Merge remote-tracking branch 'origin/eop' into eop

active_projects/eop/area_coin_toss.py

@@ -0,0 +1,65 @@
+from big_ol_pile_of_manim_imports import *
+from eop.pascal import *
+
+
+WIDTH = 6
+HEIGHT = 0.25
+COLOR_HEADS = YELLOW
+COLOR_TAILS = BLUE
+NB_ROWS = 28
+
+
+class AreaSplittingScene(Scene):
+
+    def create_rect_row(self,n):
+        rects_group = VGroup()
+        for k in range(n+1):
+            proportion = float(choose(n,k)) / 2**n
+            new_rect = Rectangle(
+                width = proportion * WIDTH, 
+                height = HEIGHT,
+                fill_color = graded_color(n,k),
+                fill_opacity = 1
+            )
+            new_rect.next_to(rects_group,RIGHT,buff = 0)
+            rects_group.add(new_rect)
+        return rects_group
+
+    def split_rect_row(self,rect_row):
+
+        split_row = VGroup()
+        for rect in rect_row.submobjects:
+            half = rect.copy().stretch_in_place(0.5,0)
+            left_half = half.next_to(rect.get_center(),LEFT,buff = 0)
+            right_half = half.copy().next_to(rect.get_center(),RIGHT,buff = 0)
+            split_row.add(left_half, right_half)
+        return split_row
+
+    def construct(self):
+
+        rect_row = self.create_rect_row(0)
+        rect_row.move_to(3.5*UP + 0*HEIGHT*DOWN)
+        self.add(rect_row)
+        for n in range(NB_ROWS):
+            # copy and shift
+            new_rect_row = rect_row.copy()
+            self.add(new_rect_row)
+            self.play(new_rect_row.shift,HEIGHT * DOWN)
+            self.wait()
+
+            #split
+            split_row = self.split_rect_row(new_rect_row)
+            self.play(FadeIn(split_row))
+            self.wait()
+
+            # merge
+            rect_row = self.create_rect_row(n+1)
+            rect_row.move_to(3.5*UP + (n+1)*HEIGHT*DOWN)
+            self.play(FadeIn(rect_row))
+            self.wait()
+
+
+
+
+
+