Manim CE Question — ApplyFuncExample

[kinggraham336]

Please Explain

I am currently learning the Manim Community v.0.14.0 library. I am a beginner trying to read and write this code so as to understand it.

Animation link: https://user-images.githubusercontent.com/90053391/149587727-e51cf423-f871-4770-b397-807d1363750b.mp4
Link to Manim CE Documentation: https://docs.manim.community/en/stable/reference/manim.mobject.mobject.Mobject.html?highlight=copy()#manim.mobject.mobject.Mobject.copy

ApplyFuncExample-1.2.mp4

This is the code I was analyzing, copied directly from example in the Animation Link above:

                          `from manim import *
                          
                          class ApplyFuncExample(Scene):
                              def construct(self):
                                  circ = Circle().scale(1.5)
                                  circ_ref = circ.copy()
                                  **circ.apply_complex_function(
                                      lambda x: np.exp(x*1j)
                                  )
                                  t = ValueTracker(0)**
                                  circ.add_updater(
                                      lambda x: x.become(circ_ref.copy().apply_complex_function(
                                          lambda x: np.exp(x+t.get_value()*1j)
                                      )).set_color(BLUE)
                                  )
                                  self.add(circ_ref)
                                  self.play(TransformFromCopy(circ_ref, circ))
                                  self.play(t.animate.set_value(TAU), run_time=3)`

The area in the code which I am asking about is in bold. My question is:

What is this lambda function creating? And how does it express itself in the red circle? I see no point for it being there, and I don't understand where it shows up on the animation. If someone can explain to me how this particular code snippet is structured, what it is doing, and how it appears on the animation, I would appreciate it.

[TonyCrane]

you are using CE version, so you are supposed to ask this question on their discord channel or open an issue in their repo instead of here.