(np.array([1.4*RIGHT + 2*UP]))
+ self.wait()
+
+ self.add_fixed_in_frame_mobjects(func)
+ func[0].move_to(np.array([4.5*LEFT + 3*UP]))
+ func[1].move_to(np.array([4.5*LEFT + 2.5*UP]))
+ func[2].move_to(np.array([4.5*LEFT + 2*UP]))
+
+ self.wait(3)
+ self.move_camera(phi=60 * DEGREES,run_time=3)
+ self.wait(2)
+
+
+ \ No newline at end of file
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/file6_scalar_function_application.py b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/file6_scalar_function_application.py
new file mode 100644
index 0000000..3ccfad6
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/file6_scalar_function_application.py
@@ -0,0 +1,140 @@
+from manimlib.imports import *
+
+class ScalarApplication(ThreeDScene):
+ def construct(self):
+ axes = ThreeDAxes() # creates a 3D Axis
+
+ self.add(axes)
+
+ axis = TextMobject(r"X",r"Y",r"Z")
+ axis[0].move_to(6*RIGHT)
+ axis[1].move_to(6*UP)
+ axis[2].move_to(np.array([0,0,3.7]))
+
+ self.add_fixed_orientation_mobjects(axis[2])
+ self.add_fixed_orientation_mobjects(axis[0])
+ self.add_fixed_orientation_mobjects(axis[1])
+
+ cube = Cube()
+ cube.set_fill(YELLOW_C, opacity = 0.2)
+ cube.scale(2)
+ self.set_camera_orientation(phi=0 * DEGREES,theta=270*DEGREES)
+ self.play(ShowCreation(cube))
+
+ dot = Sphere()
+ dot.scale(0.1)
+ dot.move_to(np.array([1,0.5,1]))
+ dot.set_fill(RED)
+
+ #dot = Dot(np.array([1,0.5,1]), color = RED)
+ temp_func = TextMobject("T(x,y,z)")
+ temp_func.next_to(dot,RIGHT)
+ temp_func.set_color(RED)
+ temp_func_trans = TextMobject("T(1,0.5,1)")
+ temp_func_trans.next_to(dot,RIGHT)
+ temp_func_trans.set_color(RED)
+ temp = TextMobject(r"$36 ^\circ$")
+ temp.next_to(dot,RIGHT)
+ temp.set_color(RED_E)
+
+
+ self.play(ShowCreation(dot))
+ self.play(ShowCreation(temp_func))
+ self.play(Transform(temp_func, temp_func_trans))
+ self.wait(1)
+ self.play(Transform(temp_func, temp))
+
+
+
+
+ dot1 = Sphere()
+ dot1.scale(0.1)
+ dot1.move_to(np.array([-1,-0.8,-1.5]))
+ dot1.set_fill(BLUE_E)
+ #dot1 = Dot(np.array([-1,-0.8,-1.5]), color = BLUE)
+ temp_func1 = TextMobject("T(x,y,z)")
+ temp_func1.next_to(dot1,LEFT)
+ temp_func1.set_color(BLUE)
+ temp_func_trans1 = TextMobject("T(-1,-0.8,-1.5)")
+ temp_func_trans1.next_to(dot1,LEFT)
+ temp_func_trans1.set_color(BLUE)
+ temp1 = TextMobject(r"$24 ^\circ$")
+ temp1.next_to(dot1,LEFT)
+ temp1.set_color(BLUE)
+
+ self.play(ShowCreation(dot1))
+ self.play(ShowCreation(temp_func1))
+ self.play(Transform(temp_func1, temp_func_trans1))
+ self.wait(1)
+ self.play(Transform(temp_func1, temp1))
+
+ self.play(FadeOut(temp_func))
+ self.play(FadeOut(temp_func1))
+
+
+ self.move_camera(phi=80* DEGREES,theta=45*DEGREES,run_time=3)
+
+ self.begin_ambient_camera_rotation(rate=0.2)
+ self.wait(4)
+ self.stop_ambient_camera_rotation()
+ self.wait(2)
+
+
+
+
+class AddTempScale(Scene):
+ def construct(self):
+ temp_scale = ImageMobject("tempscale.png")
+ temp_scale.scale(4)
+ temp_scale.move_to(2*RIGHT)
+ self.play(ShowCreation(temp_scale))
+
+
+ temp_func = TextMobject("T(x,y,z)")
+ temp_func.move_to(3*UP +2*LEFT)
+ temp_func.set_color(RED)
+ temp_func_trans = TextMobject("T(1,0.5,1)")
+ temp_func_trans.move_to(3*UP +2*LEFT)
+ temp_func_trans.set_color(RED)
+ temp = TextMobject(r"$36 ^\circ$")
+ temp.set_color(RED)
+ temp.move_to(3*UP +2*LEFT)
+ temp.scale(0.7)
+
+ self.play(ShowCreation(temp_func))
+ self.play(Transform(temp_func, temp_func_trans))
+ self.wait(1)
+ self.play(Transform(temp_func, temp))
+ self.play(ApplyMethod(temp_func.move_to, 1.8*UP +1.8*RIGHT))
+
+
+ temp_func1 = TextMobject("T(x,y,z)")
+ temp_func1.move_to(2*UP +2*LEFT)
+ temp_func1.set_color(BLUE)
+ temp_func_trans1 = TextMobject("T(-1,-0.8,-1.5)")
+ temp_func_trans1.move_to(2*UP +2*LEFT)
+ temp_func_trans1.set_color(BLUE)
+ temp1 = TextMobject(r"$24 ^\circ$")
+ temp1.set_color(BLUE)
+ temp1.move_to(2*UP +2*LEFT)
+ temp1.scale(0.7)
+
+ self.play(ShowCreation(temp_func1))
+ self.play(Transform(temp_func1, temp_func_trans1))
+ self.wait(1)
+ self.play(Transform(temp_func1, temp1))
+ self.play(ApplyMethod(temp_func1.move_to, 0.6*UP +1.8*RIGHT))
+
+
+
+ transtext = TextMobject("Scalar Function Transform:")
+ transtext.set_color(GREEN)
+ transtext1 = TextMobject(r"$\mathbb{R}^3 \rightarrow \mathbb{R}$")
+ transtext1.set_color(YELLOW_E)
+ transtext.move_to(3*UP +3*LEFT)
+ transtext1.next_to(transtext,DOWN)
+ self.play(Write(transtext))
+ self.play(Write(transtext1))
+ self.wait(2)
+
+
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/file7_neural_nets.py b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/file7_neural_nets.py
new file mode 100644
index 0000000..eb6bf45
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/file7_neural_nets.py
@@ -0,0 +1,177 @@
+from manimlib.imports import *
+
+class SigmoidFunc(GraphScene):
+ CONFIG = {
+ "x_min": -4,
+ "x_max": 4,
+ "y_min": -1,
+ "y_max": 1,
+ "graph_origin": ORIGIN + 0.8*DOWN,
+ "x_labeled_nums": list(range(-4, 5)),
+ "y_labeled_nums": list(range(-1, 2)),
+ "y_axis_height": 4.5,
+ }
+ def construct(self):
+ XTD = self.x_axis_width/(self.x_max- self.x_min)
+ YTD = self.y_axis_height/(self.y_max- self.y_min)
+
+ topic = TextMobject("Sigmoid Function")
+ topic.move_to(3.2*UP)
+ topic.set_color_by_gradient(RED, ORANGE, YELLOW, GREEN, BLUE, PURPLE)
+
+ self.setup_axes(animate = True)
+ sigmoid_func = self.get_graph(lambda x : (1/(1 + np.exp(-x))), x_min = -4, x_max = 4)
+ sigmoid_lab = self.get_graph_label(sigmoid_func, label = r"\frac{1}{1 + e^{-z}}")
+
+
+
+
+ self.play(ShowCreation(sigmoid_func),Write(sigmoid_lab))
+ self.play(Write(topic))
+ self.wait(2)
+ self.play(FadeOut(sigmoid_func), FadeOut(sigmoid_lab))
+ self.wait(1)
+
+
+
+class NeuralNet(GraphScene):
+ def construct(self):
+
+ sigmoid_exp = TextMobject(r"g(z) = g($\theta^T$ X) = $\frac{1}{1 + e^{-z}}$")
+ sigmoid_exp.move_to(3*UP + 4*LEFT)
+ sigmoid_exp.scale(0.8)
+ sigmoid_exp.set_color(BLUE)
+ sigmoid_exp1 = TextMobject(r"Predict: 'y = 1'",r"When g(z) $\geq$ 0.5, z $\geq$ 0, $\theta^T$ X $\geq$ 0")
+ sigmoid_exp2 = TextMobject(r"Predict: 'y = 0'", r"When g(z) $\leq$ 0.5, z $\leq$ 0, $\theta^T$ X $\leq$ 0")
+ sigmoid_exp1.scale(0.5)
+ sigmoid_exp2.scale(0.5)
+ sigmoid_exp1.set_color(PURPLE)
+ sigmoid_exp2.set_color(PURPLE)
+
+ sigmoid_exp1[0].next_to(sigmoid_exp, 1.5*DOWN)
+ sigmoid_exp1[1].next_to(sigmoid_exp1[0], DOWN)
+ sigmoid_exp2[0].next_to(sigmoid_exp1[1], 1.5*DOWN)
+ sigmoid_exp2[1].next_to(sigmoid_exp2[0], DOWN)
+
+
+ self.play(Write(sigmoid_exp))
+ self.play(Write(sigmoid_exp1[0]), Write(sigmoid_exp1[1]))
+ self.play(Write(sigmoid_exp2[0]), Write(sigmoid_exp2[1]))
+ self.wait(2)
+
+
+ neuron1 = Circle()
