Files
manim/3b1b_projects/old/hyperdarts.py

2827 lines
80 KiB
Python

from manimlib.imports import *
OUTPUT_DIRECTORY = "hyperdarts"
BROWN_PAPER = "#958166"
class HyperdartScene(MovingCameraScene):
CONFIG = {
"square_width": 6,
"square_style": {
"stroke_width": 2,
"fill_color": BLUE,
"fill_opacity": 0.5,
},
"circle_style": {
"fill_color": RED_E,
"fill_opacity": 1,
"stroke_width": 0,
},
"circle_center_dot_radius": 0.025,
"default_line_style": {
"stroke_width": 2,
"stroke_color": WHITE,
},
"default_dot_config": {
"fill_color": WHITE,
"background_stroke_width": 1,
"background_stroke_color": BLACK,
"radius": 0.5 * DEFAULT_DOT_RADIUS,
},
"dart_sound": "dart_low",
"default_bullseye_shadow_opacity": 0.35,
}
def setup(self):
MovingCameraScene.setup(self)
self.square = self.get_square()
self.circle = self.get_circle()
self.circle_center_dot = self.get_circle_center_dot()
self.add(self.square)
self.add(self.circle)
self.add(self.circle_center_dot)
def get_square(self):
return Square(
side_length=self.square_width,
**self.square_style
)
def get_circle(self, square=None):
square = square or self.square
circle = Circle(**self.circle_style)
circle.replace(square)
return circle
def get_circle_center_dot(self, circle=None):
circle = circle or self.circle
return Dot(
circle.get_center(),
radius=self.circle_center_dot_radius,
fill_color=BLACK,
)
def get_number_plane(self):
square = self.square
unit_size = square.get_width() / 2
plane = NumberPlane(
axis_config={
"unit_size": unit_size,
}
)
plane.add_coordinates()
plane.shift(square.get_center() - plane.c2p(0, 0))
return plane
def get_random_points(self, n):
square = self.square
points = np.random.uniform(-1, 1, 3 * n).reshape((n, 3))
points[:, 0] *= square.get_width() / 2
points[:, 1] *= square.get_height() / 2
points[:, 2] = 0
points += square.get_center()
return points
def get_random_point(self):
return self.get_random_points(1)[0]
def get_dot(self, point):
return Dot(point, **self.default_dot_config)
# Hit transform rules
def is_inside(self, point, circle=None):
circle = circle or self.circle
return get_norm(point - circle.get_center()) <= circle.get_width() / 2
def get_new_radius(self, point, circle=None):
circle = circle or self.circle
center = circle.get_center()
radius = circle.get_width() / 2
p_dist = get_norm(point - center)
return np.sqrt(radius**2 - p_dist**2)
def get_hit_distance_line(self, point, circle=None):
circle = circle or self.circle
line = Line(
circle.get_center(), point,
**self.default_line_style
)
return line
def get_chord(self, point, circle=None):
circle = circle or self.circle
center = circle.get_center()
p_angle = angle_of_vector(point - center)
chord = Line(DOWN, UP)
new_radius = self.get_new_radius(point, circle)
chord.scale(new_radius)
chord.rotate(p_angle)
chord.move_to(point)
chord.set_style(**self.default_line_style)
return chord
def get_radii_to_chord(self, chord, circle=None):
circle = circle or self.circle
center = circle.get_center()
radii = VGroup(*[
DashedLine(center, point)
for point in chord.get_start_and_end()
])
radii.set_style(**self.default_line_style)
return radii
def get_all_hit_lines(self, point, circle=None):
h_line = self.get_hit_distance_line(point, circle)
chord = self.get_chord(point, circle)
# radii = self.get_radii_to_chord(chord, circle)
elbow = Elbow(width=0.15)
elbow.set_stroke(WHITE, 2)
elbow.rotate(h_line.get_angle() - PI, about_point=ORIGIN)
elbow.shift(point)
return VGroup(h_line, chord, elbow)
def get_dart(self, length=1.5):
dart = SVGMobject(file_name="dart")
dart.rotate(135 * DEGREES)
dart.set_width(length)
dart.rotate(45 * DEGREES, UP)
dart.rotate(-10 * DEGREES)
dart.set_fill(GREY)
dart.set_sheen(2, UL)
dart.set_stroke(BLACK, 0.5, background=True)
dart.set_stroke(width=0)
return dart
# New circle
def get_new_circle_from_point(self, point, circle=None):
return self.get_new_circle(
self.get_new_radius(point, circle),
circle,
)
def get_new_circle_from_chord(self, chord, circle=None):
return self.get_new_circle(
chord.get_length() / 2,
circle,
)
def get_new_circle(self, new_radius, circle=None):
circle = circle or self.circle
new_circle = self.get_circle()
new_circle.set_width(2 * new_radius)
new_circle.move_to(circle)
return new_circle
# Sound
def add_dart_sound(self, time_offset=0, gain=-20, **kwargs):
self.add_sound(
self.dart_sound,
time_offset=time_offset,
gain=-20,
**kwargs,
)
# Animations
def show_full_hit_process(self, point, pace="slow", with_dart=True):
assert(pace in ["slow", "fast"])
to_fade = VGroup()
if with_dart:
dart, dot = self.show_hit_with_dart(point)
to_fade.add(dart, dot)
else:
dot = self.show_hit(point)
to_fade.add(dot)
if pace == "slow":
self.wait(0.5)
# TODO, automatically act based on hit or miss?
lines = self.show_geometry(point, pace)
chord_and_shadow = self.show_circle_shrink(lines[1], pace=pace)
to_fade.add_to_back(chord_and_shadow, lines)
self.play(
FadeOut(to_fade),
run_time=(1 if pace == "slow" else 0.5)
)
def show_hits_with_darts(self, points, run_time=0.5, added_anims=None):
if added_anims is None:
added_anims = []
darts = VGroup(*[
self.get_dart().move_to(point, DR)
for point in points
])
dots = VGroup(*[
self.get_dot(point)
for point in points
])
for dart in darts:
dart.save_state()
dart.set_x(-(FRAME_WIDTH + dart.get_width()) / 2)
dart.rotate(20 * DEGREES)
n_points = len(points)
self.play(
ShowIncreasingSubsets(
dots,
rate_func=squish_rate_func(linear, 0.5, 1),
),
LaggedStart(*[
Restore(
dart,
path_arc=-20 * DEGREES,
rate_func=linear,
run_time=run_time,
)
for dart in darts
], lag_ratio=(1 / n_points)),
*added_anims,
run_time=run_time
)
for n in range(n_points):
self.add_dart_sound(
time_offset=(-n / (2 * n_points))
)
return darts, dots
def show_hit_with_dart(self, point, run_time=0.25, **kwargs):
darts, dots = self.show_hits_with_darts([point], run_time, **kwargs)
return darts[0], dots[0]
def show_hit(self, point, pace="slow", added_anims=None):
assert(pace in ["slow", "fast"])
if added_anims is None:
added_anims = []
dot = self.get_dot(point)
if pace == "slow":
self.play(
FadeInFromLarge(dot, rate_func=rush_into),
*added_anims,
run_time=0.5,
)
elif pace == "fast":
self.add(dot)
# self.add_dart_sound()
return dot
def show_geometry(self, point, pace="slow"):
assert(pace in ["slow", "fast"])
lines = self.get_all_hit_lines(point, self.circle)
h_line, chord, elbow = lines
# Note, note animating radii anymore...does that mess anything up?
if pace == "slow":
self.play(
ShowCreation(h_line),
GrowFromCenter(chord),
)
self.play(ShowCreation(elbow))
elif pace == "fast":
self.play(
ShowCreation(h_line),
GrowFromCenter(chord),
ShowCreation(elbow),
run_time=0.5
)
# return VGroup(h_line, chord)
return lines
def show_circle_shrink(self, chord, pace="slow", shadow_opacity=None):
circle = self.circle
chord_copy = chord.copy()
new_circle = self.get_new_circle_from_chord(chord)
to_fade = VGroup(chord_copy)
if shadow_opacity is None:
shadow_opacity = self.default_bullseye_shadow_opacity
if shadow_opacity > 0:
shadow = circle.copy()
shadow.set_opacity(shadow_opacity)
to_fade.add_to_back(shadow)
if circle in self.mobjects:
index = self.mobjects.index(circle)
self.mobjects.insert(index, shadow)
else:
self.add(shadow, self.circle_center_dot)
outline = VGroup(*[
VMobject().pointwise_become_partial(new_circle, a, b)
for (a, b) in [(0, 0.5), (0.5, 1)]
])
outline.rotate(chord.get_angle())
outline.set_fill(opacity=0)
outline.set_stroke(YELLOW, 2)
assert(pace in ["slow", "fast"])
if pace == "slow":
self.play(
chord_copy.move_to, circle.get_center(),
circle.set_opacity, 0.5,
)
self.play(
Rotating(
chord_copy,
radians=PI,
),
ShowCreation(
outline,
lag_ratio=0
),
run_time=1,
rate_func=smooth,
)
self.play(
Transform(circle, new_circle),
FadeOut(outline),
)
elif pace == "fast":
outline = new_circle.copy()
outline.set_fill(opacity=0)
outline.set_stroke(YELLOW, 2)
outline.move_to(chord)
outline.generate_target()
outline.target.move_to(circle)
self.play(
chord_copy.move_to, circle,
Transform(circle, new_circle),
# MoveToTarget(
# outline,
# remover=True
# )
)
# circle.become(new_circle)
# circle.become(new_circle)
# self.remove(new_circle)
return to_fade
def show_miss(self, point, with_dart=True):
square = self.square
miss = TextMobject("Miss!")
