1 files changed, 78 insertions, 0 deletions
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)