+ neuron1.set_fill(YELLOW_A, opacity = 0.5)
+
+ neuron2 = Circle()
+ neuron2.set_fill(ORANGE, opacity = 0.5)
+
+ neuron3 = Circle()
+ neuron3.set_fill(GREEN_E, opacity = 0.5)
+
+ neuron1.move_to(2*UP+RIGHT)
+ neuron2.move_to(2*DOWN+RIGHT)
+ neuron3.move_to(4*RIGHT)
+
+ arrow1 = Arrow(neuron1.get_right(),neuron3.get_left(),buff=0.1)
+ arrow1.set_color(RED)
+ arrow2 = Arrow(neuron2.get_right(),neuron3.get_left(),buff=0.1)
+ arrow2.set_color(RED)
+
+ arrow3 = Arrow(neuron3.get_right(),7*RIGHT,buff=0.1)
+ arrow3.set_color(RED)
+
+
+ sign1 = TextMobject("+1")
+ sign1.move_to(2*UP+RIGHT)
+ sign1.scale(2)
+ sign2 = TextMobject(r"$x_1$")
+ sign2.move_to(2*DOWN+RIGHT)
+ sign2.scale(2)
+ sign3 = TextMobject(r"$h_{\theta}(x)$")
+ sign3.move_to(6*RIGHT+0.4*DOWN)
+ sign3.scale(0.7)
+ sign4 = TextMobject(r"$= g(10 - 20x_1)$")
+ sign4.next_to(sign3,DOWN)
+ sign4.scale(0.5)
+ sign5 = TextMobject(r"$= g(10 - 20x_1)$")
+ sign5.next_to(sign3,DOWN)
+ sign5.scale(0.5)
+ sign6 = TextMobject(r"$= g(10 - 20x_1)$")
+ sign6.next_to(sign3,DOWN)
+ sign6.scale(0.5)
+
+
+ weight1 = TextMobject("10")
+ weight1.next_to(arrow1,UP)
+ weight2 = TextMobject("-20")
+ weight2.next_to(arrow2,DOWN)
+
+ gate = TextMobject("NOT GATE")
+ gate.set_color_by_gradient(RED, ORANGE, YELLOW, GREEN, BLUE, PURPLE)
+ gate.scale(1.5)
+ gate.move_to(3*RIGHT+3.5*UP)
+
+
+
+ truth_table = TextMobject(r"\begin{displaymath}\begin{array}{|c|c|} x & y\\ \hline 1 & 0 \\0 & 1 \\\end{array}\end{displaymath}")
+ truth_table.next_to(sigmoid_exp2[1], 3*DOWN)
+
+ values = TextMobject("1", "0")
+ values.scale(2)
+
+ sign4_trans1 = TextMobject(r"$= g(10 - 20(1))$")
+ sign4_trans2 = TextMobject(r"$= g(10 - 20(0))$")
+ sign4_trans1.next_to(sign3,DOWN)
+ sign4_trans2.next_to(sign3,DOWN)
+ sign4_trans1.scale(0.5)
+ sign4_trans2.scale(0.5)
+
+
+
+ output1 = TextMobject("y = 0")
+ output2 = TextMobject("y = 1")
+ output1.next_to(sign4,DOWN)
+ output2.next_to(sign4,DOWN)
+ output1.scale(1.5)
+ output2.scale(1.5)
+
+
+
+ self.play(ShowCreation(neuron1),ShowCreation(neuron2))
+ self.play(ShowCreation(neuron3))
+ self.play(ShowCreation(sign1),ShowCreation(sign2))
+ self.wait(1)
+
+ self.play(GrowArrow(arrow1))
+ self.play(GrowArrow(arrow2))
+ self.play(ShowCreation(weight1),ShowCreation(weight2))
+
+
+
+ self.play(GrowArrow(arrow3))
+ self.play(Write(sign3),Write(sign4))
+
+ self.play(Write(gate))
+ self.play(ShowCreation(truth_table))
+
+ self.play(ApplyMethod(values[0].move_to, 2*DOWN+RIGHT))
+ self.play(FadeOut(values[0]))
+ self.play(Transform(sign4,sign4_trans1))
+ self.play(Write(output1))
+ self.wait(1)
+ self.play(FadeOut(output1))
+ self.play(Transform(sign4, sign5))
+
+
+ self.play(ApplyMethod(values[1].move_to, 2*DOWN+RIGHT))
+ self.play(FadeOut(values[1]))
+ self.play(Transform(sign4,sign4_trans2))
+ self.play(Write(output2))
+ self.wait(1)
+ self.play(FadeOut(output2))
+ self.play(Transform(sign4, sign6))
+
+ self.wait(2)
+
+
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/gifs/file1_scalar_functions.gif b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/gifs/file1_scalar_functions.gif
new file mode 100644
index 0000000..bea9c7b
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/gifs/file1_scalar_functions.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/gifs/file2_domain_range.gif b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/gifs/file2_domain_range.gif
new file mode 100644
index 0000000..6801e4f
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/gifs/file2_domain_range.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/gifs/file3_parabola_example.gif b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/gifs/file3_parabola_example.gif
new file mode 100644
index 0000000..9576b4a
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/gifs/file3_parabola_example.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/gifs/file4_level_curves.gif b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/gifs/file4_level_curves.gif
new file mode 100644
index 0000000..b4ac106
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/gifs/file4_level_curves.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/gifs/file5_level_surface.gif b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/gifs/file5_level_surface.gif
new file mode 100644
index 0000000..e4dc80d
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/gifs/file5_level_surface.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/gifs/file6_scalar_function_application.gif b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/gifs/file6_scalar_function_application.gif
new file mode 100644
index 0000000..8bb176a
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/gifs/file6_scalar_function_application.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/gifs/file7_neural_nets.gif b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/gifs/file7_neural_nets.gif
new file mode 100644
index 0000000..a22f1b8
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/multivariable-functions-and-paritial-derivatives/scalar-functions/gifs/file7_neural_nets.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/divergence-gauss-theorem/README.md b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/divergence-gauss-theorem/README.md
new file mode 100644
index 0000000..17fcde0
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/divergence-gauss-theorem/README.md
@@ -0,0 +1,4 @@
+**file1_flux@_various_points.py**
+![file1_flux@_various_points](file1_flux@_various_points.gif)
+**file2_different_valuesof_Div.py**
+![file2_different_valuesof_Div](file2_different_valuesof_Div.gif)
diff --git a/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/divergence-gauss-theorem/file1_flux@_various_points.gif b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/divergence-gauss-theorem/file1_flux@_various_points.gif
new file mode 100644
index 0000000..6c32b94
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/divergence-gauss-theorem/file1_flux@_various_points.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/divergence-gauss-theorem/file1_flux@_various_points.py b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/divergence-gauss-theorem/file1_flux@_various_points.py
new file mode 100644
index 0000000..6727982
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/divergence-gauss-theorem/file1_flux@_various_points.py
@@ -0,0 +1,60 @@
+from manimlib.imports import *
+def pendulum_vector_field_func(point):
+ #theta, omega = point[:2]
+ return np.array([
+ 5*point[0]+point[1],
+ 3*point[1]+3*point[1],
+ 0,
+ ])
+class SF(Scene):
+ CONFIG = {
+ #"func": cylinder_flow_vector_field,
+ "flow_time": 5,
+ }
+ def initialize_vector_field(self):