miss.next_to(point, UP)
to_fade = VGroup(miss)
if with_dart:
dart, dot = self.show_hit_with_dart(point)
to_fade.add(dart, dot)
else:
dot = self.show_hit(point)
to_fade.add(dot)
self.play(
ApplyMethod(
square.set_color, YELLOW,
rate_func=lambda t: (1 - t),
),
GrowFromCenter(miss),
run_time=0.25
)
return to_fade
def show_game_over(self):
game_over = TextMobject("GAME OVER")
game_over.set_width(FRAME_WIDTH - 1)
rect = FullScreenFadeRectangle(opacity=0.25)
self.play(
FadeIn(rect),
FadeInFromLarge(game_over),
)
return VGroup(rect, game_over)
class Dartboard(VGroup):
CONFIG = {
"radius": 3,
"n_sectors": 20,
}
def __init__(self, **kwargs):
super().__init__(**kwargs)
n_sectors = self.n_sectors
angle = TAU / n_sectors
segments = VGroup(*[
VGroup(*[
AnnularSector(
inner_radius=in_r,
outer_radius=out_r,
start_angle=n * angle,
angle=angle,
color=color,
)
for n, color in zip(
range(n_sectors),
it.cycle(colors)
)
])
for colors, in_r, out_r in [
([LIGHT_GREY, DARKER_GREY], 0, 1),
([GREEN_E, RED_E], 0.5, 0.55),
([GREEN_E, RED_E], 0.95, 1),
]
])
segments.rotate(-angle / 2)
bullseyes = VGroup(*[
Circle(radius=r)
for r in [0.07, 0.035]
])
bullseyes.set_fill(opacity=1)
bullseyes.set_stroke(width=0)
bullseyes[0].set_color(GREEN_E)
bullseyes[1].set_color(RED_E)
self.bullseye = bullseyes[1]
self.add(*segments, *bullseyes)
self.scale(self.radius)
# Scenes to overlay on Numerphile
class TableOfContents(Scene):
def construct(self):
rect = FullScreenFadeRectangle(opacity=0.75)
self.add(rect)
parts = VGroup(
TextMobject("The game"),
TextMobject("The puzzle"),
TextMobject("The micropuzzles"),
TextMobject("The answer"),
)
parts.scale(1.5)
parts.arrange(DOWN, buff=LARGE_BUFF, aligned_edge=LEFT)
parts.to_edge(LEFT, buff=2)
parts.set_opacity(0.5)
self.add(parts)
for part in parts:
dot = Dot()
dot.next_to(part, LEFT, SMALL_BUFF)
dot.match_style(part)
self.add(dot)
last_part = VMobject()
last_part.save_state()
for part in parts:
part.save_state()
self.play(
part.scale, 1.5, {"about_edge": LEFT},
part.set_opacity, 1,
Restore(last_part)
)
self.wait()
last_part = part
class ShowGiantBullseye(HyperdartScene):
def construct(self):
square = self.square
circle = self.circle
self.remove(square, circle)
board = Dartboard()
board.replace(circle)
bullseye = board.bullseye
bullseye_border = bullseye.copy()
bullseye_border.set_fill(opacity=0)
bullseye_border.set_stroke(YELLOW, 3)
self.add(board)
# Label
label = TextMobject("``", "Bullseye", "''")
label.scale(1.5)
label.next_to(square, LEFT, aligned_edge=UP)
label.set_color(RED)
arrow = Arrow(
label.get_bottom(),
bullseye.get_corner(DR)
)
self.play(
FadeInFromDown(label[1]),
ShowCreation(arrow),
)
self.play(
bullseye.match_width, board,
ApplyMethod(
arrow.scale, 0.4,
{"about_point": arrow.get_start()}
),
run_time=2,
)
self.play(Write(label[::2]))
self.wait()
class ShowExampleHit(HyperdartScene):
def construct(self):
square = self.square
circle = self.circle
circle.set_fill(BROWN_PAPER, opacity=0.95)
old_board = VGroup(square, circle)
self.remove(square)
board = Dartboard()
board.replace(old_board)
self.add(board, circle)
# Show hit
point = 0.75 * UP
dart, dot = self.show_hit_with_dart(point)
# Draw lines (with labels)
lines = self.get_all_hit_lines(point)
h_line, chord, elbow = lines
h_label = TexMobject("h")
h_label.next_to(h_line, LEFT, SMALL_BUFF)
chord_word = TextMobject("Chord")
chord_word.next_to(chord.get_center(), UR, SMALL_BUFF)
self.add(h_line, dot)
self.play(ShowCreation(h_line))
self.play(Write(h_label))
self.wait()
self.play(
ShowCreation(chord),
ShowCreation(elbow),
Write(chord_word, run_time=1)
)
self.wait()
# Show shrinkage
chord_copy = chord.copy()
chord_copy.move_to(ORIGIN)
new_circle = circle.copy()
new_circle.set_fill(RED, 1)
new_circle.match_width(chord_copy)
new_circle.move_to(ORIGIN)
new_diam_word = TextMobject("New diameter")
new_diam_word.next_to(chord_copy, DOWN, SMALL_BUFF)
outline = VGroup(
Arc(start_angle=0, angle=PI),
Arc(start_angle=PI, angle=PI),
)
outline.set_stroke(YELLOW, 3)
outline.set_fill(opacity=0)
outline.replace(new_circle)
self.play(
circle.set_color, DARK_GREY,
TransformFromCopy(chord, chord_copy),
FadeInFrom(new_diam_word, UP)
)
self.play(
Rotate(chord_copy, PI),
ShowCreation(outline, lag_ratio=0),
)
self.play()
# Show variable hit_point
self.remove(lines)
point_tracker = VectorizedPoint(point)
self.remove(lines, *lines)
lines = always_redraw(
lambda: self.get_all_hit_lines(point_tracker.get_location())
)
dot.add_updater(lambda m: m.move_to(point_tracker))
dart.add_updater(lambda m: m.move_to(point_tracker, DR))
chord_copy.add_updater(
lambda m: m.match_width(lines[1]).move_to(ORIGIN)
)
new_circle.add_updater(lambda m: m.match_width(chord_copy).move_to(ORIGIN))
h_label.add_updater(lambda m: m.next_to(lines[0], LEFT, SMALL_BUFF))
chord_word.add_updater(lambda m: m.next_to(lines[1].get_center(), UR, SMALL_BUFF))
ndw_width = new_diam_word.get_width()
new_diam_word.add_updater(
lambda m: m.set_width(
min(ndw_width, chord_copy.get_width())
).next_to(chord_copy, DOWN, SMALL_BUFF)
)
self.add(new_circle, chord_copy, lines, h_label, dart, dot, chord_word, new_diam_word)
self.play(
FadeOut(outline),
FadeIn(new_circle)
)
self.wait()
self.play(
point_tracker.shift, 2.1 * UP,
run_time=9,
rate_func=there_and_back_with_pause,
)
class QuicklyAnimatedShrinking(HyperdartScene):
def construct(self):
# square = self.square
# circle = self.circle
for x in range(5):
point = self.get_random_point()
while not self.is_inside(point):
point = self.get_random_point()
self.show_full_hit_process(point, pace="fast")
# self.show_game_over()
class SimulateRealGame(HyperdartScene):
CONFIG = {
"circle_style": {
# "fill_color": BROWN_PAPER,
}
}
def construct(self):
board = Dartboard()
board.set_opacity(0.5)
self.remove(self.square)
self.square.set_opacity(0)
self.add(board, self.circle)
points = [
0.5 * UP,
2.0 * UP,
1.9 * LEFT + 0.4 * DOWN,
]
for point in points:
self.show_full_hit_process(point)
self.show_miss(1.8 * DL)
self.show_game_over()
class GameOver(HyperdartScene):
def construct(self):
self.clear()
self.show_game_over()
class SquareAroundTheDartBoard(HyperdartScene):
def construct(self):
square = self.square
circle = self.circle
VGroup(square, circle).to_edge(DOWN, MED_SMALL_BUFF)
self.clear()
board = Dartboard()
board.replace(square)
title = TextMobject("Square around the dart board")
title.scale(1.5)
title.next_to(square, UP, MED_LARGE_BUFF)
self.add(board)
self.play(FadeInFromDown(title))
self.add(square, board)
self.play(DrawBorderThenFill(square, run_time=2))
self.wait()
class ContrastDistributions(HyperdartScene):
def construct(self):
square = self.square
circle = self.circle
board = Dartboard()
board.replace(circle)
group = VGroup(square, circle, board)
group.to_edge(LEFT)
group.scale(0.8, about_edge=DOWN)
group_copy = group.copy()
square_copy, circle_copy, board_copy = group_copy
group_copy.set_x(-group.get_center()[0])
v_line = DashedLine(FRAME_HEIGHT * UP / 2, FRAME_HEIGHT * DOWN / 2)
left_label = TextMobject("Our distribution\\\\(uniform in the square)")
left_label.match_x(group)
left_label.to_edge(UP)
right_label = TextMobject("More realistic distribution")
