Finally, some work on the beta video

This commit is contained in:
Grant Sanderson
2020-02-18 22:43:23 -08:00
parent 671042cd20
commit 07cda695bb
2 changed files with 346 additions and 2 deletions

View File

@ -1,9 +1,10 @@
from manimlib.imports import *
from from_3b1b.active.bayes.beta_helpers import *
OUTPUT_DIRECTORY = "bayes/beta"
class BarChart(Axes):
class Histogram(Axes):
CONFIG = {
"x_min": 0,
"x_max": 10,
@ -72,7 +73,6 @@ class BarChart(Axes):
pass
# Bar manipulations
# Scenes
@ -81,3 +81,239 @@ class BarChartTest(Scene):
bar_chart = BarChart()
bar_chart.to_edge(DOWN)
self.add(bar_chart)
class Thumbnail(Scene):
def construct(self):
t2c = {
"95\\%": BLUE,
"92\\%": YELLOW,
"50": BLUE_C,
"200": YELLOW,
}
kw = {"tex_to_color_map": t2c}
text = VGroup(
TextMobject("95\\% with 50 reviews", **kw),
TextMobject("vs.", **kw),
TextMobject("92\\% with 200 reviews", **kw),
)
text.scale(2)
text.arrange(DOWN, buff=LARGE_BUFF)
text.set_width(FRAME_WIDTH - 1)
self.add(text)
self.embed()
class AskAboutUnknownProbabilities(Scene):
def construct(self):
# Setup
unknown_title, prob_title = titles = self.get_titles()
v_line = Line(UP, DOWN)
v_line.set_height(FRAME_HEIGHT)
v_line.set_stroke([WHITE, LIGHT_GREY], 3)
h_line = Line(LEFT, RIGHT)
h_line.set_width(FRAME_WIDTH)
h_line.next_to(titles, DOWN)
processes = VGroup(
get_random_coin(shuffle_time=1),
get_random_die(shuffle_time=1.20),
get_random_card(shuffle_time=2),
)
processes.arrange(DOWN, buff=0.7)
processes.next_to(unknown_title, DOWN, LARGE_BUFF)
processes_rect = BackgroundRectangle(processes)
processes_rect.set_fill(BLACK, 1)
prob_labels = VGroup(
TexMobject("P(", "00", ")", "=", "1 / 2"),
TexMobject("P(", "00", ")", "=", "1 / 6}"),
TexMobject("P(", "00", ")", "=", "1 / 52}"),
)
prob_labels.scale(1.5)
prob_labels.arrange(DOWN, aligned_edge=LEFT)
prob_labels.match_x(prob_title)
for pl, pr in zip(prob_labels, processes):
pl.match_y(pr)
content = pr[1].copy()
content.replace(pl[1], dim_to_match=0)
pl.submobjects[1] = content
# Putting numbers to the unknown
number_rects = VGroup(*[
SurroundingRectangle(pl[-1])
for pl in prob_labels
])
number_rects.set_stroke(YELLOW, 2)
for pl in prob_labels:
pl.save_state()
pl[:3].match_x(prob_title)
pl[3:].match_x(prob_title)
pl.set_opacity(0)
self.add(processes)
self.play(
LaggedStartMap(FadeInFromDown, titles),
LaggedStart(
ShowCreation(v_line),
ShowCreation(h_line),
),
run_time=1
)
self.wait(2)
self.play(
LaggedStartMap(Restore, prob_labels),
run_time=3,
lag_ratio=0.3,
)
self.play(
LaggedStartMap(
ShowCreationThenFadeOut,
number_rects,
run_time=3,
)
)
self.wait(2)
# Highlight coin flip
fade_rect = BackgroundRectangle(
VGroup(prob_labels[1:], processes[1:]),
buff=MED_SMALL_BUFF,
)
fade_rect.set_width(FRAME_WIDTH, stretch=True)
fade_rect.set_fill(BLACK, 0.8)
prob_half = prob_labels[0]
half = prob_half[-1]
half_underline = Line(LEFT, RIGHT)
half_underline.set_width(half.get_width() + MED_SMALL_BUFF)
half_underline.next_to(half, DOWN, buff=SMALL_BUFF)
half_underline.set_stroke(YELLOW, 3)
self.add(fade_rect, v_line, prob_half)
self.play(FadeIn(fade_rect))
self.wait(2)
self.play(
ShowCreation(half_underline),
half.set_color, YELLOW,
)
self.play(FadeOut(half_underline))
self.wait(4)
# Transition to question
processes.suspend_updating()
self.play(
LaggedStart(
FadeOutAndShift(unknown_title, UP),
FadeOutAndShift(prob_title, UP),
lag_ratio=0.2,
),
FadeOutAndShift(h_line, UP, lag_ratio=0.1),
FadeOutAndShift(processes, LEFT, lag_ratio=0.1),
FadeOut(prob_labels[1]),
FadeOut(prob_labels[2]),
ApplyMethod(fade_rect.set_fill, BLACK, 1, remover=True),
v_line.rotate, 90 * DEGREES,
v_line.shift, 0.6 * FRAME_HEIGHT * UP,
prob_half.center,
prob_half.to_edge, UP,
run_time=2,
)
self.clear()
self.add(prob_half)
arrow = Vector(UP)
arrow.next_to(half, DOWN)
question = TextMobject("What exactly does\\\\this mean?")
question.next_to(arrow, DOWN)
self.play(
GrowArrow(arrow),
FadeInFrom(question, UP),
)
self.wait(2)
self.play(
FadeOutAndShift(question, RIGHT),
Rotate(arrow, 90 * DEGREES),
VFadeOut(arrow),
)
# Show long run averages
self.show_many_coins(20, 50)
self.show_many_coins(40, 100)
# Make probability itself unknown
q_marks = TexMobject("???")
q_marks.set_color(YELLOW)
q_marks.replace(half, dim_to_match=0)
randy = Randolph(mode="confused")
randy.center()
randy.look_at(prob_half)
self.play(
FadeOutAndShift(half, UP),
FadeInFrom(q_marks, DOWN),
)
self.play(FadeIn(randy))
self.play(Blink(randy))
self.wait()
# self.embed()
def get_titles(self):
unknown_label = TextMobject("Unknown event")
prob_label = TextMobject("Probability")
titles = VGroup(unknown_label, prob_label)
titles.scale(1.5)
unknown_label.move_to(FRAME_WIDTH * LEFT / 4)
prob_label.move_to(FRAME_WIDTH * RIGHT / 4)
titles.to_edge(UP, buff=MED_SMALL_BUFF)
titles.set_color(BLUE)
return titles
def show_many_coins(self, n_rows, n_cols):
coin_choices = VGroup(
get_coin(BLUE_E, "H"),
get_coin(RED_E, "T"),
)
coin_choices.set_stroke(width=0)
coins = VGroup(*[
random.choice(coin_choices).copy()
for x in range(n_rows * n_cols)
])
def organize_coins(coin_group):
coin_group.scale(1 / coin_group[0].get_height())
coin_group.arrange_in_grid(n_rows=n_rows)
coin_group.set_width(FRAME_WIDTH - 1)
coin_group.to_edge(DOWN, MED_LARGE_BUFF)
organize_coins(coins)
sorted_coins = VGroup()
for coin in coins:
coin.generate_target()
sorted_coins.add(coin.target)
sorted_coins.submobjects.sort(key=lambda m: m.symbol)
organize_coins(sorted_coins)
self.play(LaggedStartMap(
FadeInFrom, coins,
lambda m: (m, 0.2 * DOWN),
run_time=3,
rate_func=linear
))
self.wait()
self.play(LaggedStartMap(
MoveToTarget, coins,
path_arc=30 * DEGREES,
run_time=2,
lag_ratio=1 / len(coins),
))
self.wait()
self.play(FadeOut(coins))