+ self.vector_field = VectorField(
+ pendulum_vector_field_func,
+ )
+ self.vector_field.sort(get_norm)
+ def construct(self):
+ # plane = NumberPlane(color=RED)
+ # plane.add(plane.get_axis_labels())
+ # self.add(plane)
+
+ A=TextMobject("The net flux through the green circular region is zero",tex_to_color_map={"green": GREEN})
+ B=TextMobject("The net flux through the blue circular region is non-zero",tex_to_color_map={"blue": BLUE})
+
+ c1=Circle(color=GREEN, radius=1.5)
+ c1.shift(4*LEFT+2.2*UP)
+ c2=Circle(color=BLUE, radius=1.5)
+
+
+
+
+ self.play(ShowCreation(A))
+ self.wait(0.5)
+ self.play(ApplyMethod(A.shift, (0.8*UP+0.2*LEFT)))
+ self.play(ShowCreation(B))
+ # self.play(ApplyMethod(B.shift, (2*UP)))
+ self.wait(2)
+ self.play(FadeOut(A),FadeOut(B))
+ self.initialize_vector_field()
+ field = self.vector_field
+ self.play(ShowCreation(field), run_time=4)
+ self.play(ShowCreation(c1))
+ self.play(ShowCreation(c2))
+ self.wait(1)
+ lines = StreamLines(
+ pendulum_vector_field_func,
+ virtual_time=3,
+ min_magnitude=0,
+ max_magnitude=2,
+ )
+ self.add(AnimatedStreamLines(
+ lines,
+ line_anim_class=ShowPassingFlash
+ ))
+ self.wait(2)
+ phase_point = VectorizedPoint(1*UP+1*RIGHT)
+ self.add(move_along_vector_field(phase_point, pendulum_vector_field_func))
+ self.wait(2)
diff --git a/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/divergence-gauss-theorem/file2_different_valuesof_Div.gif b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/divergence-gauss-theorem/file2_different_valuesof_Div.gif
new file mode 100644
index 0000000..477c311
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/divergence-gauss-theorem/file2_different_valuesof_Div.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/divergence-gauss-theorem/file2_different_valuesof_Div.py b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/divergence-gauss-theorem/file2_different_valuesof_Div.py
new file mode 100644
index 0000000..921047d
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/divergence-gauss-theorem/file2_different_valuesof_Div.py
@@ -0,0 +1,91 @@
+from manimlib.imports import *
+class Div(Scene):
+ def construct(self):
+ one=TextMobject(r"Div$ \vec{F} < 0$ ").set_color(RED)
+ two=TextMobject(r"Div$ \vec{F} = 0$ ").set_color(BLUE)
+ three=TextMobject(r"Div$ \vec{F} > 0$ ").set_color(YELLOW)
+
+ one.shift(2.3*DOWN)
+ two.shift(2.3*DOWN)
+ three.shift(2.3*DOWN)
+
+
+ a=Dot(color=RED)
+ a.shift(0.1*LEFT)
+ b=Dot(color=BLUE)
+ b.shift(0.1*LEFT)
+ c=Dot(color=YELLOW)
+ c.shift(0.1*LEFT)
+
+ rot=[0*DEGREES,45*DEGREES,90*DEGREES,135*DEGREES,180*DEGREES,225*DEGREES,270*DEGREES,315*DEGREES]
+ rot2=[180*DEGREES,180*DEGREES,180*DEGREES,180*DEGREES,180*DEGREES,180*DEGREES,180*DEGREES,180*DEGREES]
+ shift=[RIGHT,0.7*RIGHT+0.7*UP,UP,0.7*LEFT+0.7*UP,LEFT,0.7*LEFT+0.7*DOWN,DOWN,0.7*RIGHT+0.7*DOWN]
+ shift2=[RIGHT,RIGHT+UP,RIGHT+DOWN,UP,DOWN,LEFT,LEFT+UP,LEFT+DOWN]
+
+
+
+ u=[Vector(color=RED),Vector(color=RED),Vector(color=RED),Vector(color=RED),
+ Vector(color=RED),Vector(color=RED),Vector(color=RED),Vector(color=RED)]
+
+
+ [u[i].rotate(rot[i]) for i in range(8) ]
+ [u[i].rotate(rot2[i]) for i in range(8) ]
+ [u[i].shift(shift[i]) for i in range(8) ]
+
+
+ divone=VGroup(*u)
+ divone.shift(0.6*LEFT)
+
+
+ v=[Vector(color=BLUE),Vector(color=BLUE),Vector(color=BLUE),Vector(color=BLUE),
+ Vector(color=BLUE),Vector(color=BLUE),Vector(color=BLUE),Vector(color=BLUE)]
+
+
+ [v[i].rotate(45*DEGREES) for i in range(8)]
+ [v[i].shift(shift2[i]) for i in range(8) ]
+
+ divtwo=VGroup(*v)
+ divtwo.shift(0.6*LEFT)
+
+
+ w=[Vector(color=YELLOW),Vector(color=YELLOW),Vector(color=YELLOW),Vector(color=YELLOW),
+ Vector(color=YELLOW),Vector(color=YELLOW),Vector(color=YELLOW),Vector(color=YELLOW)]
+
+
+ [w[i].rotate(rot[i]) for i in range(8)]
+ [w[i].shift(shift[i]) for i in range(8) ]
+
+
+ divthree=VGroup(*w)
+ divthree.shift(0.6*LEFT)
+
+
+
+
+ self.play(ShowCreation(a),ShowCreation(divone))
+ self.play(ShowCreation(one))
+ self.wait(1)
+ self.play(FadeOut(a),FadeOut(divone),FadeOut(one))
+
+ self.play(ShowCreation(b),ShowCreation(divtwo))
+ self.play(ShowCreation(two))
+ self.wait(1)
+ self.play(FadeOut(b),FadeOut(divtwo),FadeOut(two))
+
+
+ self.play(ShowCreation(c),ShowCreation(divthree))
+ self.play(ShowCreation(three))
+ self.wait(1)
+ self.play(FadeOut(c),FadeOut(divthree),FadeOut(three))
+ self.wait(0.5)
+
+
+
+
+
+
+
+
+
+
+
diff --git a/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/flux/README.md b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/flux/README.md
new file mode 100644
index 0000000..97d6d10
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/flux/README.md
@@ -0,0 +1,6 @@
+**file1_flux_through_circle.py**
+![file1_flux_through_circle](file1_flux_through_circle.gif)
+**file3_normal_vector.py**
+![file3_normal_vector](file3_normal_vector.gif)
+**file4_cube_surface.py**
+![file4_cube_surface](file4_cube_surface.gif)
diff --git a/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/flux/file1_flux_through_circle.gif b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/flux/file1_flux_through_circle.gif
new file mode 100644
index 0000000..c00076b
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/flux/file1_flux_through_circle.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/flux/file1_flux_through_circle.py b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/flux/file1_flux_through_circle.py
new file mode 100644
index 0000000..e418a96
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/flux/file1_flux_through_circle.py
@@ -0,0 +1,43 @@
+from manimlib.imports import *
+def pendulum_vector_field_func(point):
+ #theta, omega = point[:2]
+ return np.array([
+ point[0],
+ point[1],
+ point[2],
+ ])
+class F2D(Scene):
+ CONFIG = {
+ # "func": cylinder_flow_vec or_field,
+ "flow_time": 5,
+ }
+ def initialize_vector_field(self):
+ self.vector_field = VectorField(
+ pendulum_vector_field_func,
+ )
+ self.vector_field.sort(get_norm)
+ def construct(self):
+ # plane = NumberPlane(color=RED)
+ # plane.add(plane.get_axis_labels())
+ # self.add(plane)
+ self.initialize_vector_field()
+
+ field = self.vector_field
+ c1=Circle(radius=3,color=BLUE)
+ self.play(ShowCreation(field), run_time=7)
+ self.play(ShowCreation(c1))
+ self.wait(3)
+ lines = StreamLines(
+ pendulum_vector_field_func,
+ virtual_time=3,
+ min_magnitude=0,
+ max_magnitude=2,
+ )
+ self.add(AnimatedStreamLines(
+ lines,
+ line_anim_class=ShowPassingFlash
+ ))
+ self.wait(2)
+ phase_point = VectorizedPoint(1*UP+1*RIGHT)
+ self.add(move_along_vector_field(phase_point, pendulum_vector_field_func))
+ self.wait(2)