right_label.match_x(group_copy)
right_label.to_edge(UP)
n_points = 2000
left_points = self.get_random_points(n_points)
right_points = np.random.multivariate_normal(
mean=board_copy.get_center(),
cov=0.6 * np.identity(3),
size=n_points
)
left_dots, right_dots = [
VGroup(*[
Dot(p, radius=0.02) for p in points
])
for points in [left_points, right_points]
]
left_rect = FullScreenFadeRectangle(opacity=0.75)
left_rect.stretch(0.49, 0, about_edge=LEFT)
right_rect = left_rect.copy()
right_rect.to_edge(RIGHT, buff=0)
self.add(group, board_copy)
self.add(left_label, right_label)
self.add(v_line)
self.add(left_rect)
self.play(
LaggedStartMap(FadeInFromLarge, right_dots),
run_time=5
)
self.wait()
self.play(
FadeOut(left_rect),
FadeIn(right_rect),
)
self.play(
LaggedStartMap(FadeInFromLarge, left_dots),
run_time=5
)
self.wait()
class ChooseXThenYUniformly(Scene):
def construct(self):
# Setup
unit_size = 3
axes = Axes(
x_min=-1.25,
x_max=1.25,
y_min=-1.25,
y_max=1.25,
number_line_config={
"tick_frequency": 0.25,
"unit_size": unit_size,
},
)
numbers = [-1, -0.5, 0.5, 1]
num_config = {
"num_decimal_places": 1,
"background_stroke_width": 3,
}
axes.x_axis.add_numbers(
*numbers,
number_config=num_config,
)
axes.y_axis.add_numbers(
*numbers,
number_config=num_config,
direction=LEFT,
)
circle = Circle(radius=unit_size)
circle.set_stroke(WHITE, 0)
circle.set_fill(RED, 0.7)
square = Square()
square.replace(circle)
square.set_stroke(LIGHT_GREY, 1)
square = DashedVMobject(square, num_dashes=101)
self.add(square, circle)
self.add(axes)
# x and y stuff
x_tracker = ValueTracker(-1)
y_tracker = ValueTracker(-1)
get_x = x_tracker.get_value
get_y = y_tracker.get_value
x_tip = ArrowTip(start_angle=PI / 2, color=BLUE)
y_tip = ArrowTip(start_angle=0, color=YELLOW)
for tip in [x_tip, y_tip]:
tip.scale(0.5)
x_tip.add_updater(lambda m: m.move_to(axes.c2p(get_x(), 0), UP))
y_tip.add_updater(lambda m: m.move_to(axes.c2p(0, get_y()), RIGHT))
x_eq = VGroup(TexMobject("x = "), DecimalNumber(0))
x_eq.arrange(RIGHT, SMALL_BUFF)
x_eq[1].match_y(x_eq[0][0][1])
x_eq[1].add_updater(lambda m: m.set_value(get_x()))
x_eq.match_color(x_tip)
y_eq = VGroup(TexMobject("y = "), DecimalNumber(0))
y_eq.arrange(RIGHT, SMALL_BUFF)
y_eq[1].match_y(y_eq[0][0][1])
y_eq[1].add_updater(lambda m: m.set_value(get_y()))
y_eq.match_color(y_tip)
eqs = VGroup(x_eq, y_eq)
eqs.arrange(DOWN, buff=MED_LARGE_BUFF)
eqs.to_edge(UR)
self.add(x_tip)
self.add(x_eq)
# Choose x
self.play(
x_tracker.set_value, 1,
run_time=2,
)
self.play(
x_tracker.set_value, np.random.random(),
run_time=1,
)
# Choose y
self.play(
FadeIn(y_tip),
FadeIn(y_eq),
)
self.play(
y_tracker.set_value, 1,
run_time=2,
)
self.play(
y_tracker.set_value, np.random.random(),
run_time=1,
)
point = axes.c2p(get_x(), get_y())
dot = Dot(point)
x_line = DashedLine(axes.c2p(0, get_y()), point)
y_line = DashedLine(axes.c2p(get_x(), 0), point)
lines = VGroup(x_line, y_line)
lines.set_stroke(WHITE, 2)
self.play(*map(ShowCreation, lines))
self.play(DrawBorderThenFill(dot))
self.wait()
points = [
axes.c2p(*np.random.uniform(-1, 1, size=2))
for n in range(2000)
]
dots = VGroup(*[
Dot(point, radius=0.02)
for point in points
])
self.play(
LaggedStartMap(FadeInFromLarge, dots),
run_time=3,
)
self.wait()
class ShowDistributionOfScores(Scene):
CONFIG = {
"axes_config": {
"x_min": -1,
"x_max": 10,
"x_axis_config": {
"unit_size": 1.2,
"tick_frequency": 1,
},
"y_min": 0,
"y_max": 100,
"y_axis_config": {
"unit_size": 0.065,
"tick_frequency": 10,
"include_tip": False,
},
},
"random_seed": 1,
}
def construct(self):
# Add axes
axes = self.get_axes()
self.add(axes)
# setup scores
n_scores = 10000
scores = np.array([self.get_random_score() for x in range(n_scores)])
index_tracker = ValueTracker(n_scores)
def get_index():
value = np.clip(index_tracker.get_value(), 0, n_scores - 1)
return int(value)
# Setup histogram
bars = self.get_histogram_bars(axes)
bars.add_updater(
lambda b: self.set_histogram_bars(
b, scores[:get_index()], axes
)
)
self.add(bars)
# Add score label
score_label = VGroup(
TextMobject("Last score: "),
Integer(1)
)
score_label.scale(1.5)
score_label.arrange(RIGHT)
score_label[1].align_to(score_label[0][0][-1], DOWN)
score_label[1].add_updater(
lambda m: m.set_value(scores[get_index() - 1])
)
score_label[1].add_updater(
lambda m: m.set_fill(bars[scores[get_index() - 1]].get_fill_color())
)
n_trials_label = VGroup(
TextMobject("\\# Games: "),
Integer(0),
)
n_trials_label.scale(1.5)
n_trials_label.arrange(RIGHT, aligned_edge=UP)
n_trials_label[1].add_updater(
lambda m: m.set_value(get_index())
)
n_trials_label.to_corner(UR, buff=LARGE_BUFF)
score_label.next_to(
n_trials_label, DOWN,
buff=LARGE_BUFF,
aligned_edge=LEFT,
)
self.add(score_label)
self.add(n_trials_label)
# Add curr_score_arrow
curr_score_arrow = Arrow(0.25 * UP, ORIGIN, buff=0)
curr_score_arrow.set_stroke(WHITE, 5)
curr_score_arrow.add_updater(
lambda m: m.next_to(bars[scores[get_index() - 1] - 1], UP, SMALL_BUFF)
)
self.add(curr_score_arrow)
# Add mean bar
mean_line = DashedLine(ORIGIN, 4 * UP)
mean_line.set_stroke(YELLOW, 2)
def get_mean():
return np.mean(scores[:get_index()])
mean_line.add_updater(
lambda m: m.move_to(axes.c2p(get_mean(), 0), DOWN)
)
mean_label = VGroup(
TextMobject("Mean = "),
DecimalNumber(num_decimal_places=3),
)
mean_label.arrange(RIGHT)
mean_label.match_color(mean_line)
mean_label.add_updater(lambda m: m.next_to(mean_line, UP, SMALL_BUFF))
mean_label[1].add_updater(lambda m: m.set_value(get_mean()))
# Show many runs
index_tracker.set_value(1)
for value in [10, 100, 1000, 10000]:
anims = [
ApplyMethod(
index_tracker.set_value, value,
rate_func=linear,
run_time=5,
),
]
if value == 10:
anims.append(
FadeIn(
VGroup(mean_line, mean_label),
rate_func=squish_rate_func(smooth, 0.5, 1),
run_time=2,
),
)
self.play(*anims)
self.wait()
#
def get_axes(self):
axes = Axes(**self.axes_config)
axes.to_corner(DL)
axes.x_axis.add_numbers(*range(1, 12))
axes.y_axis.add_numbers(
*range(20, 120, 20),
number_config={
"unit": "\\%"
}
)
x_label = TextMobject("Score")
x_label.next_to(axes.x_axis.get_right(), UR, buff=0.5)
x_label.shift_onto_screen()
axes.x_axis.add(x_label)
y_label = TextMobject("Relative proportion")
y_label.next_to(axes.y_axis.get_top(), RIGHT, buff=0.75)
y_label.to_edge(UP, buff=MED_SMALL_BUFF)
axes.y_axis.add(y_label)
return axes
def get_histogram_bars(self, axes):
bars = VGroup()
for x in range(1, 10):
bar = Rectangle(width=axes.x_axis.unit_size)
bar.move_to(axes.c2p(x, 0), DOWN)
bar.x = x
bars.add(bar)
bars.set_fill(opacity=0.7)
bars.set_color_by_gradient(BLUE, YELLOW, RED)
bars.set_stroke(WHITE, 1)
return bars
def get_relative_proportion_map(self, all_scores):
scores = set(all_scores)
n_scores = len(all_scores)
return dict([
(s, np.sum(all_scores == s) / n_scores)
for s in set(scores)
])
def set_histogram_bars(self, bars, scores, axes):
prop_map = self.get_relative_proportion_map(scores)
epsilon = 1e-6
for bar in bars:
prop = prop_map.get(bar.x, epsilon)
bar.set_height(
prop * axes.y_axis.unit_size * 100,
stretch=True,
about_edge=DOWN,
)
def get_random_score(self):
score = 1
radius = 1
while True:
