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https://github.com/3b1b/manim.git
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Halfway through CreateFormulaFromDiagram
This commit is contained in:
Grant Sanderson
@ -70,6 +70,7 @@ class BayesDiagram(VGroup):
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"evidence_color2": EVIDENCE_COLOR2,
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"not_evidence_color1": NOT_EVIDENCE_COLOR1,
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"not_evidence_color2": NOT_EVIDENCE_COLOR2,
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"prior_rect_direction": DOWN,
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}
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def __init__(self, prior, likelihood, antilikelihood, **kwargs):
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@ -120,24 +121,93 @@ class BayesDiagram(VGroup):
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self.square.set_opacity(0)
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self.hypothesis_split.set_opacity(0)
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def generate_braces(self, buff=SMALL_BUFF):
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kw = {"buff": buff}
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self.h_brace = Brace(self.h_rect, DOWN, **kw)
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self.nh_brace = Brace(self.nh_rect, DOWN, **kw)
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self.he_brace = Brace(self.he_rect, LEFT, **kw)
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self.hne_brace = Brace(self.hne_rect, LEFT, **kw)
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self.nhe_brace = Brace(self.nhe_rect, RIGHT, **kw)
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self.nhne_brace = Brace(self.nhne_rect, RIGHT, **kw)
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def add_brace_attrs(self, buff=SMALL_BUFF):
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braces = self.braces = self.create_braces(buff)
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self.braces_buff = buff
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attrs = [
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"h_brace",
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"nh_brace",
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"he_brace",
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"hne_brace",
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"nhe_brace",
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"nhne_brace",
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]
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for brace, attr in zip(braces, attrs):
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setattr(self, attr, brace)
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return self
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self.braces = VGroup(
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self.h_brace,
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self.nh_brace,
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self.he_brace,
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self.hne_brace,
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self.nhe_brace,
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self.nhne_brace,
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def create_braces(self, buff=SMALL_BUFF):
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kw = {"buff": buff}
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return VGroup(
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Brace(self.h_rect, self.prior_rect_direction, **kw),
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Brace(self.nh_rect, self.prior_rect_direction, **kw),
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Brace(self.he_rect, LEFT, **kw),
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Brace(self.hne_rect, LEFT, **kw),
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Brace(self.nhe_rect, RIGHT, **kw),
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Brace(self.nhne_rect, RIGHT, **kw),
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)
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def refresh_braces(self):
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if hasattr(self, "braces"):
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self.braces.become(
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self.create_braces(self.braces_buff)
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)
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return self
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def set_prior(self, new_prior):
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p = new_prior
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q = 1 - p
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full_width = self.square.get_width()
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left_rects = [self.h_rect, self.he_rect, self.hne_rect]
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right_rects = [self.nh_rect, self.nhe_rect, self.nhne_rect]
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for group, vect, value in [(left_rects, LEFT, p), (right_rects, RIGHT, q)]:
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for rect in group:
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rect.set_width(
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value * full_width,
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stretch=True,
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about_edge=vect,
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)
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self.refresh_braces()
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return self
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def general_set_likelihood(self, new_likelihood, low_rect, high_rect):
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height = self.square.get_height()
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low_rect.set_height(
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new_likelihood * height,
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stretch=True,
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about_edge=DOWN,
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)
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high_rect.set_height(
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(1 - new_likelihood) * height,
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stretch=True,
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about_edge=UP,
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)
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self.refresh_braces()
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return self
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def set_likelihood(self, new_likelihood):
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self.general_set_likelihood(
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new_likelihood,
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self.he_rect,
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self.hne_rect,
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)
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return self
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def set_antilikelihood(self, new_antilikelihood):
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self.general_set_likelihood(
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new_antilikelihood,
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self.nhe_rect,
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self.nhne_rect,
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)
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return self
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def copy(self):
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return self.deepcopy()
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class ProbabilityBar(VGroup):
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CONFIG = {
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@ -1722,7 +1792,7 @@ class HeartOfBayesTheorem(Scene):
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diagram.set_height(3)
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diagram.move_to(5 * LEFT + DOWN)
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diagram.generate_braces()
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diagram.add_brace_attrs()
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braces = VGroup(diagram.h_brace, diagram.nh_brace)
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diagram.add(*braces)
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icons = VGroup(LibrarianIcon(), FarmerIcon())
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@ -1812,10 +1882,12 @@ class WhenDoesBayesApply(DescriptionOfSteve):
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# Show icons
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self.play(FadeInFromDown(all_words[0]))
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self.play(
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FadeInFrom(hypothesis_icon[0], DOWN),