diff --git a/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/flux/file3_normal_vector.gif b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/flux/file3_normal_vector.gif
new file mode 100644
index 0000000..a8f2990
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/flux/file3_normal_vector.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/flux/file3_normal_vector.py b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/flux/file3_normal_vector.py
new file mode 100644
index 0000000..a959210
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/flux/file3_normal_vector.py
@@ -0,0 +1,47 @@
+from manimlib.imports import *
+class S(ThreeDScene):
+ def construct(self):
+ axes=ThreeDAxes()
+
+ sphere=Sphere(radius=2,checkerboard_colors=[BLUE_C,BLUE_B],fill_opacity=0.75)
+
+
+ v1=Vector(color=YELLOW,buff=5)
+ v1.rotate(PI/4,axis=DOWN)
+ v1.shift(1.5*RIGHT+1.5*OUT)
+
+ v2=Vector(color=RED,buff=5)
+ v2.rotate(PI/4,axis=DOWN)
+ v2.rotate(PI,axis=DOWN)
+ v2.shift(0.77*RIGHT+0.77*OUT)
+
+
+
+
+ n1=TextMobject(r"$\vec{n}$",color=YELLOW)
+ n2=TextMobject(r"$-\vec{n}$",color= RED)
+ n1.rotate(PI/2,axis=RIGHT)
+ n1.shift(2*RIGHT+2*OUT)
+ n2.rotate(PI/2,axis=RIGHT)
+ n2.shift(0.42*RIGHT+0.42*OUT)
+
+
+
+ self.set_camera_orientation(phi=75 * DEGREES,theta=-45*DEGREES)
+ # self.add(mobius)
+ # self.play(ShowCreation(axes))
+ self.play(ShowCreation(axes))
+ # self.play(ShowCreation(vg))
+ self.play(ShowCreation(sphere))
+ self.wait(0.7)
+ self.play(ShowCreation(v1, run_time=2))
+ self.play(ShowCreation(n1))
+ self.wait(1)
+ self.begin_ambient_camera_rotation(rate=0.65)
+ self.wait(2)
+ self.play(ShowCreation(v2, run_time=3))
+ self.wait(3)
+ self.play(ShowCreation(n2))
+
+ self.stop_ambient_camera_rotation()
+ self.wait(1.2)
diff --git a/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/flux/file4_cube_surface.gif b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/flux/file4_cube_surface.gif
new file mode 100644
index 0000000..001edb8
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/flux/file4_cube_surface.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/flux/file4_cube_surface.py b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/flux/file4_cube_surface.py
new file mode 100644
index 0000000..146d955
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/flux/file4_cube_surface.py
@@ -0,0 +1,196 @@
+from manimlib.imports import*
+class cuber(ThreeDScene):
+ def construct(self):
+
+ axes=ThreeDAxes()
+ cube=Cube()
+ # cube.scale(1)
+ cube.shift(RIGHT+DOWN+OUT)
+
+
+
+ sq3=Square(color=RED, fill_opacity=0.85)
+ sq3.rotate(PI/2, axis=UP)
+ sq3.shift(DOWN+OUT+2*RIGHT)
+
+ x=TextMobject("x")
+ y=TextMobject("y")
+ z=TextMobject("z")
+
+ x.rotate(PI/2, axis=RIGHT)
+ x.rotate(PI/4,axis=OUT)
+ x.shift(5.8*DOWN)
+
+ y.rotate(PI/2, axis=RIGHT)
+ y.rotate(PI/8,axis=OUT)
+ y.shift(5.8*RIGHT)
+
+ z.rotate(PI/2, axis=RIGHT)
+ z.rotate(PI/5,axis=OUT)
+ z.shift(3.2*OUT+0.4*LEFT)
+ axis_label=VGroup(x,y,z)
+
+ v1=Vector(color=YELLOW,buff=15)
+ v1.rotate(PI/4,axis=RIGHT)
+ v1.shift(2*RIGHT+1*DOWN+1*OUT)
+
+
+ n1=TextMobject(r"$\vec{n}$",color=YELLOW)
+ n1.scale(0.8)
+ n1.rotate(PI/2,axis=RIGHT)
+ n1.rotate(PI,axis=OUT)
+ n1.shift(3*RIGHT+1.3*OUT+DOWN)
+
+ spaceloc = [[0,0,2],[1,0,2],[-1,0,2],[2,0,2],[-2,0,2],[3,0,2],[-3,0,2],
+ [0,1,2],[1,1,2],[-1,1,2],[2,1,2],[-2,1,2],[3,1,2],[-3,1,2],
+ [0,-1,2],[1,-1,2],[-1,-1,2],[2,-1,2],[-2,-1,2],[3,-1,2],[-3,-1,2],
+ [0,2,2],[1,2,2],[-1,2,2],[2,2,2],[-2,2,2],[3,2,2],[-3,2,2],
+ [0,-2,2],[1,-2,2],[-1,-2,2],[2,-2,2],[-2,-2,2],[3,-2,2],[-3,-2,2],
+ [0,3,2],[1,3,2],[-1,3,2],[2,3,2],[-2,3,2],[3,3,2],[-3,3,2],
+ [0,3,2],[1,3,2],[-1,3,2],[2,3,2],[-2,3,2],[3,3,2],[-3,3,2],
+ [0,4,2],[1,4,2],[-1,4,2],[2,4,2],[-2,4,2],[3,4,2],[-3,4,2],
+ [0,4,2],[1,4,2],[-1,4,2],[2,4,2],[-2,4,2],[3,4,2],[-3,4,2],
+ [0,5,2],[1,5,2],[-1,5,2],[2,5,2],[-2,5,2],[3,5,2],[-3,5,2],
+ [0,5,2],[1,5,2],[-1,5,2],[2,5,2],[-2,5,2],[3,5,2],[-3,5,2],
+ [0,6,2],[1,6,2],[-1,6,2],[2,6,2],[-2,6,2],[3,6,2],[-3,6,2],
+ [0,1.5,2],[1,1.5,2],[-1,1.5,2],[2,1.5,2],[-2,1.5,2],[3,1.5,2],[-3,1.5,2],
+ [0,3,2],[1,3,2],[-1,3,2],[2,3,2],[-2,3,2],[3,3,2],[-3,3,2]]
+
+
+ veclist1=[Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),
+ Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),
+ Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),
+ Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),
+ Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),
+ Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY)]
+
+
+
+
+
+ [veclist1[i].rotate(PI/4,axis=RIGHT) for i in range(42)]
+ [veclist1[i].rotate(PI/6,axis=OUT) for i in range(42)]
+ [veclist1[i].rotate(PI/8,axis=DOWN) for i in range(42)]
+ vectorfield1=VGroup(*veclist1)
+ [veclist1[i].shift(spaceloc[i]) for i in range(42)]
+
+
+
+
+ veclist2=[Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),
+ Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),
+ Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),
+ Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),
+ Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),
+ Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY)]
+
+
+
+
+
+ [veclist2[i].rotate(PI/4,axis=RIGHT) for i in range(42)]
+ [veclist2[i].rotate(PI/4,axis=RIGHT) for i in range(42)]
+ [veclist2[i].rotate(PI/6,axis=OUT) for i in range(42)]
+ [veclist2[i].rotate(PI/8,axis=DOWN) for i in range(42)]
+ vectorfield2=VGroup(*veclist2)
+ [veclist2[i].shift(spaceloc[i]) for i in range(42)]
+
+
+
+ veclist3=[Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),
+ Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),
+ Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),
+ Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),
+ Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),
+ Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY)]
+
+
+
+
+
+ [veclist3[i].rotate(PI/4,axis=RIGHT) for i in range(42)]
+ [veclist3[i].rotate(PI/4,axis=RIGHT) for i in range(42)]
+ [veclist3[i].rotate(PI/6,axis=OUT) for i in range(42)]
+ [veclist3[i].rotate(PI/8,axis=DOWN) for i in range(42)]
+ vectorfield3=VGroup(*veclist3)
+ [veclist3[i].shift(spaceloc[i]) for i in range(42)]
+
+
+
+
+ veclist4=[Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),
+ Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),
+ Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),
+ Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),
+ Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),
+ Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY)]
+
+
+
+
+
+ [veclist4[i].rotate(PI/4,axis=RIGHT) for i in range(42)]
+ [veclist4[i].rotate(PI/4,axis=RIGHT) for i in range(42)]
+ [veclist4[i].rotate(PI/6,axis=OUT) for i in range(42)]