point = np.random.uniform(-1, 1, size=2)
hit_radius = get_norm(point)
if hit_radius > radius:
return score
else:
score += 1
radius = np.sqrt(radius**2 - hit_radius**2)
class ExactBullseye(HyperdartScene):
def construct(self):
board = Dartboard()
board.replace(self.square)
lines = VGroup(Line(DOWN, UP), Line(LEFT, RIGHT))
lines.set_stroke(WHITE, 1)
lines.replace(self.square)
self.add(board, lines)
dart, dot = self.show_hit_with_dart(0.0037 * DOWN)
self.play(FadeOut(dot))
frame = self.camera_frame
self.play(frame.scale, 0.02, run_time=5)
self.wait()
class ShowProbabilityForFirstShot(HyperdartScene):
def construct(self):
square = self.square
circle = self.circle
VGroup(square, circle).to_edge(LEFT)
r_line = DashedLine(circle.get_center(), circle.get_right())
r_label = TexMobject("r = 1")
r_label.next_to(r_line, DOWN, SMALL_BUFF)
self.add(r_line, r_label)
points = self.get_random_points(3000)
dots = VGroup(*[Dot(point, radius=0.02) for point in points])
dots.set_fill(WHITE, 0.5)
p_label = TexMobject("P", "(S > 1)", "= ")
square_frac = VGroup(
circle.copy().set_height(0.5),
Line(LEFT, RIGHT).set_width(0.7),
square.copy().set_height(0.5).set_stroke(width=0)
)
square_frac.arrange(DOWN, buff=SMALL_BUFF)
result = TexMobject("=", "{\\pi \\over 4}")
equation = VGroup(p_label, square_frac, result)
equation.arrange(RIGHT)
equation.scale(1.4)
equation.to_edge(RIGHT, buff=MED_LARGE_BUFF)
brace = Brace(p_label[1], UP, buff=SMALL_BUFF)
brace_label = brace.get_text("At least one\\\\``bullseye''")
self.add(equation, brace, brace_label)
self.play(
LaggedStartMap(FadeInFromLarge, dots),
run_time=5,
)
self.play(
ReplacementTransform(
circle.copy().set_fill(opacity=0).set_stroke(WHITE, 1),
square_frac[0]
),
)
self.play(
ReplacementTransform(
square.copy().set_fill(opacity=0),
square_frac[2]
),
)
self.wait(2)
# Dar on the line
x = np.random.random()
y = np.sqrt(1 - x**2)
unit = circle.get_width() / 2
point = circle.get_center() + unit * x * RIGHT + unit * y * UP
point += 0.004 * DOWN
frame = self.camera_frame
dart, dot = self.show_hit_with_dart(point)
self.remove(dot)
self.play(
frame.scale, 0.05,
frame.move_to, point,
run_time=5,
)
class SamplingFourRandomNumbers(Scene):
CONFIG = {
"n_terms": 4,
"title_tex": "P\\left(x_0{}^2 + y_0{}^2 + x_1{}^2 + y_1{}^2 < 1\\right) = \\, ???",
"nl_to_nl_buff": 0.75,
"to_floor_buff": 0.5,
"tip_scale_factor": 0.75,
"include_half_labels": True,
"include_title": True,
}
def construct(self):
texs = ["x_0", "y_0", "x_1", "y_1", "x_2", "y_2"][:self.n_terms]
colors = [BLUE, YELLOW, BLUE_B, YELLOW_B, BLUE_A, YELLOW_A][:self.n_terms]
t2c = dict([(t, c) for t, c in zip(texs, colors)])
# Title
if self.include_title:
title = TexMobject(
self.title_tex,
tex_to_color_map=t2c
)
title.scale(1.5)
title.to_edge(UP)
h_line = DashedLine(title.get_left(), title.get_right())
h_line.next_to(title, DOWN, MED_SMALL_BUFF)
self.add(title, h_line)
# Number lines
number_lines = VGroup(*[
NumberLine(
x_min=-1,
x_max=1,
tick_frequency=0.25,
unit_size=3,
)
for x in range(self.n_terms)
])
for line in number_lines:
line.add_numbers(-1, 0, 1)
if self.include_half_labels:
line.add_numbers(
-0.5, 0.5,
number_config={"num_decimal_places": 1},
)
number_lines.arrange(DOWN, buff=self.nl_to_nl_buff)
number_lines.to_edge(LEFT, buff=0.5)
number_lines.to_edge(DOWN, buff=self.to_floor_buff)
self.add(number_lines)
# Trackers
trackers = Group(*[ValueTracker(0) for x in range(self.n_terms)])
tips = VGroup(*[
ArrowTip(
start_angle=-PI / 2,
color=color
).scale(self.tip_scale_factor)
for color in colors
])
labels = VGroup(*[
TexMobject(tex)
for tex in texs
])
for tip, tracker, line, label in zip(tips, trackers, number_lines, labels):
tip.line = line
tip.tracker = tracker
tip.add_updater(lambda t: t.move_to(
t.line.n2p(t.tracker.get_value()), DOWN
))
label.tip = tip
label.match_color(tip)
label.arrange(RIGHT, buff=MED_SMALL_BUFF)
label.add_updater(lambda l: l.next_to(l.tip, UP, SMALL_BUFF))
# label.add_updater(lambda l: l[1].set_value(l.tip.tracker.get_value()))
self.add(tips, labels)
# Write bit sum
summands = VGroup(*[
TexMobject("\\big(", "+0.00", "\\big)^2").set_color(color)
for color in colors
])
summands.arrange(DOWN)
summands.to_edge(RIGHT, buff=3)
for summand, tracker in zip(summands, trackers):
dec = DecimalNumber(include_sign=True)
dec.match_color(summand)
dec.tracker = tracker
dec.add_updater(lambda d: d.set_value(d.tracker.get_value()))
dec.move_to(summand[1])
summand.submobjects[1] = dec
h_line = Line(LEFT, RIGHT)
h_line.set_width(3)
h_line.next_to(summands, DOWN, aligned_edge=RIGHT)
plus = TexMobject("+")
plus.next_to(h_line.get_left(), UR)
h_line.add(plus)
total = DecimalNumber()
total.scale(1.5)
total.next_to(h_line, DOWN)
total.match_x(summands)
total.add_updater(lambda d: d.set_value(np.sum([
t.get_value()**2 for t in trackers
])))
VGroup(summands, h_line, total).shift_onto_screen()
self.add(summands, h_line, total)
# < or > 1
lt, gt = signs = VGroup(
TexMobject("< 1 \\quad \\checkmark"),
TexMobject("\\ge 1 \\quad"),
)
for sign in signs:
sign.scale(1.5)
sign.next_to(total, RIGHT, MED_LARGE_BUFF)
lt.set_color(GREEN)
gt.set_color(RED)
def update_signs(signs):
i = int(total.get_value() > 1)
signs[1 - i].set_opacity(0)
signs[i].set_opacity(1)
signs.add_updater(update_signs)
self.add(signs)
# Run simulation
for x in range(9):
trackers.generate_target()
for t in trackers.target:
t.set_value(np.random.uniform(-1, 1))
if x == 8:
for t in trackers.target:
t.set_value(np.random.uniform(-0.5, 0.5))
self.remove(signs)
self.play(MoveToTarget(trackers))
self.add(signs)
self.wait()
# Less than 0.5
nl = number_lines[0]
line = Line(nl.n2p(-0.5), nl.n2p(0.5))
rect = Rectangle(height=0.25)
rect.set_stroke(width=0)
rect.set_fill(GREEN, 0.5)
rect.match_width(line, stretch=True)
rects = VGroup(*[
rect.copy().move_to(line.n2p(0))
for line in number_lines
])
self.play(LaggedStartMap(GrowFromCenter, rects))
self.wait()
self.play(LaggedStartMap(FadeOut, rects))
# Set one to 0.5
self.play(trackers[0].set_value, 0.9)
self.play(ShowCreationThenFadeAround(summands[0]))
self.wait()
self.play(LaggedStart(*[
ShowCreationThenFadeAround(summand)
for summand in summands[1:]
]))
self.play(*[
ApplyMethod(tracker.set_value, 0.1)
for tracker in trackers[1:]
])
self.wait(10)
class SamplingTwoRandomNumbers(SamplingFourRandomNumbers):
CONFIG = {
"n_terms": 2,
"title_tex": "P\\left(x_0{}^2 + y_0{}^2 < 1\\right) = \\, ???",
"nl_to_nl_buff": 1,
"to_floor_buff": 2,
"random_seed": 1,
}
class SamplingSixRandomNumbers(SamplingFourRandomNumbers):
CONFIG = {
"n_terms": 6,
"nl_to_nl_buff": 0.5,
"include_half_labels": False,
"include_title": False,
"tip_scale_factor": 0.5,
}
class SamplePointIn3d(SpecialThreeDScene):
def construct(self):
axes = self.axes = self.get_axes()
sphere = self.get_sphere()
sphere.set_fill(BLUE_E, 0.25)
sphere.set_stroke(opacity=0.5)
cube = Cube()
cube.replace(sphere)
cube.set_fill(GREY, 0.2)
cube.set_stroke(WHITE, 1, opacity=0.5)
self.set_camera_orientation(
phi=80 * DEGREES,
theta=-120 * DEGREES,
)
self.begin_ambient_camera_rotation(rate=0.03)
dot = Sphere()
# dot = Dot()
dot.set_shade_in_3d(True)
dot.set_width(0.1)