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Write(hypothesis_icon[1]),
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FadeInFrom(hypothesis_icon[2], UP),
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run_time=1,
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LaggedStart(
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FadeInFrom(hypothesis_icon[0], DOWN),
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Write(hypothesis_icon[1]),
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FadeInFrom(hypothesis_icon[2], UP),
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run_time=1,
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)
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)
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self.wait()
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@ -1859,6 +1931,13 @@ class WhenDoesBayesApply(DescriptionOfSteve):
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self.play(FadeOut(rects))
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self.wait()
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self.remove(prob)
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everything = Group(*self.get_mobjects())
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self.play(
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LaggedStartMap(FadeOut, everything, run_time=2),
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prob.copy().to_corner, UR,
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)
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def get_hypothesis_icon(self):
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group = VGroup(
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Steve().set_height(1.5),
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@ -1877,3 +1956,238 @@ class WhenDoesBayesApply(DescriptionOfSteve):
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rect.set_stroke(WHITE, 2)
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result.add(rect)
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return result
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class CreateFormulaFromDiagram(Scene):
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def construct(self):
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t2c = {
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"P": WHITE,
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"H": HYPOTHESIS_COLOR,
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"E": EVIDENCE_COLOR1,
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"\\neg": RED,
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}
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# Add posterior
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posterior = TexMobject("P(H|E)", tex_to_color_map=t2c)
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posterior.to_corner(UR)
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posterior_words = TextMobject("Goal: ")
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posterior_words.next_to(posterior, LEFT, aligned_edge=UP)
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self.add(posterior)
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self.add(posterior_words)
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# Show prior
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diagram = self.get_diagram()
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prior_label = TexMobject("P(H)", tex_to_color_map=t2c)
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prior_label.add_updater(
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lambda m: m.next_to(diagram.h_brace, UP, SMALL_BUFF)
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)
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prior_example = TexMobject("= 1 / 21")
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prior_example.add_updater(
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lambda m: m.next_to(prior_label, RIGHT).shift(0.03 * UP)
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)
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# example_words = TextMobject("In our example")
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# example_words.next_to(prior_example[0][1:], UP, buff=SMALL_BUFF, aligned_edge=LEFT)
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# prior_example.add(example_words)
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prior_arrow = Vector(0.7 * RIGHT)
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prior_arrow.next_to(prior_label, LEFT, SMALL_BUFF)
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prior_word = TextMobject("``Prior''")
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prior_word.next_to(prior_arrow, LEFT, SMALL_BUFF)
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prior_word.align_to(prior_label[0], DOWN)
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prior_word.set_color(HYPOTHESIS_COLOR)
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self.add(diagram)
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self.play(ShowIncreasingSubsets(diagram.people, run_time=2))
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self.wait()
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self.play(
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diagram.hypothesis_split.set_opacity, 1,
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FadeIn(diagram.h_brace),
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FadeInFromDown(prior_label),
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)
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self.wait()
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self.play(FadeIn(prior_example))
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self.play(
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LaggedStartMap(
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Indicate, diagram.people[::10],
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color=BLUE,
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)
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)
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self.wait()
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self.play(
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FadeInFrom(prior_word, RIGHT),
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GrowArrow(prior_arrow)
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)
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self.wait()
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# First likelihood split
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like_label = TexMobject("P(E|H)", tex_to_color_map=t2c)
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like_label.add_updater(
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lambda m: m.next_to(diagram.he_brace, LEFT)
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)
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like_example = TexMobject("= 0.4")
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like_example.add_updater(
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lambda m: m.next_to(like_label, DOWN)
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)
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like_word = TextMobject("``Likelihood''")
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like_word.next_to(like_label, UP, LARGE_BUFF, aligned_edge=RIGHT)
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like_arrow = Arrow(
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like_word.get_bottom(),
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like_label.get_top(),
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buff=0.2,
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)
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limit_arrow = Vector(0.5 * UP)
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limit_arrow.next_to(like_label.get_part_by_tex("|"), UP, SMALL_BUFF)
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limit_arrow.set_stroke(WHITE, 4)
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limit_word = TextMobject("Limit\\\\your\\\\view")
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limit_word.next_to(limit_arrow, UP)
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self.play(
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diagram.he_rect.set_opacity, 1,
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diagram.hne_rect.set_opacity, 1,
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GrowFromCenter(diagram.he_brace),
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FadeInFrom(like_label, RIGHT),
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FadeInFrom(like_example, RIGHT),
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)
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self.wait()
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self.play(
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ShowCreationThenFadeAround(
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like_label.get_part_by_tex("E"),
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surrounding_rectangle_config={
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"color": EVIDENCE_COLOR1