+ [veclist4[i].rotate(PI/8,axis=DOWN) for i in range(42)]
+ vectorfield4=VGroup(*veclist4)
+ [veclist4[i].shift(spaceloc[i]) for i in range(42)]
+
+
+ vectorfield1.shift(1.5*DOWN)
+ vectorfield2.shift(IN+1.5*DOWN)
+ vectorfield3.shift(2*IN+1.5*DOWN)
+ vectorfield4.shift(3*IN+1.5*DOWN)
+
+
+ vectors=[vectorfield1,vectorfield2,vectorfield3,vectorfield4]
+ vectorfield=VGroup(*vectors)
+ vectorfield.scale(1.3)
+
+
+ fv=[Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),
+ Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),Vector(color=GREY),
+ Vector(color=GREY)
+ ]
+
+ spaceloc2 = [[1.5,0.5,0.5],[1.5,1,0.5],[1.5,1.5,0.5],
+ [1.5,0.5,1],[1.5,1,1],[1.5,1.5,1],
+ [1.5,0.5,1.5],[1.5,1,1.5],[1.5,1.5,1.5]
+ ]
+ [fv[i].rotate(PI/4,axis=RIGHT) for i in range(9)]
+ [fv[i].rotate(PI/6,axis=OUT) for i in range(9)]
+ [fv[i].rotate(PI/8,axis=DOWN) for i in range(9)]
+ [fv[i].shift(spaceloc2[i]) for i in range(9)]
+ fvfield=VGroup(*fv)
+ fvfield.shift(2*DOWN)
+ fvfield.scale(1.3)
+
+ flux=TextMobject("Flux through one side of the cube").set_color(GOLD)
+ flux.shift(3.5*UP+0.5*LEFT)
+
+
+ alll=[vectorfield1,vectorfield2,vectorfield3,vectorfield4,fvfield]
+ alllvectors=VGroup(*alll)
+
+
+
+ self.set_camera_orientation(phi=70 * DEGREES,theta=-75*DEGREES)
+ self.play(ShowCreation(axes),ShowCreation(axis_label))
+ self.begin_ambient_camera_rotation(rate=0.2)
+ self.play(ShowCreation(alllvectors))
+ # self.add(fvfield)
+
+ self.play(ShowCreation(cube, run_time=1))
+
+ self.wait(1)
+ self.play(ShowCreation(sq3))
+ self.wait(1)
+ self.play(FadeOut(cube))
+ self.play(FadeOut(vectorfield))
+ self.add_fixed_in_frame_mobjects(flux)
+ # self.play(ShowCreation(flux))
+ self.wait(1)
+ self.play(ShowCreation(v1),ShowCreation(n1))
+ self.wait(5)
+ self.stop_ambient_camera_rotation()
+ self.wait(1)
diff --git a/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/strokes-theorem/README.md b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/strokes-theorem/README.md
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/strokes-theorem/README.md
diff --git a/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/README.md b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/README.md
new file mode 100644
index 0000000..a1de8b5
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/README.md
@@ -0,0 +1,10 @@
+**file1_projection.py**
+![file1_projection](projection.gif)
+**file2_cube.py**
+![file2_cube](cube.gif)
+**file3_cube_sideC.py**
+![file3_cube_sideC](sideC.gif)
+**file4_pauseandponder.py**
+![file4_pauseandponder](pauseandponder.gif)
+**file5_surface.py**
+![file5_surface](file5_surface.gif)
diff --git a/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/cube.gif b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/cube.gif
new file mode 100644
index 0000000..2035d7a
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/cube.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/file1_projection.py b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/file1_projection.py
new file mode 100644
index 0000000..2d6f067
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/file1_projection.py
@@ -0,0 +1,89 @@
+from manimlib.imports import *
+
+class Surface(ThreeDScene):
+
+ def construct(self):
+ axes=ThreeDAxes()
+ x=TextMobject("X")
+ y=TextMobject("Y")
+ z=TextMobject("Z")
+
+ x.rotate(PI/2, axis=RIGHT)
+ x.rotate(PI/4,axis=OUT)
+ x.shift(5.8*DOWN)
+
+ y.rotate(PI/2, axis=RIGHT)
+ y.rotate(PI/8,axis=OUT)
+ y.shift(5.8*RIGHT)
+
+ z.rotate(PI/2, axis=RIGHT)
+ z.rotate(PI/5,axis=OUT)
+ z.shift(3.2*OUT+0.4*LEFT)
+ axis_label=VGroup(x,y,z)
+
+
+
+
+
+ para_hyp = ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ 2+u/4+np.sin(v)
+ ]),v_min=-3,v_max=-0.4,u_min=-1,u_max=1,
+ resolution=(15, 32)).scale(1)
+ para_hyp.scale(0.3)
+ para_hyp.shift(1.2*RIGHT + 0.2*OUT + 0.4*DOWN)
+ para_hyp.rotate(PI,axis=RIGHT)
+ para_hyp.scale(2.5)
+ # para_hyp.rotate(PI/3.2,axis=OUT)
+ para_hyp2= ParametricSurface(
+ lambda u, v: np.array([
+ u,
+ v,
+ 2+u/4+np.sin(v)
+ ]),v_min=-3,v_max=-0.4,u_min=-1,u_max=1,
+ resolution=(15, 32)).scale(1)
+ para_hyp2.scale(0.3)
+ para_hyp2.shift(1.2*RIGHT + 0.2*OUT + 0.4*DOWN)
+ para_hyp2.rotate(PI,axis=RIGHT)
+ para_hyp2.scale(2.5)
+
+ rec=Rectangle(height=2.11, width=1.58, color=RED, fill_opacity=0.66)
+ rec.shift(1.3*RIGHT + 2.295*DOWN)
+ # rec.scale(2.5)
+
+
+ l1=DashedLine(start=0.5*RIGHT+1.1*DOWN+1.55*OUT,end=0.5*RIGHT+1.1*DOWN)
+ l2=DashedLine(start=2.1*RIGHT+1.1*DOWN+1.25*OUT,end=2.1*RIGHT+1.1*DOWN)
+ l3=DashedLine(start=2.1*RIGHT+3.4*DOWN+1.6*OUT,end=2.1*RIGHT+3.4*DOWN)
+ l4=DashedLine(start=0.5*RIGHT+3.4*DOWN+2*OUT,end=0.5*RIGHT+3.4*DOWN)
+ l=VGroup(l1,l2,l3,l4)
+
+
+
+ s=TextMobject("S",tex_to_color_map={"S": YELLOW})
+ s.rotate(PI/4,axis=RIGHT)
+ s.rotate(PI/15,axis=OUT)
+ s.shift(RIGHT + 2*OUT + 1.5*DOWN)
+ d=TextMobject("D",tex_to_color_map={"D": YELLOW})
+ d.scale(0.85)
+ d.shift(1.26*RIGHT + 2.45*DOWN)
+
+
+
+
+
+ self.set_camera_orientation(phi=75 * DEGREES,theta=-60*DEGREES)
+ self.begin_ambient_camera_rotation(rate=-0.02)
+ self.play(ShowCreation(axes),ShowCreation(axis_label))
+ self.wait(1.3)
+ self.play(ShowCreation(para_hyp))
+ self.play(ShowCreation(s))
+ self.add(para_hyp2)
+ self.play(Transform(para_hyp,rec),run_time=2)
+ self.play(ShowCreation(d))
+
+ self.wait(3)
+
+
diff --git a/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/file2_cube.py b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/file2_cube.py
new file mode 100644
index 0000000..2a094c8
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/file2_cube.py
@@ -0,0 +1,75 @@
+from manimlib.imports import*
+class cuber(ThreeDScene):
+
+ def construct(self):
+
+ axes=ThreeDAxes()
+ cube=Cube(color=RED)
+ # cube.scale(1)
+ cube.shift(RIGHT+DOWN+OUT)
+
+ sq1=Square(side_length=2,color=RED, fill_opacity=0.5)
+ sq1.shift(RIGHT+DOWN)
+ # sq1.scale(1.2)
+ sq2=Square(color=YELLOW, fill_opacity=0.5)
+ sq2.rotate(PI/2,axis=RIGHT)
+ sq2.shift(RIGHT+OUT)
+
+ sq3=Square(color=GREEN , fill_opacity=0.5)
+ sq3.rotate(PI/2, axis=UP)
+ sq3.shift(DOWN+OUT)
+
+ a=TextMobject("side A",tex_to_color_map={"side A": BLACK})
+ b=TextMobject("side B",tex_to_color_map={"side B": BLACK})
+ c=TextMobject("side C",tex_to_color_map={"side C": BLACK})
+ a.rotate(PI/2, axis=RIGHT)
+ a.shift(RIGHT+OUT+2*DOWN)
+ b.rotate(PI/2, axis=OUT)
+ b.rotate(PI/2, axis=UP)
+ b.shift(2*RIGHT+DOWN+OUT)
+ c.shift(RIGHT+DOWN+2*OUT)
+ c.rotate(PI/4, axis=OUT)
+
+
+ axes=ThreeDAxes()
+ x=TextMobject("X")
+ y=TextMobject("Y")
+ z=TextMobject("Z")
+
+ x.rotate(PI/2, axis=RIGHT)
+ x.rotate(PI/4,axis=OUT)
+ x.shift(5.8*DOWN)
+
+ y.rotate(PI/2, axis=RIGHT)
+ y.rotate(PI/8,axis=OUT)