dot.move_to(axes.c2p(*np.random.uniform(0, 1, size=3)))
lines = always_redraw(lambda: self.get_lines(dot.get_center()))
labels = always_redraw(lambda: self.get_labels(lines))
self.add(axes)
self.add(cube)
for line, label in zip(lines, labels):
self.play(
ShowCreation(line),
FadeIn(label)
)
self.add(lines, labels)
self.play(GrowFromCenter(dot))
self.play(DrawBorderThenFill(sphere, stroke_width=1))
self.wait(2)
n_points = 3000
points = [
axes.c2p(*np.random.uniform(-1, 1, 3))
for x in range(n_points)
]
# point_cloud = PMobject().add_points(points)
dots = VGroup(*[
Dot(
point,
radius=0.01,
shade_in_3d=True,
)
for point in points
])
dots.set_stroke(WHITE, 2)
dots.set_opacity(0.5)
self.play(ShowIncreasingSubsets(dots, run_time=9))
# self.play(ShowCreation(point_cloud, run_time=3))
self.wait(4)
return
for x in range(6):
self.play(
point.move_to,
axes.c2p(*np.random.uniform(-1, 1, size=3))
)
self.wait(2)
self.wait(7)
def get_lines(self, point):
axes = self.axes
x, y, z = axes.p2c(point)
p0 = axes.c2p(0, 0, 0)
p1 = axes.c2p(x, 0, 0)
p2 = axes.c2p(x, y, 0)
p3 = axes.c2p(x, y, z)
x_line = DashedLine(p0, p1, color=GREEN)
y_line = DashedLine(p1, p2, color=RED)
z_line = DashedLine(p2, p3, color=BLUE)
lines = VGroup(x_line, y_line, z_line)
lines.set_shade_in_3d(True)
return lines
def get_labels(self, lines):
x_label = TexMobject("x")
y_label = TexMobject("y")
z_label = TexMobject("z")
result = VGroup(x_label, y_label, z_label)
result.rotate(90 * DEGREES, RIGHT)
result.set_shade_in_3d(True)
x_line, y_line, z_line = lines
x_label.match_color(x_line)
y_label.match_color(y_line)
z_label.match_color(z_line)
x_label.next_to(x_line, IN, SMALL_BUFF)
y_label.next_to(y_line, RIGHT + OUT, SMALL_BUFF)
z_label.next_to(z_line, RIGHT, SMALL_BUFF)
return result
class OverlayToPointIn3d(Scene):
def construct(self):
t2c = {
"{x}": GREEN,
"{y}": RED,
"{z}": BLUE,
}
ineq = TexMobject(
"{x}^2 + {y}^2 + {z}^2 < 1",
tex_to_color_map=t2c,
)
ineq.scale(1.5)
ineq.move_to(FRAME_WIDTH * LEFT / 4)
ineq.to_edge(UP)
equiv = TexMobject("\\Leftrightarrow")
equiv.scale(2)
equiv.match_y(ineq)
rhs = TextMobject(
"$({x}, {y}, {z})$",
" lies within a\\\\sphere with radius 1"
)
rhs[0][1].set_color(GREEN)
rhs[0][3].set_color(RED)
rhs[0][5].set_color(BLUE)
rhs.scale(1.3)
rhs.next_to(equiv, RIGHT)
rhs.to_edge(UP)
self.add(ineq)
self.wait()
self.play(Write(equiv))
self.wait()
self.play(FadeIn(rhs))
self.wait()
class TwoDPlusTwoDEqualsFourD(HyperdartScene):
def construct(self):
board = VGroup(*self.mobjects)
unit_size = 1.5
axes = Axes(
x_min=-1.25,
x_max=1.25,
y_min=-1.25,
y_max=1.25,
number_line_config={
"unit_size": unit_size,
"tick_frequency": 0.5,
"include_tip": False,
}
)
board.set_height(2 * unit_size)
axes.move_to(board)
axes.set_stroke(width=1)
board.add(axes)
board.to_edge(LEFT)
self.add(board)
# Set up titles
kw = {
"tex_to_color_map": {
"x_0": WHITE,
"y_0": WHITE,
"x_1": WHITE,
"y_1": WHITE,
}
}
title1 = VGroup(
TextMobject("First shot"),
TexMobject("(x_0, y_0)", **kw),
)
title2 = VGroup(
TextMobject("Second shot"),
TexMobject("(x_1, y_1)", **kw),
)
title3 = VGroup(
TextMobject("Point in 4d space"),
TexMobject("(x_0, y_0, x_1, y_1)", **kw)
)
titles = VGroup(title1, title2, title3)
for title in titles:
title.arrange(DOWN)
plus = TexMobject("+").scale(2)
equals = TexMobject("=").scale(2)
label1 = TexMobject("(x_0, y_0)")
label2 = TexMobject("(x_1, y_1)")
VGroup(label1, label2).scale(0.8)
title1.next_to(board, UP)
# First hit
point1 = axes.c2p(0.5, 0.7)
dart1, dot1 = self.show_hit_with_dart(point1)
label1.next_to(dot1, UR, buff=0)
self.add(title1, label1)
# lines1 = self.show_geometry(point1, pace="fast")
# chord_and_shadow1 = self.show_circle_shrink(lines1[1], pace="fast")
board_copy = board.copy()
board_copy.next_to(board, RIGHT, buff=LARGE_BUFF)
self.square = board_copy[0]
title2.next_to(board_copy, UP)
plus.move_to(titles[:2])
self.play(ReplacementTransform(board.copy().fade(1), board_copy))
point2 = self.get_random_point()
dart2, dot2 = self.show_hit_with_dart(point2)
label2.next_to(dot2, UR, buff=0)
self.add(plus, title2, label2)
self.wait()
# Set up the other titles
title3.to_edge(RIGHT)
title3.match_y(title2)
equals.move_to(midpoint(title2.get_right(), title3.get_left()))
randy = Randolph(height=2.5)
randy.next_to(title3, DOWN, buff=LARGE_BUFF)
randy.look_at(title3)
kw = {"path_arc": -20 * DEGREES}
self.play(
LaggedStart(
*[
TransformFromCopy(
title1[1].get_part_by_tex(tex),
title3[1].get_part_by_tex(tex),
**kw
)
for tex in ["(", "x_0", ",", "y_0"]
],
*[
TransformFromCopy(
title2[1].get_part_by_tex(tex),
title3[1].get_parts_by_tex(tex)[-1],
**kw
)
for tex in ["x_1", ",", "y_1", ")"]
],
TransformFromCopy(
title2[1].get_part_by_tex(","),
title3[1].get_parts_by_tex(",")[1],
**kw
),
lag_ratio=0.01,
),
Write(equals),
)
self.play(
FadeInFromDown(title3[0]),
FadeIn(randy),
)
self.play(randy.change, "horrified")
self.play(Blink(randy))
self.wait()
self.play(randy.change, "confused")
self.play(Blink(randy))
self.wait()
class ExpectedValueComputation(Scene):
def construct(self):
t2c = {
"0": MAROON_C,
"1": BLUE,
"2": GREEN,
"3": YELLOW,
"4": RED,
}
line1 = TexMobject(
"E[S]", "=",
"1 \\cdot", "P(S = 1)", "+",
"2 \\cdot", "P(S = 2)", "+",
"3 \\cdot", "P(S = 3)", "+",
"\\cdots",
tex_to_color_map=t2c
)
line2 = TexMobject(
"=&\\phantom{-}",
"1 \\cdot", "\\big(", "P(S > 0)", "-", "P(S > 1)", "\\big)", "\\\\&+",
"2 \\cdot", "\\big(", "P(S > 1)", "-", "P(S > 2)", "\\big)", "\\\\&+",
"3 \\cdot", "\\big(", "P(S > 2)", "-", "P(S > 3)", "\\big)", "\\\\&+",
"\\cdots",
tex_to_color_map=t2c
)
line2[1:12].align_to(line2[13], LEFT)
line3 = TexMobject(
"=",
"P(S > 0)", "+",
"P(S > 1)", "+",
"P(S > 2)", "+",
"P(S > 3)", "+",
"\\cdots",
tex_to_color_map=t2c,
)
line1.to_corner(UL)
line2.next_to(line1, DOWN, buff=MED_LARGE_BUFF)
line2.align_to(line1[1], LEFT)
line3.next_to(line2, DOWN, buff=MED_LARGE_BUFF)
line3.align_to(line1[1], LEFT)
# Write line 1
self.add(line1[:2])
self.play(Write(line1[2:7]))
self.wait()
self.play(FadeIn(line1[7]))
self.play(Write(line1[8:13]))
self.wait()
self.play(FadeIn(line1[13]))
self.play(Write(line1[14:19]))
self.wait()
self.play(Write(line1[19:]))
self.wait()
# line 2 scaffold
kw = {
"path_arc": 90 * DEGREES
}
bigs = line2.get_parts_by_tex("big")
self.play(
LaggedStart(
TransformFromCopy(
line1.get_part_by_tex("="),
line2.get_part_by_tex("="),
**kw
),
TransformFromCopy(
line1.get_parts_by_tex("\\cdot"),
line2.get_parts_by_tex("\\cdot"),
**kw
),
TransformFromCopy(
line1.get_parts_by_tex("+"),
line2.get_parts_by_tex("+"),
**kw
),
TransformFromCopy(
line1.get_part_by_tex("1"),
line2.get_part_by_tex("1"),
**kw
),
TransformFromCopy(
line1.get_part_by_tex("2"),
line2.get_part_by_tex("2"),
**kw
),
TransformFromCopy(
line1.get_part_by_tex("3"),
line2.get_part_by_tex("3"),
**kw
),
run_time=3,
lag_ratio=0,
),
LaggedStart(*[
GrowFromCenter(bigs[i:i + 2])
for i in range(0, len(bigs), 2)
])
)
self.wait()
# Expand out sum
for n in range(3):
i = 6 * n
j = 12 * n
rect1 = SurroundingRectangle(line1[i + 4:i + 7])
rect2 = SurroundingRectangle(line2[j + 4:j + 11])
color = line1[i + 5].get_color()
VGroup(rect1, rect2).set_stroke(color, 2)