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}
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),
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)
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self.play(WiggleOutThenIn(like_label.get_part_by_tex("|")))
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self.play(
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ShowCreationThenFadeAround(
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like_label.get_part_by_tex("H")
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),
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)
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self.wait()
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self.play(
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diagram.people[10:].set_opacity, 0.2,
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diagram.nh_rect.set_opacity, 0.2,
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FadeInFrom(limit_word, DOWN),
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GrowArrow(limit_arrow),
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rate_func=there_and_back_with_pause,
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run_time=6,
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)
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self.wait()
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self.play(
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Write(like_word, run_time=1),
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GrowArrow(like_arrow),
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)
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self.wait()
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# Show anti-likelihood
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anti_label = TexMobject("P(E| \\neg H)", tex_to_color_map=t2c)
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anti_label.add_updater(
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lambda m: m.next_to(diagram.nhe_brace, RIGHT)
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)
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anti_example = TexMobject("= 0.1")
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anti_example.add_updater(
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lambda m: m.next_to(anti_label, RIGHT).align_to(anti_label[0], DOWN)
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)
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neg_sym = anti_label.get_part_by_tex("\\neg").copy()
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neg_sym.generate_target()
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neg_sym.target.scale(2.5)
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not_word = TextMobject("means ``not''")
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neg_group = VGroup(neg_sym.target, not_word)
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neg_group.arrange(RIGHT)
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neg_group.next_to(anti_label, UP, LARGE_BUFF)
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neg_group.to_edge(RIGHT, buff=MED_SMALL_BUFF)
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diagram.nhe_rect.set_opacity(1)
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diagram.nhe_rect.save_state()
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diagram.nhe_rect.become(diagram.nh_rect)
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self.play(
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Restore(diagram.nhe_rect),
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GrowFromCenter(diagram.nhe_brace),
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FadeInFrom(anti_label, LEFT),
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FadeInFrom(anti_example, LEFT),
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)
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diagram.nhne_rect.set_opacity(1)
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self.wait()
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self.play(
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ShowCreationThenFadeAround(
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anti_label[2],
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surrounding_rectangle_config={"color": EVIDENCE_COLOR1},
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)
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)
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self.play(
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ShowCreationThenFadeAround(
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anti_label[4:6],
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surrounding_rectangle_config={"color": RED},
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)
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)
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self.wait()
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self.play(
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MoveToTarget(neg_sym),
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FadeIn(not_word)
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)
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self.wait()
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self.play(
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FadeOut(not_word),
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Transform(neg_sym, anti_label.get_part_by_tex("\\neg"))
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)
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self.remove(neg_sym)
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# Recall final answer
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diagram.add(
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diagram.h_brace,
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diagram.he_brace,
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diagram.nhe_brace,
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)
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self.play(
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diagram.scale, 0.7, {"about_edge": DL},
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diagram.refresh_braces,
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MaintainPositionRelativeTo(
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VGroup(like_word, like_arrow),
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like_label,
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),
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MaintainPositionRelativeTo(
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VGroup(prior_word, prior_arrow),
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prior_label,
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),
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)
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def get_diagram(self):
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diagram = BayesDiagram(
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prior=1 / 21,
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likelihood=0.4,
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antilikelihood=0.1,
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not_evidence_color1=GREY,
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not_evidence_color2=DARK_GREY,
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prior_rect_direction=UP,
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)
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diagram.set_height(5.5)
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diagram.set_width(6, stretch=True)
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diagram.move_to(0.5 * DOWN)
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diagram.add_brace_attrs()
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diagram.evidence_split.set_opacity(0)
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diagram.hypothesis_split.set_opacity(0)
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diagram.nh_rect.set_fill(DARK_GREY)
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people = VGroup(*[Person() for x in range(210)])
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people.set_color(interpolate_color(LIGHT_GREY, WHITE, 0.5))
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people.arrange_in_grid(n_cols=21)
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people.set_width(diagram.get_width() - SMALL_BUFF)
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people.set_height(diagram.get_height() - SMALL_BUFF, stretch=True)
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people.move_to(diagram)
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people[10:].set_color(GREEN_D)
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people.set_stroke(BLACK, 2, background=True)
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diagram.add(people)
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diagram.people = people
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return diagram
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Reference in New Issue
Block a user