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@ -0,0 +1,108 @@
from manimlib.imports import *
# Images of randomness
def get_random_process(choices, shuffle_time=2, total_time=4, change_rate=0.05,
h_buff=0.05, v_buff=0.05):
content = choices[0]
container = Square()
container.set_opacity(0)
container.set_width(content.get_width() + 2 * h_buff, stretch=True)
container.set_height(content.get_height() + 2 * v_buff, stretch=True)
container.move_to(content)
container.add(content)
container.time = 0
container.last_change_time = 0
def update(container, dt):
container.time += dt
time = container.time
change = all([
(time % total_time) < shuffle_time,
(time - container.last_change_time) > change_rate,
])
if change:
mob = container.submobjects[0]
new_mob = random.choice(choices)
new_mob.match_height(mob)
new_mob.move_to(container, DL)
new_mob.shift(2 * np.random.random() * h_buff * RIGHT)
new_mob.shift(2 * np.random.random() * v_buff * UP)
container.submobjects = [new_mob]
container.last_change_time = time
container.add_updater(update)
return container
def get_coin(color, symbol):
coin = VGroup()
circ = Circle()
circ.set_fill(color, 1)
circ.set_stroke(WHITE, 2)
circ.set_height(1)
label = TextMobject(symbol)
label.set_height(0.5 * circ.get_height())
label.move_to(circ)
coin.add(circ, label)
coin.symbol = symbol
coin.lock_triangulation()
return coin
def get_random_coin(**kwargs):
coins = VGroup(
get_coin(BLUE_E, "H"),
get_coin(RED_E, "T"),
)
return get_random_process(coins, **kwargs)
def get_die_faces():
dot = Dot()
dot.set_width(0.15)
dot.set_color(BLUE_B)
square = Square()
square.round_corners(0.25)
square.set_stroke(WHITE, 2)
square.set_fill(DARKER_GREY, 1)
square.set_width(0.6)
edge_groups = [
(ORIGIN,),
(UL, DR),
(UL, ORIGIN, DR),
(UL, UR, DL, DR),
(UL, UR, ORIGIN, DL, DR),
(UL, UR, LEFT, RIGHT, DL, DR),
]
arrangements = VGroup(*[
VGroup(*[
dot.copy().move_to(square.get_bounding_box_point(ec))
for ec in edge_group
])
for edge_group in edge_groups
])
square.set_width(1)
faces = VGroup(*[
VGroup(square.copy(), arrangement)
for arrangement in arrangements
])
faces.arrange(RIGHT)
return faces
def get_random_die(**kwargs):
return get_random_process(get_die_faces(), **kwargs)
def get_random_card(height=1, **kwargs):
cards = DeckOfCards()
cards.set_height(height)
return get_random_process(cards, **kwargs)