self.play(ShowCreation(rect1))
self.play(
TransformFromCopy(
line1[i + 4:i + 7],
line2[j + 4:j + 7],
),
TransformFromCopy(
line1[i + 4:i + 7],
line2[j + 8:j + 11],
),
FadeIn(line2[j + 7]),
ReplacementTransform(rect1, rect2),
)
self.play(FadeOut(rect2))
# Show telescoping
line2.generate_target()
line2.target.set_opacity(0.2)
line2.target[4:7].set_opacity(1)
self.play(MoveToTarget(line2))
self.wait()
self.play(
TransformFromCopy(line2[0], line3[0]),
TransformFromCopy(line2[4:7], line3[1:4]),
)
self.wait()
line2.target.set_opacity(0.2)
VGroup(
line2.target[1:4],
line2.target[7:12],
line2.target[12:19],
line2.target[23],
).set_opacity(1)
self.play(MoveToTarget(line2))
self.wait()
self.play(
TransformFromCopy(line2[12], line3[4]),
TransformFromCopy(line2[16:19], line3[5:8]),
)
self.wait()
n = 12
line2.target.set_opacity(0.2)
VGroup(
line2.target[n + 1:n + 4],
line2.target[n + 7:n + 12],
line2.target[n + 12:n + 19],
line2.target[n + 23],
).set_opacity(1)
self.play(MoveToTarget(line2))
self.wait()
self.play(
TransformFromCopy(line2[n + 12], line3[8]),
TransformFromCopy(line2[n + 16:n + 19], line3[9:12]),
)
self.wait()
self.play(Write(line3[12:]))
self.wait()
rect = SurroundingRectangle(line3, buff=MED_SMALL_BUFF)
rect.set_stroke(WHITE, 2)
self.play(ShowCreation(rect))
self.wait()
self.wait(3)
class SubtractHistogramParts(ShowDistributionOfScores):
def construct(self):
n_scores = 10000
scores = np.array([self.get_random_score() for x in range(n_scores)])
axes = self.get_axes()
bars = self.get_histogram_bars(axes)
self.set_histogram_bars(bars, scores, axes)
self.add(axes)
self.add(bars)
# P(S = 2)
p2_arrow = Vector(
0.75 * DOWN,
max_stroke_width_to_length_ratio=10,
max_tip_length_to_length_ratio=0.35,
)
p2_arrow.next_to(bars[1], UP, SMALL_BUFF)
p2_arrow = VGroup(
p2_arrow.copy().set_stroke(BLACK, 9),
p2_arrow,
)
p2_label = TexMobject("P(S = 2)")
p2_label.next_to(p2_arrow, UP, SMALL_BUFF)
p2_label.set_color(bars[1].get_fill_color())
self.play(
GrowFromPoint(p2_arrow, p2_arrow.get_top()),
FadeInFromDown(p2_label),
bars[0].set_opacity, 0.1,
bars[2:].set_opacity, 0.1,
)
self.wait()
# Culumative probabilities
rhs = TexMobject("=", "P(S > 1)", "-", "P(S > 2)")
rhs[1].set_color(YELLOW)
rhs[3].set_color(bars[2].get_fill_color())
rhs[2:].set_opacity(0.2)
rhs.next_to(p2_label, RIGHT)
brace1 = Brace(bars[1:5], UP)[0]
brace1.next_to(rhs[1], DOWN)
brace1.match_color(rhs[1])
rf = 3.5
lf = 1.4
brace1[:2].stretch(rf, 0, about_edge=LEFT)
brace1[0].stretch(1 / rf, 0, about_edge=LEFT)
brace1[4:].stretch(lf, 0, about_edge=RIGHT)
brace1[5:].stretch(1 / lf, 0, about_edge=RIGHT)
brace2 = Brace(bars[2:], UP)
brace2.match_color(rhs[3])
brace2.set_width(10, about_edge=LEFT)
brace2.shift(1.5 * UP)
self.add(brace1, p2_arrow)
self.play(
FadeIn(rhs),
bars[2:].set_opacity, 1,
GrowFromPoint(brace1, rhs[1].get_bottom()),
p2_arrow.set_opacity, 0.5,
)
self.wait()
self.play(
rhs[:2].set_opacity, 0.2,
brace1.set_opacity, 0.2,
rhs[2:].set_opacity, 1,
bars[1].set_opacity, 0.1,
GrowFromCenter(brace2),
)
self.wait()
self.play(
bars[2:].set_opacity, 0.1,
bars[1].set_opacity, 1,
rhs.set_opacity, 1,
brace1.set_opacity, 1,
p2_arrow.set_opacity, 1,
)
self.wait()
# for i, part in enumerate(brace1):
# self.add(Integer(i).scale(0.5).move_to(part))
class GameWithSpecifiedScore(HyperdartScene):
CONFIG = {
"score": 1,
"random_seed": 1,
}
def construct(self):
board = VGroup(self.square, self.circle, self.circle_center_dot)
board.to_edge(DOWN, buff=0.5)
score_label = VGroup(
TextMobject("Score: "),
Integer(1)
)
score_label.scale(2)
score_label.arrange(RIGHT, aligned_edge=DOWN)
score_label.to_edge(UP, buff=0.25)
self.add(score_label)
score = 1
pace = "fast"
while True:
point = self.get_random_point()
want_to_continue = (score < self.score)
if want_to_continue:
while not self.is_inside(point):
point = self.get_random_point()
dart, dot = self.show_hit_with_dart(point)
score_label[1].increment_value()
lines = self.show_geometry(point, pace)
chord_and_shadow = self.show_circle_shrink(lines[1], pace=pace)
self.play(
FadeOut(VGroup(dart, dot, lines, chord_and_shadow)),
run_time=0.5,
)
score += 1
else:
while self.is_inside(point):
point = self.get_random_point()
self.show_miss(point)
self.play(ShowCreationThenFadeAround(score_label[1]))
self.wait()
return
class Score1Game(GameWithSpecifiedScore):
CONFIG = {
"score": 1,
}
class Score2Game(GameWithSpecifiedScore):
CONFIG = {
"score": 2,
}
class Score3Game(GameWithSpecifiedScore):
CONFIG = {
"score": 3,
}
class Score4Game(GameWithSpecifiedScore):
CONFIG = {
"score": 4,
}
class HistogramScene(ShowDistributionOfScores):
CONFIG = {
"n_scores": 10000,
"mean_line_height": 4,
}
def setup(self):
self.scores = np.array([
self.get_random_score()
for x in range(self.n_scores)
])
self.axes = self.get_axes()
self.bars = self.get_histogram_bars(self.axes)
self.set_histogram_bars(self.bars, self.scores, self.axes)
self.add(self.axes)
self.add(self.bars)
def get_mean_label(self):
mean_line = DashedLine(ORIGIN, self.mean_line_height * UP)
mean_line.set_stroke(YELLOW, 2)
mean = np.mean(self.scores)
mean_line.move_to(self.axes.c2p(mean, 0), DOWN)
mean_label = VGroup(
*TextMobject("E[S]", "="),
DecimalNumber(mean, num_decimal_places=3),
)
mean_label.arrange(RIGHT)
mean_label.match_color(mean_line)
mean_label.next_to(
mean_line.get_end(), UP, SMALL_BUFF,
index_of_submobject_to_align=0,
)
return VGroup(mean_line, *mean_label)
class ExpectedValueFromBars(HistogramScene):
def construct(self):
axes = self.axes
bars = self.bars
mean_label = self.get_mean_label()
mean_label.remove(mean_label[-1])
equation = TexMobject(
"P(S = 1)", "\\cdot", "1", "+",
"P(S = 2)", "\\cdot", "2", "+",
"P(S = 3)", "\\cdot", "3", "+",
"\\cdots"
)
equation.scale(0.9)
equation.next_to(mean_label[-1], RIGHT)
equation.shift(LEFT)
for i in range(3):
equation.set_color_by_tex(
str(i + 1), bars[i].get_fill_color()
)
equation[4:].set_opacity(0.2)
self.add(mean_label)
self.play(
mean_label[1:].shift, LEFT,
FadeInFrom(equation, LEFT)
)
p_parts = VGroup()
p_part_copies = VGroup()
for i in range(3):
bar = bars[i]
num = axes.x_axis.numbers[i]
p_part = equation[4 * i]
s_part = equation[4 * i + 2]
p_part_copy = p_part.copy()
p_part_copy.set_width(0.8 * bar.get_width())
p_part_copy.next_to(bar, UP, SMALL_BUFF)
p_part_copy.set_opacity(1)
self.remove(mean_label[0])
self.play(
bars[:i + 1].set_opacity, 1,
bars[i + 1:].set_opacity, 0.2,
equation[:4 * (i + 1)].set_opacity, 1,
FadeInFromDown(p_part_copy),
Animation(mean_label[0]),
)
kw = {
"surrounding_rectangle_config": {
"color": bar.get_fill_color(),
"buff": 0.5 * SMALL_BUFF,
}
}
self.play(
LaggedStart(
AnimationGroup(
ShowCreationThenFadeAround(p_part, **kw),
ShowCreationThenFadeAround(p_part_copy, **kw),
),
AnimationGroup(
ShowCreationThenFadeAround(s_part, **kw),
ShowCreationThenFadeAround(num, **kw),
),
lag_ratio=0.5,
)
)
self.wait()
p_parts.add(p_part)
p_part_copies.add(p_part_copy)
self.add(bars, mean_label)
self.play(
bars.set_opacity, 1,
equation.set_opacity, 1,
FadeOut(p_part_copies)
)
braces = VGroup(*[
Brace(p_part, UP)
for p_part in p_parts
])
for brace in braces:
brace.add(brace.get_text("???"))