+ y.shift(5.8*RIGHT)
+
+ z.rotate(PI/2, axis=RIGHT)
+ z.rotate(PI/5,axis=OUT)
+ z.shift(3.2*OUT+0.4*LEFT)
+ axis_label=VGroup(x,y,z)
+
+
+
+
+
+
+ self.set_camera_orientation(phi=75 * DEGREES,theta=-67*DEGREES)
+ self.play(ShowCreation(axes),ShowCreation(axis_label))
+ self.play(ShowCreation(cube))
+ self.begin_ambient_camera_rotation(rate=0.04)
+ self.wait(0.7)
+ self.play(ShowCreation(sq1))
+ self.play(ShowCreation(sq2))
+
+ self.play(ShowCreation(sq3))
+ self.wait(0.6)
+ self.play(ShowCreation(a))
+
+ self.play(ShowCreation(b))
+ self.move_camera(phi=60*DEGREES,run_time=1)
+ self.play(ShowCreation(c))
+ self.wait(1)
+ self.wait(2)
+
+
diff --git a/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/file3_cube_sideC.py b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/file3_cube_sideC.py
new file mode 100644
index 0000000..0e6fdaa
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/file3_cube_sideC.py
@@ -0,0 +1,96 @@
+from manimlib.imports import*
+
+
+
+class cuber(ThreeDScene):
+
+ def construct(self):
+
+ axes=ThreeDAxes()
+ cube=Cube(color=RED)
+ # cube.scale(1)
+ cube.shift(RIGHT+DOWN+OUT)
+
+ sq1=Square(side_length=1.95,color=BLUE, fill_opacity=1)
+ sq1.shift(RIGHT+DOWN+2*OUT)
+ # sq1.scale(1.2)
+
+ sq12=Square(side_length=1.95,color=BLUE, fill_opacity=1)
+ sq12.shift(RIGHT+DOWN+2*OUT)
+
+ sq2=Square(side_length=1.95,color=RED, fill_opacity=0.6)
+ sq2.shift(RIGHT+DOWN)
+
+ sq2w=Square(side_length=1.95,color=WHITE, fill_opacity=0.9)
+ sq2w.shift(RIGHT+DOWN)
+
+
+ c=TextMobject("side C",tex_to_color_map={"side C": BLACK})
+
+ dxdy=TextMobject(r"$dxdy$",tex_to_color_map={r"$dxdy$": WHITE})
+ dxdy.scale(0.7)
+ dxdy.rotate(PI/2, axis=RIGHT)
+ dxdy.rotate(PI/7, axis=OUT)
+ dxdy.shift(0.85*RIGHT+0.65*DOWN)
+
+
+
+ c.shift(RIGHT+DOWN+2*OUT)
+ c.rotate(PI/4, axis=OUT)
+
+
+
+ x=TextMobject("X")
+ y=TextMobject("Y")
+ z=TextMobject("Z")
+
+ x.rotate(PI/2, axis=RIGHT)
+ x.rotate(PI/4,axis=OUT)
+ x.shift(5.8*DOWN)
+
+ y.rotate(PI/2, axis=RIGHT)
+ y.rotate(PI/8,axis=OUT)
+ y.shift(5.8*RIGHT)
+
+ z.rotate(PI/2, axis=RIGHT)
+ z.rotate(PI/5,axis=OUT)
+ z.shift(3.2*OUT+0.4*LEFT)
+ axis_label=VGroup(x,y,z)
+
+ v=Vector(color=YELLOW)
+ # v.scale(2)
+ v.rotate(PI/2,axis=DOWN)
+ v.shift(0.4*RIGHT+0.9*DOWN+2.5*OUT)
+
+
+
+
+
+
+ self.set_camera_orientation(phi=60 * DEGREES,theta=-67*DEGREES)
+ self.begin_ambient_camera_rotation(rate=0.008)
+ self.add(axes)
+ self.add(axis_label)
+
+ self.add(cube)
+ # self.move_camera(phi=150*DEGREES,theta=-45*DEGREES, run_time=3)
+ self.wait(1.2)
+ self.add(sq1)
+ self.add(sq12)
+ self.play(ShowCreation(c))
+ self.wait(0.7)
+ self.play(FadeOut(cube))
+ self.wait(0.7)
+ # self.move_camera(phi=75*DEGREES,run_time=2)
+ self.play(ShowCreation(v))
+ self.wait(1)
+ self.play(Transform(sq1,sq2))
+ self.wait(0.7)
+ self.play(ApplyMethod(sq2w.scale, 0.08))
+ self.play(ShowCreation(dxdy))
+ self.wait(2)
+
+
+
+
+
diff --git a/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/file4_pauseandponder.py b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/file4_pauseandponder.py
new file mode 100644
index 0000000..a8b5070
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/file4_pauseandponder.py
@@ -0,0 +1,77 @@
+from manimlib.imports import *
+
+class Surface(ThreeDScene):
+ def construct(self):
+ axes=ThreeDAxes()
+ cylinder = ParametricSurface(
+ lambda u, v: np.array([
+ np.cos(TAU * v),
+ v,
+ u
+ ]),
+ resolution=(6, 32)).fade(0.5) #Resolution of the surfaces
+
+
+ x=TextMobject("X")
+ y=TextMobject("Y")
+ z=TextMobject("Z")
+
+ x.rotate(PI/2, axis=RIGHT)
+ x.rotate(PI/4,axis=OUT)
+ x.shift(5.8*DOWN)
+
+ y.rotate(PI/2, axis=RIGHT)
+ y.rotate(PI/8,axis=OUT)
+ y.shift(5.8*RIGHT)
+
+ z.rotate(PI/2, axis=RIGHT)
+ z.rotate(PI/5,axis=OUT)
+ z.shift(3.2*OUT+0.4*LEFT)
+ axis_label=VGroup(x,y,z)
+
+
+
+ cylinder.rotate(PI/2, axis=RIGHT)
+ cylinder.shift(2*RIGHT+OUT+DOWN)
+ cylinder.scale(1.5)
+
+ self.set_camera_orientation(phi=75 * DEGREES,theta=-85*DEGREES)
+ self.begin_ambient_camera_rotation(rate=0.1)
+ self.play(ShowCreation(axes),ShowCreation(axis_label))
+ self.play(ShowCreation(cylinder))
+ # self.wait(0.7)
+
+
+
+ self.wait(2)
+ self.stop_ambient_camera_rotation()
+ self.wait(0.7)
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
diff --git a/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/file5_surface.gif b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/file5_surface.gif
new file mode 100644
index 0000000..27dcac8
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/file5_surface.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/surface.py b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/file5_surface.py
index a794f46..3c2e145 100644
--- a/FSF-2020/calculus-of-several-variables/integrals-of-multivariable-functions/double-integrals/surface.py
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/file5_surface.py
@@ -1,6 +1,6 @@
from manimlib.imports import *
-class SurfacesAnimation(ThreeDScene):
+class Surf(ThreeDScene):
CONFIG = {
"axes_config": {
@@ -10,7 +10,7 @@ class SurfacesAnimation(ThreeDScene):
"y_max": 8,
"z_min": 0,
"z_max": 6,
- "a":1 ,"b": 6, "c":2 , "d":6,
+ "a":2 ,"b": 6, "c":1 , "d":6,
"axes_shift":-3*OUT + 5*LEFT,
"x_axis_config": {
"tick_frequency": 1,
@@ -49,11 +49,11 @@ class SurfacesAnimation(ThreeDScene):
theta=-80 * DEGREES,
)
- fn_text=TextMobject("$z=f(x,y)$").set_color(PINK)
+ fn_text=TextMobject("$S$").set_color(BLUE)
self.add_fixed_in_frame_mobjects(fn_text)
fn_text.to_edge(TOP,buff=MED_SMALL_BUFF)
- R=TextMobject("R").set_color(BLACK).scale(3)
+ R=TextMobject("D").set_color(BLACK).scale(3)
R.move_to(self.axes.input_plane,IN)
self.add(R)
@@ -64,26 +64,28 @@ class SurfacesAnimation(ThreeDScene):
)
surface.set_style(
fill_opacity=0.8,
- fill_color=PINK,
+ fill_color=YELLOW,
stroke_width=0.8,
stroke_color=WHITE,
)
- self.begin_ambient_camera_rotation(rate=0.07)
+ self.begin_ambient_camera_rotation(rate=0.05)
self.play(Write(surface))
# self.play(LaggedStart(ShowCreation(surface)))
self.get_lines()
# self.play(FadeIn(self.axes.input_plane))
- self.wait(3)
+ self.wait(2)
+ self.stop_ambient_camera_rotation()
+ self.wait(1)
def get_surface(self,axes, func, **kwargs):
config = {
- "u_min": axes.a,
- "u_max": axes.b,
- "v_min": axes.c,
- "v_max": axes.d,
+ "u_min": axes.c,
+ "u_max": axes.d,
+ "v_min": axes.a,
+ "v_max": axes.b,
"resolution": (
(axes.y_max - axes.y_min) // axes.y_axis.tick_frequency,
(axes.x_max - axes.x_min) // axes.x_axis.tick_frequency,
@@ -112,7 +114,7 @@ class SurfacesAnimation(ThreeDScene):
lines=VGroup()
for start , end in zip(surface_corners,
self.region_corners):
- lines.add(self.draw_lines(start,end,"RED"))
