1 files changed, 40 insertions, 0 deletions
diff --git a/FSF-2020/calculus-of-several-variables/div-curl-grad-and-all-that/gradient/file4_gradient-example-3.py b/FSF-2020/calculus-of-several-variables/div-curl-grad-and-all-that/gradient/file4_gradient-example-3.py
new file mode 100644
index 0000000..7c0ef54
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/div-curl-grad-and-all-that/gradient/file4_gradient-example-3.py
@@ -0,0 +1,40 @@
+from manimlib.imports import *
+import numpy as np
+
+
+def function(coordinate):
+	x,y = coordinate[:2]
+	return np.array([
+		x,
+		y,
+		1/np.cos(x*y),
+	])
+
+class ThreeDVector(ThreeDScene):
+	def construct(self):
+		axes = ThreeDAxes()
+		self.add(axes)
+		self.set_camera_orientation(phi=45*DEGREES,theta=45*DEGREES,distance=40)
+		self.begin_ambient_camera_rotation(rate=0.5)
+
+		surface = ParametricSurface(
+			lambda x, y: np.array([
+			x,
+			y,
+			1/np.cos(x*y),
+		]),u_min=-1.15,u_max=1.15, v_min=-1.15,v_max=1.15).set_color(BLUE_E).fade(0.7).scale(1.4)
+
+		text_func = TexMobject(r"\textbf{Input: Function}").shift(4.4*LEFT+3.3*UP).scale(0.3)
+		text_field = TexMobject(r"\textbf{Output: Vector Field}").shift(4.4*LEFT+3.3*UP).scale(0.7)
+		
+		self.add_fixed_in_frame_mobjects(text_func)
+		self.play(ShowCreation(surface))
+		self.wait(2)
+
+		field = VectorField(function).scale(0.7)
+		self.play(FadeIn(field), FadeOut(text_func))
+		self.add_fixed_in_frame_mobjects(text_field)
+		self.wait()
+
+		self.play(FadeOut(surface))
+		self.wait(2)