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from manimlib.imports import *
class LimitFunc(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([
u*np.cos(v),
u*np.sin(v),
(np.cos(v)*np.cos(v) - np.sin(v)*np.sin(v))/3
]),u_min=-3,u_max=3,v_min=0,v_max=2*PI,checkerboard_colors=[YELLOW_C, YELLOW_E],
resolution=(15, 32)).scale(2)
self.set_camera_orientation(phi=80 * DEGREES)
self.begin_ambient_camera_rotation(rate=0.3)
self.add(axes)
self.play(Write(limit_func))
self.wait(10)
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