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57 lines
1.6 KiB
Python
57 lines
1.6 KiB
Python
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#!/usr/bin/env python
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from big_ol_pile_of_manim_imports import *
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class VectorDraw(Animation):
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CONFIG = {
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"vector_color" : GREEN_B,
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"line_color" : YELLOW,
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"t_min" : 0,
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"t_max" : 10,
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"run_time" : 7,
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}
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def __init__(self, func, **kwargs):
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digest_config(self, kwargs, locals())
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self.curve = ParametricCurve(
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func, t_min = self.t_min, t_max = self.t_max,
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color = self.line_color
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)
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self.vector = Vector(
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func(self.t_min),
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color = self.vector_color
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)
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mobject = VMobject(self.vector, self.curve) ##First is filler
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Animation.__init__(self, mobject, **kwargs)
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def interpolate_mobject(self, alpha):
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t = alpha*self.t_max + (1 - alpha)*self.t_min
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self.vector.put_start_and_end_on(ORIGIN, self.func(t))
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old_curve = self.starting_mobject.split()[1]
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self.curve.pointwise_become_partial(old_curve, 0, alpha)
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return self
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class Test(Scene):
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def construct(self):
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axes = Axes()
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def func(t):
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return 0.5*(t*np.cos(t)*RIGHT + t*np.sin(t)*UP)
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words = TextMobject("Parametric functions")
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words.set_color(YELLOW)
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words.to_edge(UP+LEFT)
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self.add(words)
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# v = Vector(ORIGIN)
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# v.put_start_and_end_on(LEFT, RIGHT)
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# v.show()
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self.play(ShowCreation(axes))
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self.wait(2)
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self.play(VectorDraw(func))
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self.wait(3)
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self.clear()
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self.add(axes, words)
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self.wait()
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self.play(VectorDraw(func, rate_func = rush_from))
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self.wait()
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