manimの作法 その19

概要

manimの作法、調べてみた。
LinearTransformationScene使ってみた。

サンプルコード

from manimlib.imports import *

class test(LinearTransformationScene):
    CONFIG = {
        "matrix": [[2, -5.0 / 3], [-5.0 / 3, 2]],
        "v": [1, 2],
        "w": [2, 1],
        "v_label": "v",
        "w_label": "w",
        "v_color": YELLOW,
        "w_color": MAROON_B,
        "rhs1": "> 0",
        "rhs2": "< 0",
        "foreground_plane_kwargs": {
            "x_radius": 2 * FRAME_WIDTH,
            "y_radius": 2 * FRAME_HEIGHT,
        },
        "equation_scale_factor": 1.5,
    }
    def construct(self):
        v_mob = self.add_vector(self.v, self.v_color, animate=False)
        w_mob = self.add_vector(self.w, self.w_color, animate=False)
        kwargs = {
            "transformation_name": "T",
            "at_tip": True,
            "animate": False,
        }
        v_label = self.add_transformable_label(v_mob, self.v_label, **kwargs)
        w_label = self.add_transformable_label(w_mob, self.w_label, **kwargs)
        start_equation = self.get_equation(v_label, w_label, self.rhs1)
        start_equation.to_corner(UR)
        self.play(Write(start_equation[0::2]), ReplacementTransform(v_label.copy(), start_equation[1]), ReplacementTransform(w_label.copy(), start_equation[3]), )
        self.wait()
        self.add_foreground_mobject(start_equation)
        self.apply_matrix(self.matrix)
        self.wait()
        end_equation = self.get_equation(v_label, w_label, self.rhs2)
        end_equation.next_to(start_equation, DOWN, aligned_edge=RIGHT)
        self.play(FadeIn(end_equation[0]), ReplacementTransform(start_equation[2::2].copy(), end_equation[2::2], ), ReplacementTransform(v_label.copy(), end_equation[1]), ReplacementTransform(w_label.copy(), end_equation[3]), )
        self.wait(2)
    def get_equation(self, v_label, w_label, rhs):
        equation = VGroup(v_label.copy(), TexMobject("\\cdot"), w_label.copy(), TexMobject(rhs), )
        equation.arrange(RIGHT, buff=SMALL_BUFF)
        equation.add_to_back(BackgroundRectangle(equation))
        equation.scale(self.equation_scale_factor)
        return equation

生成した動画

以上。