self.play(LaggedStartMap(FadeIn, braces))
self.wait()
class ProbabilitySGtOne(HistogramScene):
def construct(self):
axes = self.axes
bars = self.bars
brace = Brace(bars[1:], UP)
label = brace.get_tex("P(S > 1)")
brace[0][:2].stretch(1.5, 0, about_edge=LEFT)
outlines = bars[1:].copy()
for bar in outlines:
bar.set_stroke(bar.get_fill_color(), 2)
bar.set_fill(opacity=0)
self.play(
GrowFromEdge(brace, LEFT),
bars[0].set_opacity, 0.2,
bars[1:].set_opacity, 0.8,
ShowCreationThenFadeOut(outlines),
FadeInFrom(label, LEFT),
)
self.wait()
square = Square()
square.set_fill(BLUE, 0.75)
square.set_stroke(WHITE, 1)
square.set_height(0.5)
circle = Circle()
circle.set_fill(RED, 0.75)
circle.set_stroke(WHITE, 1)
circle.set_height(0.5)
bar = Line(LEFT, RIGHT)
bar.set_stroke(WHITE, 3)
bar.set_width(0.5)
geo_frac = VGroup(circle, bar, square)
geo_frac.arrange(DOWN, SMALL_BUFF, buff=SMALL_BUFF)
rhs = VGroup(
TexMobject("="),
geo_frac,
TexMobject("= \\frac{\\pi}{4}")
)
rhs.arrange(RIGHT)
rhs.next_to(label)
shift_val = 2.05 * LEFT + 0.25 * UP
rhs.shift(shift_val)
self.play(
label.shift, shift_val,
FadeInFrom(rhs, LEFT)
)
self.wait()
# P(S > 2)
new_brace = brace.copy()
new_brace.next_to(
bars[2], UP,
buff=SMALL_BUFF,
aligned_edge=LEFT,
)
self.add(new_brace)
new_label = TexMobject(
"P(S > 2)", "=", "\\,???"
)
new_label.next_to(new_brace[0][2], UP)
self.play(
bars[1].set_opacity, 0.2,
label.set_opacity, 0.5,
rhs.set_opacity, 0.5,
brace.set_opacity, 0.5,
GrowFromEdge(new_brace, LEFT),
ReplacementTransform(
new_label.copy().fade(1).move_to(label, LEFT),
new_label,
)
)
self.wait()
new_rhs = TexMobject(
"{\\text{4d ball}", " \\over", " \\text{4d cube}}",
# "=",
# "{\\pi^2 / 2", "\\over", "2^4}"
)
new_rhs[0].set_color(RED)
new_rhs[2].set_color(BLUE)
new_rhs.move_to(new_label[-1], LEFT)
shift_val = 0.75 * LEFT + 0.15 * UP
new_rhs.shift(shift_val)
new_label.generate_target()
new_label.target.shift(shift_val)
new_label.target[-1].set_opacity(0)
self.play(
MoveToTarget(new_label),
FadeInFrom(new_rhs, LEFT)
)
self.wait()
# P(S > 3)
final_brace = brace.copy()
final_brace.set_opacity(1)
final_brace.next_to(
bars[3], UP,
buff=SMALL_BUFF,
aligned_edge=LEFT,
)
self.add(final_brace)
final_label = TexMobject("P(S > 3)")
final_label.next_to(final_brace[0][2], UP, SMALL_BUFF)
self.play(
bars[2].set_opacity, 0.2,
new_label[:-1].set_opacity, 0.5,
new_rhs.set_opacity, 0.5,
new_brace.set_opacity, 0.5,
GrowFromEdge(final_brace, LEFT),
ReplacementTransform(
final_label.copy().fade(1).move_to(new_label, LEFT),
final_label,
),
axes.x_axis[-1].set_opacity, 0,
)
self.wait()
class VolumsOfNBalls(Scene):
def construct(self):
title, alt_title = [
TextMobject(
"Volumes of " + tex + "-dimensional balls",
tex_to_color_map={tex: YELLOW},
)
for tex in ["$N$", "$2n$"]
]
for mob in [title, alt_title]:
mob.scale(1.5)
mob.to_edge(UP)
formulas = VGroup(*[
TexMobject(
tex,
tex_to_color_map={"R": WHITE}
)
for tex in [
"2R",
"\\pi R^2",
"\\frac{4}{3} \\pi R^3",
"\\frac{1}{2} \\pi^2 R^4",
"\\frac{8}{15} \\pi^2 R^5",
"\\frac{1}{6} \\pi^3 R^6",
"\\frac{16}{105} \\pi^3 R^7",
"\\frac{1}{24} \\pi^4 R^8",
"\\frac{32}{945} \\pi^4 R^9",
"\\frac{1}{120} \\pi^5 R^{10}",
"\\frac{64}{10{,}395} \\pi^5 R^{11}",
"\\frac{1}{720} \\pi^6 R^{12}",
]
])
formulas.arrange(RIGHT, buff=LARGE_BUFF)
formulas.scale(0.9)
formulas.to_edge(LEFT)
lines = VGroup()
d_labels = VGroup()
for dim, formula in zip(it.count(1), formulas):
label = VGroup(Integer(dim), TexMobject("D"))
label.arrange(RIGHT, buff=0, aligned_edge=DOWN)
label[0].set_color(YELLOW)
label.move_to(formula)
label.shift(UP)
line = Line(UP, DOWN)
line.set_stroke(WHITE, 1)
line.next_to(formula, RIGHT, buff=MED_LARGE_BUFF)
line.shift(0.5 * UP)
d_labels.add(label)
lines.add(line)
# coefs.add(formula[0])
formula[0].set_color(BLUE_B)
lines.remove(lines[-1])
line = Line(formulas.get_left(), formulas.get_right())
line.set_stroke(WHITE, 1)
line.next_to(d_labels, DOWN, MED_SMALL_BUFF)
lines.add(line)
chart = VGroup(lines, d_labels, formulas)
chart.save_state()
self.add(title)
self.add(d_labels)
self.add(lines)
self.play(LaggedStartMap(FadeInFromDown, formulas, run_time=3, lag_ratio=0.1))
self.play(chart.to_edge, RIGHT, {"buff": MED_SMALL_BUFF}, run_time=5)
self.wait()
self.play(Restore(chart))
self.play(FadeOut(formulas[4:]))
rect1 = SurroundingRectangle(formulas[2][0][-1])
rect2 = SurroundingRectangle(formulas[3][0][-2:])
self.play(ShowCreation(rect1))
self.play(TransformFromCopy(rect1, rect2))
self.play(FadeOut(VGroup(rect1, rect2)))
arrows = VGroup(*[
Arrow(
formulas[i].get_bottom(),
formulas[i + 1].get_bottom(),
path_arc=150 * DEGREES,
)
for i in (1, 2)
])
for arrow in arrows:
self.play(ShowCreation(arrow))
self.wait()
self.play(
FadeOut(arrows),
FadeIn(formulas[4:]),
)
# General formula for even dimensions
braces = VGroup(*[
Brace(formula, DOWN)
for formula in formulas[1::2]
])
gen_form = TexMobject("{\\pi^n \\over n!}", "R^{2n}")
gen_form[0].set_color(BLUE_B)
gen_form.scale(1.5)
gen_form.to_edge(DOWN)
self.play(
formulas[::2].set_opacity, 0.25,
ReplacementTransform(title, alt_title)
)
for brace in braces[:3]:
self.play(GrowFromCenter(brace))
self.wait()
self.play(
FadeOut(braces[:3]),
FadeInFrom(gen_form, UP),
)
self.wait()
class RepeatedSamplesGame(Scene):
def construct(self):
pass
# Old scenes, before decision to collaborate with numberphile
class IntroduceGame(HyperdartScene):
CONFIG = {
"random_seed": 0,
"square_width": 5,
"num_darts_in_initial_flurry": 5,
}
def construct(self):
self.show_flurry_of_points()
self.show_board_dimensions()
self.introduce_bullseye()
self.show_miss_example()
self.show_shrink_rule()
def show_flurry_of_points(self):
square = self.square
circle = self.circle
title = TextMobject("Hyperdarts")
title.scale(1.5)
title.to_edge(UP)
n = self.num_darts_in_initial_flurry
points = np.random.normal(size=n * 3).reshape((n, 3))
points[:, 2] = 0
points *= 0.75
board = Dartboard()
board.match_width(square)
board.move_to(square)
pre_square = Circle(color=WHITE)
pre_square.replace(square)
self.remove(circle, square)
self.add(board)
darts, dots = self.show_hits_with_darts(
points,
added_anims=[FadeInFromDown(title)]
)
self.wait()
def func(p):
theta = angle_of_vector(p) % (TAU / 4)
if theta > TAU / 8:
theta = TAU / 4 - theta
p *= 1 / np.cos(theta)
return p
self.play(
*[
ApplyPointwiseFunction(func, pieces, run_time=1)
for pieces in [*board[:3], *dots]
],
*[
MaintainPositionRelativeTo(dart, dot)
for dart, dot in zip(darts, dots)
]
)
self.flurry_dots = dots
self.darts = darts
self.title = title
self.board = board
def show_board_dimensions(self):
square = self.square
labels = VGroup(*[
TextMobject("2 ft").next_to(
square.get_edge_center(vect), vect,
)
for vect in [DOWN, RIGHT]
])
labels.set_color(YELLOW)
h_line, v_line = lines = VGroup(*[
DashedLine(
square.get_edge_center(v1),
square.get_edge_center(-v1),
).next_to(label, v2)
for label, v1, v2 in zip(labels, [LEFT, UP], [UP, LEFT])
])
lines.match_color(labels)
self.play(
LaggedStartMap(ShowCreation, lines),
LaggedStartMap(FadeInFromDown, labels),
lag_ratio=0.5
)
self.wait()
