Circle on the Complex plane

rhaos68 · Oct 9, 2020 · 43f77e2 · 43f77e2
1 parent 51ac1f7
commit 43f77e2
Showing 1 changed file with 93 additions and 0 deletions.
diff --git a/circle_on_complex_plane.py b/circle_on_complex_plane.py
@@ -0,0 +1,93 @@
+from manimlib.imports import *
+
+def tex(str):
+    return TexMobject(str, ).scale(0.7)
+
+def xy(x, y):
+    return np.array([x, y, 0])
+
+class CircleOnComplexPlane(MovingCameraScene):
+    def construct(self):
+        self.draw_axis()
+        self.draw_circle()
+        self.move_circle()
+
+        self.wait()
+
+    def draw_axis(self):
+        min_x, max_x = -6, -2
+        min_y, max_y = 0, 3.7
+
+        ori = xy(-4, 2)
+
+        def get_line(s,e):
+            return Line(s,e , color=BLUE, stroke_width=5)
+
+        x_axis = get_line(xy(min_x,ori[1]), xy(max_x,ori[1]))
+        y_axis = get_line(xy(ori[0], min_y), xy(ori[0], max_y))
+
+        t_x1=tex("1").scale(0.85).move_to(xy(-3,2)).shift(RIGHT*0.1+DOWN*0.15)
+        t_xm1=tex("-1").scale(0.85).move_to(xy(-5, 2)).shift(LEFT * 0.25 + DOWN * 0.15)
+        t_y1=tex("i").move_to(xy(-4, 3)).shift(LEFT * 0.2+UP*0.2 )
+        t_ym1=tex("-i").move_to(xy(-4, 1)).shift(LEFT * 0.25+DOWN*0.15 )
+
+        self.add(x_axis, y_axis)
+        self.add(t_x1, t_xm1,t_y1,t_ym1)
+
+        self.ori = ori
+
+    def draw_circle(self):
+        ori = self.ori
+
+        circle = Circle(radius=1).move_to(ori)
+        self.add(circle)
+
+        self.circle = circle
+
+    def move_circle(self):
+        circle = self.circle
+        dot = Dot(radius=0.06).move_to(xy(-3,2))
+        cf = self.camera_frame
+
+        self.play(
+            cf.move_to,self.ori,
+            cf.scale, 0.5,
+            run_time=2,
+        )
+        self.play(ShowCreation(dot))
+
+        vt = ValueTracker(0)
+        def update_dot(mob):
+            p = vt.get_value() %  1
+            mob.move_to(circle.point_from_proportion(p))
+
+        dot.add_updater(update_dot)
+
+        self.play(vt.set_value, 1.00, rate_func=linear)
+
+        dot.remove_updater(update_dot)
+
+        ## line위 dot
+        dot2=Dot(radius=0.04, color=YELLOW).move_to(xy(-3,2))
+        line = Line(dot2.center(),dot2.center())
+
+        self.play(
+            ShowCreation(dot2),
+            ShowCreation(line),
+        )
+
+        def update_dot2(mob):
+            y = self.ori[1]
+            x = dot.get_center()[0]
+            mob.move_to(xy(x,y))
+
+        def update_line(mob):
+            new_line = Line(dot.get_center(), dot2.get_center())
+            mob.become(new_line)
+
+        dot2.add_updater(update_dot2)
+        line.add_updater(update_line)
+        dot.add_updater(update_dot)
+
+        vt.set_value(0)
+        self.play(vt.set_value,2, rate_func=linear, run_time=8)