+ lines.add(self.draw_lines(start,end,"WHITE"))
for start , end in zip(labels,
self.region_corners):
@@ -153,7 +155,7 @@ class SurfacesAnimation(ThreeDScene):
# Add xy-plane
input_plane = self.get_surface(
- axes, lambda x, t: 0
+ axes, lambda x, t: 1e-5
)
input_plane.set_style(
fill_opacity=0.5,
@@ -214,23 +216,22 @@ class SurfacesAnimation(ThreeDScene):
return axes
def add_axes_labels(self, axes):
- x_label = TexMobject("x")
+ x_label = TexMobject("X")
x_label.next_to(axes.x_axis.get_end(), RIGHT)
axes.x_axis.label = x_label
- y_label = TextMobject("y")
+ y_label = TextMobject("Y")
y_label.rotate(90 * DEGREES, OUT)
y_label.next_to(axes.y_axis.get_end(), UP)
axes.y_axis.label = y_label
- z_label = TextMobject("z")
+ z_label = TextMobject("Z")
z_label.rotate(90 * DEGREES, RIGHT)
z_label.next_to(axes.z_axis.get_zenith(), RIGHT)
axes.z_axis.label = z_label
for axis in axes:
axis.add(axis.label)
return axes
+ ######Code_by_Somnath_Pandit_https://github.com/panditsomnath10016git#########
-
-#uploaded by Somnath Pandit.FSF2020_Double_Integral
diff --git a/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/pauseandponder.gif b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/pauseandponder.gif
new file mode 100644
index 0000000..4308c60
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/pauseandponder.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/projection.gif b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/projection.gif
new file mode 100644
index 0000000..c0ca611
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/projection.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/sideC.gif b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/sideC.gif
new file mode 100644
index 0000000..17b72ff
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/surface-integrals/sideC.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/triple-integrals/README.md b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/triple-integrals/README.md
new file mode 100644
index 0000000..2166a79
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/triple-integrals/README.md
@@ -0,0 +1,6 @@
+**file1_3D_crossproduct.py**
+![file1_3D_crossproduct](file1_3D_crossproduct.gif)
+**file2_cylindrical_coordinates.py**
+![file2_cylindrical_coordinates](file2_cylindrical_coordinates.gif)
+**file2_spherical_coordinates.py**
+![file2_spherical_coordinates](file2_spherical_coordinates.gif)
diff --git a/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/triple-integrals/file1_3D_crossproduct.gif b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/triple-integrals/file1_3D_crossproduct.gif
new file mode 100644
index 0000000..9bde5a1
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/triple-integrals/file1_3D_crossproduct.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/triple-integrals/file1_3D_crossproduct.py b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/triple-integrals/file1_3D_crossproduct.py
new file mode 100644
index 0000000..6720e7e
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/triple-integrals/file1_3D_crossproduct.py
@@ -0,0 +1,120 @@
+from manimlib.imports import*
+
+
+
+class TripleBox(ThreeDScene):
+
+ def construct(self):
+
+ axes=ThreeDAxes()
+ cube=Cube(fill_color=RED,fill_opacity=0.5)
+ cube.scale(0.5)
+ cube.shift(0.5*RIGHT+0.5*DOWN+0.5*OUT)
+ cube.shift(2*RIGHT+2*DOWN+1*OUT)
+
+
+
+ x=TextMobject("x")
+ y=TextMobject("y")
+ z=TextMobject("z")
+
+ x.rotate(PI/2, axis=RIGHT)
+ x.rotate(PI/4,axis=OUT)
+ x.shift(5.8*DOWN)
+
+ y.rotate(PI/2, axis=RIGHT)
+ y.rotate(PI/8,axis=OUT)
+ y.shift(5.8*RIGHT)
+
+ z.rotate(PI/2, axis=RIGHT)
+ z.rotate(PI/5,axis=OUT)
+ z.shift(3.2*OUT+0.4*LEFT)
+ axis_label=VGroup(x,y,z)
+
+
+
+
+ a=TextMobject("a")
+ b=TextMobject("b")
+ c=TextMobject("c")
+ d=TextMobject("d")
+ e=TextMobject("e")
+ f=TextMobject("f")
+
+
+
+ a.rotate(PI/2, axis=RIGHT)
+ a.rotate(PI/2, axis=OUT)
+ a.shift(2*DOWN+0.3*OUT+0.3*LEFT)
+
+ b.rotate(PI/2, axis=RIGHT)
+ b.rotate(PI/2, axis=OUT)
+ b.shift(3*DOWN+0.3*OUT+0.3*LEFT)
+
+
+ c.rotate(PI/2, axis=RIGHT)
+ c.shift(2*RIGHT+0.3*OUT)
+
+ d.rotate(PI/2, axis=RIGHT)
+ d.shift(3*RIGHT+0.3*OUT)
+
+
+ e.rotate(PI/2, axis=RIGHT)
+ e.rotate(PI/4, axis=OUT)
+ e.shift(1*OUT+0.3*DOWN+0.2*LEFT)
+
+
+ f.rotate(PI/2, axis=RIGHT)
+ f.rotate(PI/4, axis=OUT)
+ f.shift(2*OUT+0.3*DOWN+0.2*LEFT)
+
+
+
+ rec1=Rectangle(height=1, width=8,color=RED, fill_color=RED_C, fill_opacity=0.40)
+ rec1.shift(2.5*DOWN+4*RIGHT)
+
+ rec2=Rectangle(height=1, width=14,color=RED, fill_color=RED_C, fill_opacity=0.40)
+ rec2.rotate(PI/2, axis=OUT)
+ rec2.shift(7*DOWN+2.5*RIGHT)
+
+
+ sq=Square(color=RED,fill_opacity=60,side_length=1)
+ sq.shift(2.5*RIGHT+2.5*DOWN)
+
+
+
+ self.set_camera_orientation(phi=70 * DEGREES,theta=-70*DEGREES)
+ self.play(ShowCreation(axes),ShowCreation(axis_label))
+ self.begin_ambient_camera_rotation(rate=0.04)
+ self.play(ShowCreation(a),ShowCreation(b))
+ self.wait(0.5)
+ self.play(ShowCreation(rec1))
+ self.play(ShowCreation(c),ShowCreation(d))
+ self.play(ShowCreation(rec2))
+ self.add(sq)
+ self.wait(0.5)
+
+ self.play(FadeOut(rec1),FadeOut(rec2))
+ self.wait(1)
+
+ self.play(ShowCreation(e),ShowCreation(f))
+ self.wait(0.5)
+ self.play(ApplyMethod(sq.shift, 1*OUT))
+ self.wait(0.5)
+ self.play(Transform(sq,cube))
+
+
+ self.wait(0.5)
+
+
+
+ self.wait(0.5)
+
+
+
+
+ self.wait(3)
+ self.stop_ambient_camera_rotation()
+ self.wait(1.5)
+
+
diff --git a/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/triple-integrals/file2_cylindrical_coordinates.gif b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/triple-integrals/file2_cylindrical_coordinates.gif
new file mode 100644
index 0000000..e913750
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/triple-integrals/file2_cylindrical_coordinates.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/triple-integrals/file2_cylindrical_coordinates.py b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/triple-integrals/file2_cylindrical_coordinates.py
new file mode 100644
index 0000000..d441dc0
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/triple-integrals/file2_cylindrical_coordinates.py
@@ -0,0 +1,164 @@
+from manimlib.imports import*
+class Cy(ThreeDScene):
+
+ def construct(self):
+
+ axes=ThreeDAxes()
+ x=TextMobject("X")
+ y=TextMobject("Y")
+ z=TextMobject("Z")
+
+ x.rotate(PI/2, axis=RIGHT)
+ x.rotate(PI/4,axis=OUT)
+ x.shift(5.8*DOWN)
+
+ y.rotate(PI/2, axis=RIGHT)
+ y.rotate(PI/8,axis=OUT)
+ y.shift(5.8*RIGHT)
+
+ z.rotate(PI/2, axis=RIGHT)
+ z.rotate(PI/5,axis=OUT)
+ z.shift(3.2*OUT+0.4*LEFT)
+ axis_label=VGroup(x,y,z)
+
+
+
+
+
+
+
+ x1=TextMobject("$x_{1}$")