self.square_dimensions = VGroup(lines, labels)
def introduce_bullseye(self):
square = self.square
circle = self.circle
board = self.board
circle.save_state()
circle.replace(board[-1])
label = TextMobject("Bullseye")
label.scale(1.5)
label.next_to(square, LEFT, aligned_edge=UP)
label.set_color(RED)
arrow = Arrow(
label.get_bottom(),
circle.get_corner(DR)
)
radius = DashedLine(
square.get_center(),
square.get_left(),
stroke_width=2,
)
radius_label = TextMobject("1 ft")
radius_label.next_to(radius, DOWN, SMALL_BUFF)
self.add(circle, self.square_dimensions)
self.play(
FadeInFromLarge(circle),
FadeInFromDown(label),
ShowCreation(arrow),
LaggedStartMap(FadeOut, self.flurry_dots, run_time=1),
LaggedStartMap(FadeOut, self.darts, run_time=1),
)
self.wait()
self.add(square, board, arrow, circle)
self.play(
Restore(circle),
ApplyMethod(
arrow.scale, 0.4,
{"about_point": arrow.get_start()}
),
)
self.add(radius, self.circle_center_dot)
self.play(
ShowCreation(radius),
FadeInFrom(radius_label, RIGHT),
FadeIn(self.circle_center_dot),
)
self.play(
FadeOut(label),
Uncreate(arrow),
FadeOut(board)
)
self.wait()
s_lines, s_labels = self.square_dimensions
self.play(
FadeOut(s_lines),
FadeOut(radius),
FadeOut(radius_label),
FadeOut(self.title),
)
self.circle_dimensions = VGroup(
radius, radius_label,
)
def show_miss_example(self):
square = self.square
point = square.get_corner(UL) + 0.5 * DR
miss_word = TextMobject("Miss!")
miss_word.scale(1.5)
miss_word.next_to(point, UP, LARGE_BUFF)
dart, dot = self.show_hit_with_dart(point)
self.play(FadeInFromDown(miss_word))
self.wait()
game_over = self.show_game_over()
self.wait()
self.play(
*map(FadeOut, [dart, dot, miss_word, game_over])
)
def show_shrink_rule(self):
circle = self.circle
point = 0.5 * circle.point_from_proportion(0.2)
# First example
self.show_full_hit_process(point)
self.wait()
# Close to border
label = TextMobject("Bad shot $\\Rightarrow$ much shrinkage")
label.scale(1.5)
label.to_edge(UP)
point = 0.98 * circle.point_from_proportion(3 / 8)
circle.save_state()
self.play(FadeInFromDown(label))
self.show_full_hit_process(point)
self.wait()
self.play(Restore(circle))
# Close to center
new_label = TextMobject("Good shot $\\Rightarrow$ less shrinkage")
new_label.scale(1.5)
new_label.to_edge(UP)
point = 0.2 * circle.point_from_proportion(3 / 8)
self.play(
FadeInFromDown(new_label),
FadeOutAndShift(label, UP),
)
self.show_full_hit_process(point)
self.wait()
self.play(FadeOut(new_label))
# Play on
for x in range(3):
r1, r2 = np.random.random(size=2)
point = r1 * circle.point_from_proportion(r2)
self.show_full_hit_process(point)
point = circle.get_right() + 0.5 * UR
self.show_miss(point)
self.wait()
self.show_game_over()
class ShowScoring(HyperdartScene):
def setup(self):
super().setup()
self.add_score_counter()
def construct(self):
self.comment_on_score()
self.show_several_hits()
def comment_on_score(self):
score_label = self.score_label
comment = TextMobject("\\# Bullseyes")
# rect = SurroundingRectangle(comment)
# rect.set_stroke(width=1)
# comment.add(rect)
comment.set_color(YELLOW)
comment.next_to(score_label, DOWN, LARGE_BUFF)
comment.set_x(midpoint(
self.square.get_left(),
LEFT_SIDE,
)[0])
arrow = Arrow(
comment.get_top(),
score_label[1].get_bottom(),
buff=0.2,
)
arrow.match_color(comment)
self.play(
FadeInFromDown(comment),
GrowArrow(arrow),
)
def show_several_hits(self):
points = [UR, DL, 0.5 * UL, 0.5 * DR]
for point in points:
self.show_full_hit_process(point, pace="fast")
self.show_miss(2 * UR)
self.wait()
#
def add_score_counter(self):
score = Integer(0)
score_label = VGroup(
TextMobject("Score: "),
score
)
score_label.arrange(RIGHT, aligned_edge=DOWN)
score_label.scale(1.5)
score_label.to_corner(UL)
self.add(score_label)
self.score = score
self.score_label = score_label
def increment_score(self):
score = self.score
new_score = score.copy()
new_score.increment_value(1)
self.play(
FadeOutAndShift(score, UP),
FadeInFrom(new_score, DOWN),
run_time=1,
)
self.remove(new_score)
score.increment_value()
score.move_to(new_score)
self.add(score)
def show_hit(self, point, *args, **kwargs):
result = super().show_hit(point, *args, **kwargs)
if self.is_inside(point):
self.increment_score()
return result
def show_hit_with_dart(self, point, *args, **kwargs):
result = super().show_hit_with_dart(point, *args, **kwargs)
if self.is_inside(point):
self.increment_score()
return result
class ShowSeveralRounds(ShowScoring):
CONFIG = {
"n_rounds": 5,
}
def construct(self):
for x in range(self.n_rounds):
self.show_single_round()
self.reset_board()
def show_single_round(self, pace="fast"):
while True:
point = self.get_random_point()
if self.is_inside(point):
self.show_full_hit_process(point, pace=pace)
else:
to_fade = self.show_miss(point)
self.wait(0.5)
self.play(
ShowCreationThenFadeAround(self.score_label),
FadeOut(to_fade)
)
return
def reset_board(self):
score = self.score
new_score = score.copy()
new_score.set_value(0)
self.play(
self.circle.match_width, self.square,
FadeOutAndShift(score, UP),
FadeInFrom(new_score, DOWN),
)
score.set_value(0)
self.add(score)
self.remove(new_score)
class ShowSeveralRoundsQuickly(ShowSeveralRounds):
CONFIG = {
"n_rounds": 15,
}
def show_full_hit_process(self, point, *args, **kwargs):
lines = self.get_all_hit_lines(point)
dart = self.show_hit_with_dart(point)
self.add(lines)
self.score.increment_value(1)
to_fade = self.show_circle_shrink(lines[1], pace="fast")
to_fade.add(*lines, *dart)
self.play(FadeOut(to_fade), run_time=0.5)
def increment_score(self):
pass # Handled elsewhere
class ShowSeveralRoundsVeryQuickly(ShowSeveralRoundsQuickly):
def construct(self):
pass
class ShowUniformDistribution(HyperdartScene):
CONFIG = {
"dart_sound": "dart_high",
"n_points": 1000,
}
def construct(self):
self.add_title()
self.show_random_points()
self.exchange_titles()
self.show_random_points()
def get_square(self):
return super().get_square().to_edge(DOWN)
def add_title(self):
# square = self.square
title = TextMobject("All points in the square are equally likely")
title.scale(1.5)
title.to_edge(UP)
new_title = TextMobject("``Uniform distribution'' on the square")
new_title.scale(1.5)
new_title.to_edge(UP)
self.play(FadeInFromDown(title))
self.title = title
self.new_title = new_title
def show_random_points(self):
points = self.get_random_points(self.n_points)
dots = VGroup(*[
Dot(point, radius=0.02)
for point in points
])
dots.set_fill(opacity=0.75)
run_time = 5
self.play(LaggedStartMap(
FadeInFromLarge, dots,
run_time=run_time,
))
for x in range(1000):
self.add_dart_sound(
time_offset=-run_time * np.random.random(),
gain=-10,
gain_to_background=-5,
)
self.wait()
def exchange_titles(self):
self.play(
FadeInFromDown(self.new_title),
FadeOutAndShift(self.title, UP),
)
class ExpectedScoreEqualsQMark(Scene):
def construct(self):
equation = TextMobject(
"\\textbf{E}[Score] = ???",
tex_to_color_map={
"???": YELLOW,
}
)
aka = TextMobject("a.k.a. Long-term average")
aka.next_to(equation, DOWN)
self.play(Write(equation))
self.wait(2)
self.play(FadeInFrom(aka, UP))
self.wait()