+ y1=TextMobject("$y_{1}$")
+ z1=TextMobject("$z_{1}$")
+
+
+
+
+ x1.rotate(PI/2, axis=RIGHT)
+ x1.rotate(PI/2, axis=OUT)
+ x1.shift(2*DOWN+0.3*OUT+0.3*LEFT)
+
+ y1.rotate(PI/2, axis=RIGHT)
+ y1.shift(2*RIGHT+0.3*OUT)
+
+ z1.rotate(PI/2, axis=RIGHT)
+ z1.rotate(PI/4, axis=OUT)
+ z1.shift(2*OUT+0.3*DOWN+0.2*LEFT)
+
+
+ d1=Dot(color=RED,radius=0.05)
+ d2=Dot(color=RED,radius=0.05)
+ d3=Dot(color=RED,radius=0.05)
+
+
+ d1.shift(2*DOWN)
+ d1.rotate(PI/2,axis=UP)
+
+ d2.rotate(PI/2, axis=RIGHT)
+ d2.shift(2*RIGHT)
+
+ d3.rotate(PI/2, axis=RIGHT)
+ d3.rotate(PI/4, axis=OUT)
+ d3.shift(2*OUT)
+
+
+
+ l1=DashedLine(color=RED)
+ l1.scale(5)
+ l1.shift(2*DOWN+5*RIGHT)
+
+ l2=DashedLine(color=RED)
+ l2.scale(5)
+ l2.rotate(PI/2, axis=IN)
+ l2.shift(2*RIGHT+5*DOWN)
+
+ l3=DashedLine(color=RED)
+ l3.scale(5)
+ l3.rotate(PI/4,axis=IN)
+ l3.shift(2*OUT+4*RIGHT+4*DOWN)
+
+ point=Sphere(radius=0.02, checkerboard_colors=[BLUE,BLUE])
+ point.shift(2*RIGHT+2*DOWN)
+
+ proj=Line()
+ proj.scale(1.414)
+ proj.rotate(PI/4,axis=IN)
+ proj.shift(1*RIGHT+1*DOWN)
+
+
+ projl=DashedLine()
+ projl.rotate(PI/2, axis=DOWN)
+ projl.shift(1*OUT+2*RIGHT+2*DOWN)
+
+ p=TextMobject("$P(x,y,z)$")
+ p.scale(0.6)
+ p.rotate(PI/2, axis=RIGHT)
+ p.rotate(PI/9, axis=OUT)
+ p.shift(2.9*RIGHT+2.5*DOWN+2.3*OUT)
+
+ rho=TextMobject(r"$\rho$",tex_to_color_map={r"$\rho$": YELLOW})
+ rho.rotate(PI/2, axis=RIGHT)
+ rho.shift(1.5*RIGHT+1.36*DOWN+0.2*OUT)
+
+
+
+
+ carrow=CurvedArrow(start_point=1*DOWN, end_point=0.5*RIGHT+0.5*DOWN)
+
+
+ phi=TextMobject(r"$\phi$",tex_to_color_map={"$\phi$": YELLOW})
+ phi.scale(0.93)
+ phi.rotate(PI/2, axis=RIGHT)
+ phi.shift(0.3*RIGHT+1.3*DOWN)
+
+
+
+
+
+
+
+
+
+
+ self.set_camera_orientation(phi=70 * DEGREES,theta=-15*DEGREES)
+ self.play(ShowCreation(axes),ShowCreation(axis_label))
+ self.begin_ambient_camera_rotation(rate=-0.1)
+
+ self.play(ShowCreation(x1),ShowCreation(d1))
+ self.wait(0.5)
+ self.play(ShowCreation(l1))
+ self.wait(1)
+ self.play(ShowCreation(y1),ShowCreation(d2))
+ self.wait(0.5)
+ self.play(ShowCreation(l2))
+ self.wait(1)
+ self.add(point)
+ self.wait(0.5)
+ self.play(FadeOut(l1),FadeOut(l2))
+ self.wait(0.5)
+ self.play(ShowCreation(proj))
+ self.wait(0.64)
+ self.stop_ambient_camera_rotation()
+ self.play(ShowCreation(rho))
+ self.wait(1)
+
+ self.play(ShowCreation(z1),ShowCreation(d3))
+ self.wait(0.5)
+ self.play(ShowCreation(l3))
+ self.wait(1)
+ self.play(ApplyMethod(point.shift, 2*OUT), ShowCreation(projl))
+ self.play(FadeOut(l3))
+ self.play(ShowCreation(p),FadeOut(projl))
+ self.wait(0.5)
+ # self.play(ShowCreation(vec))
+
+
+
+
+
+ self.wait(1)
+ self.play(ShowCreation(carrow),ShowCreation(phi))
+
+ self.wait(5)
+
+
diff --git a/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/triple-integrals/file2_spherical_coordinates.gif b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/triple-integrals/file2_spherical_coordinates.gif
new file mode 100644
index 0000000..6dc8b17
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/triple-integrals/file2_spherical_coordinates.gif
Binary files differ
diff --git a/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/triple-integrals/file2_spherical_coordinates.py b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/triple-integrals/file2_spherical_coordinates.py
new file mode 100644
index 0000000..7dcc81a
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/triple-and-surface-integrals/triple-integrals/file2_spherical_coordinates.py
@@ -0,0 +1,159 @@
+from manimlib.imports import*
+class Sp(ThreeDScene):
+
+ def construct(self):
+
+ axes=ThreeDAxes()
+ x=TextMobject("X")
+ y=TextMobject("Y")
+ z=TextMobject("Z")
+
+ x.rotate(PI/2, axis=RIGHT)
+ x.rotate(PI/4,axis=OUT)
+ x.shift(5.8*DOWN)
+
+ y.rotate(PI/2, axis=RIGHT)
+ y.rotate(PI/8,axis=OUT)
+ y.shift(5.8*RIGHT)
+
+ z.rotate(PI/2, axis=RIGHT)
+ z.rotate(PI/5,axis=OUT)
+ z.shift(3.2*OUT+0.4*LEFT)
+ axis_label=VGroup(x,y,z)
+
+
+
+
+
+
+
+ x1=TextMobject("$x_{1}$")
+ y1=TextMobject("$y_{1}$")
+ z1=TextMobject("$z_{1}$")
+
+
+
+
+ x1.rotate(PI/2, axis=RIGHT)
+ x1.rotate(PI/2, axis=OUT)
+ x1.shift(2*DOWN+0.3*OUT+0.3*LEFT)
+
+ y1.rotate(PI/2, axis=RIGHT)
+ y1.shift(2*RIGHT+0.3*OUT)
+
+ z1.rotate(PI/2, axis=RIGHT)
+ z1.rotate(PI/4, axis=OUT)
+ z1.shift(2*OUT+0.3*DOWN+0.2*LEFT)
+
+
+ d1=Dot(color=RED,radius=0.05)
+ d2=Dot(color=RED,radius=0.05)
+ d3=Dot(color=RED,radius=0.05)
+
+
+ d1.shift(2*DOWN)
+ d1.rotate(PI/2,axis=UP)
+
+ d2.rotate(PI/2, axis=RIGHT)
+ d2.shift(2*RIGHT)
+
+ d3.rotate(PI/2, axis=RIGHT)
+ d3.rotate(PI/4, axis=OUT)
+ d3.shift(2*OUT)
+
+
+
+ l1=DashedLine(color=RED)
+ l1.scale(5)
+ l1.shift(2*DOWN+5*RIGHT)
+
+ l2=DashedLine(color=RED)
+ l2.scale(5)
+ l2.rotate(PI/2, axis=IN)
+ l2.shift(2*RIGHT+5*DOWN)
+
+ l3=DashedLine(color=RED)
+ l3.scale(5)
+ l3.rotate(PI/4,axis=IN)
+ l3.shift(2*OUT+4*RIGHT+4*DOWN)
+
+ point=Sphere(radius=0.02, checkerboard_colors=[RED,RED])
+
+
+ proj=DashedLine(color=RED_C)
+ proj.scale(1.414)
+ proj.rotate(PI/4,axis=IN)
+ proj.shift(1*RIGHT+1*DOWN)
+
+
+ projl=DashedLine()
+ projl.rotate(PI/2, axis=UP)
+ projl.shift(1*OUT+2*RIGHT+2*DOWN)
+
+ p=TextMobject("$P(x,y,z)$")
+ p.scale(0.6)
+ p.rotate(PI/2, axis=RIGHT)
+ p.rotate(PI/9, axis=OUT)
+ p.shift(2.65*RIGHT+2.5*DOWN+2.3*OUT)
+
+ rho=TextMobject(r"$\rho$",tex_to_color_map={r"$\rho$": YELLOW})
+ rho.rotate(PI/2, axis=RIGHT)
+ rho.shift(1.45*RIGHT+1.9*DOWN+1.94*OUT)
+
+
+
+
+
+ carrow=ArcBetweenPoints(start=1*DOWN, end=0.5*RIGHT+0.5*DOWN)
+ carrow2=ArcBetweenPoints(start=0.5*RIGHT+0.5*DOWN+0.5*OUT, end=0.4*OUT)
+ # carrow2.rotate(PI/2, axis=LEFT)
+ # carrow2.rotate(PI/2, axis=UP)
+
+ theta=TextMobject(r"$\theta$",tex_to_color_map={r"$\theta$": YELLOW})
+ theta.shift((0.75*OUT+0.2*RIGHT))
+ theta.rotate(PI/2,axis=RIGHT)
+ theta.scale(0.9)
+
+
+
+
+ phi=TextMobject(r"$\phi$",tex_to_color_map={"$\phi$": YELLOW})
+ phi.scale(0.93)
+ phi.rotate(PI/2, axis=RIGHT)
+ phi.shift(0.42*RIGHT+1.3*DOWN)
+
+
+
+
+
+
+
+
+
+
+ self.set_camera_orientation(phi=70 * DEGREES,theta=-85*DEGREES)
+ self.play(ShowCreation(axes),ShowCreation(axis_label))
+ self.begin_ambient_camera_rotation(rate=0.009)
+ self.wait(1)
+ self.add(point)
+ self.play(ApplyMethod(point.shift, 2*RIGHT+2*DOWN+2*OUT))
+ self.wait(0.5)
+ self.play(ShowCreation(p))
+ self.wait(0.5)
+ self.play(ShowCreation(vec),ShowCreation(rho))
+ self.wait(1.5)
+ self.play(ApplyMethod(point.shift,2*IN), ShowCreation(projl))
+ self.wait(1)
+ self.play(ShowCreation(proj))
+ self.wait(1.2)
+ self.play(ShowCreation(carrow))
+ self.wait(0.64)
+ self.play(ShowCreation(phi))
+ self.wait(1.3)
+ self.play(ShowCreation(carrow2))
+ self.wait(0.5)
+ self.play(ShowCreation(theta))
+ self.wait(3)
+
+
+