Final animations for de chapter2

This commit is contained in:
Grant Sanderson
2019-04-21 08:15:11 -07:00
parent 3bdc57aac4
commit ee622987df
9 changed files with 2965 additions and 179 deletions

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@ -5,7 +5,7 @@ from active_projects.ode.part1.phase_space import *
from active_projects.ode.part1.wordy_scenes import *
OUTPUT_DIRECTORY = "ode/part1"
ALL_SCENE_CLASSES = [
SCENES_IN_ORDER = [
WhenChangeIsEasier,
VectorFieldTest,
IntroducePendulum,

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@ -5,33 +5,24 @@ from active_projects.ode.part2.pi_scenes import *
from active_projects.ode.part2.wordy_scenes import *
OUTPUT_DIRECTORY = "ode/part2"
ALL_SCENE_CLASSES = [
# Tests
FourierOfPiSymbol,
FourierOfPiSymbol5,
FourierOfTrebleClef,
FourierOfEighthNote,
FourierOfN,
FourierNailAndGear,
FourierNDQ,
FourierBatman,
FourierGoogleG,
FourierHeart,
# CirclesDrawingWave,
# Scenes for video
ExplainCircleAnimations,
FourierSeriesIntroBackground4,
FourierSeriesIntroBackground8,
FourierSeriesIntroBackground12,
FourierSeriesIntroBackground20,
FourierSeriesIntro,
SCENES_IN_ORDER = [
PartTwoOfTour,
HeatEquationIntroTitle,
BrownianMotion,
BlackScholes,
ContrastChapters1And2,
FourierSeriesIntro,
FourierSeriesIntroBackground20,
ExplainCircleAnimations,
# FourierSeriesIntroBackground4,
# FourierSeriesIntroBackground8,
# FourierSeriesIntroBackground12,
TwoDBodyWithManyTemperatures,
TwoDBodyWithManyTemperaturesGraph,
TwoDBodyWithManyTemperaturesContour,
BringTwoRodsTogether,
ShowEvolvingTempGraphWithArrows,
TodaysTargetWrapper,
# TodaysTargetWrapper,
WriteHeatEquation,
ReactionsToInitialHeatEquation,
TalkThrough1DHeatGraph,
@ -39,8 +30,12 @@ ALL_SCENE_CLASSES = [
CompareInputsOfGeneralCaseTo1D,
ContrastXChangesToTChanges,
ShowPartialDerivativeSymbols,
WriteHeatEquation,
ShowCurvatureToRateOfChangeIntuition,
ContrastPDEToODE,
TransitionToTempVsTime,
ShowNewton,
ShowCupOfWater,
ShowNewtonsLawGraph,
Show1DAnd3DEquations,
#
AskAboutWhereEquationComesFrom,
DiscreteSetup,
]

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@ -108,6 +108,7 @@ class TourOfDifferentialEquations(MovingCameraScene):
def construct(self):
self.add_title()
self.show_thumbnails()
self.zoom_in_to_one_thumbnail()
# self.show_words()
def add_title(self):
@ -166,9 +167,13 @@ class TourOfDifferentialEquations(MovingCameraScene):
)
self.play(Write(dots))
self.wait()
self.thumbnails = thumbnails
def zoom_in_to_one_thumbnail(self):
self.play(
self.camera_frame.replace,
thumbnails[self.zoomed_thumbnail_index],
self.thumbnails[self.zoomed_thumbnail_index],
run_time=3,
)
self.wait()

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@ -185,7 +185,7 @@ class ReasonForSolution(Scene):
cu_group.arrange(DOWN, buff=2)
group = VGroup(eq_word, s_word, cu_group)
group.arrange(RIGHT, buff=2)
words = VGroup(eq_word, s_word, u_word, c_word)
# words = VGroup(eq_word, s_word, u_word, c_word)
# Arrows
arrows = VGroup(

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@ -367,6 +367,33 @@ class FourierOfTrebleClef(FourierOfPiSymbol):
return path
class FourierOfIP(FourierOfTrebleClef):
CONFIG = {
"file_name": "IP_logo2",
"height": 6,
"n_circles": 100,
}
# def construct(self):
# path = self.get_path()
# self.add(path)
def get_shape(self):
shape = SVGMobject(self.file_name)
return shape
def get_path(self):
shape = self.get_shape()
path = shape.family_members_with_points()[0]
path.add_line_to(path.get_start())
# path.make_smooth()
path.set_height(self.height)
path.set_fill(opacity=0)
path.set_stroke(WHITE, 0)
return path
class FourierOfEighthNote(FourierOfTrebleClef):
CONFIG = {
"file_name": "EighthNote"

File diff suppressed because it is too large Load Diff

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@ -1,4 +1,5 @@
from big_ol_pile_of_manim_imports import *
from active_projects.ode.part2.wordy_scenes import WriteHeatEquationTemplate
class ReactionsToInitialHeatEquation(PiCreatureScene):
@ -19,5 +20,123 @@ class ReactionsToInitialHeatEquation(PiCreatureScene):
point.next_to, randy, UR, LARGE_BUFF,
)
self.wait(2)
self.play(point.shift, 2 * DOWN)
self.play(
point.shift, 2 * DOWN,
randy.change, "horrified"
)
self.wait(4)
class ContrastPDEToODE(TeacherStudentsScene):
CONFIG = {
"random_seed": 2,
}
def construct(self):
student = self.students[2]
pde, ode = words = VGroup(*[
TextMobject(
text + "\\\\",
"Differential\\\\",
"Equation"
)
for text in ("Partial", "Ordinary")
])
pde[0].set_color(YELLOW)
ode[0].set_color(BLUE)
for word in words:
word.arrange(DOWN, aligned_edge=LEFT)
words.arrange(RIGHT, buff=LARGE_BUFF)
words.next_to(student.get_corner(UR), UP, MED_LARGE_BUFF)
words.shift(UR)
lt = TexMobject("<")
lt.scale(1.5)
lt.move_to(Line(pde.get_right(), ode.get_left()))
for pi in self.pi_creatures:
pi.add_updater(lambda p: p.look_at(pde))
self.play(
FadeInFromDown(VGroup(words, lt)),
student.change, "raise_right_hand",
)
self.play(
self.get_student_changes("pondering", "pondering", "hooray"),
self.teacher.change, "happy"
)
self.wait(3)
self.play(
Swap(ode, pde),
self.teacher.change, "raise_right_hand",
self.get_student_changes(
"erm", "sassy", "confused"
)
)
self.look_at(words)
self.change_student_modes(
"thinking", "thinking", "tease",
)
self.wait(3)
class AskAboutWhereEquationComesFrom(TeacherStudentsScene, WriteHeatEquationTemplate):
def construct(self):
equation = self.get_d1_equation()
equation.move_to(self.hold_up_spot, DOWN)
self.play(
FadeInFromDown(equation),
self.teacher.change, "raise_right_hand"
)
self.student_says(
"Um...why?",
target_mode="sassy",
student_index=2,
bubble_kwargs={"direction": RIGHT},
)
self.change_student_modes(
"confused", "confused", "sassy",
)
self.wait()
self.play(
self.teacher.change, "pondering",
)
self.wait(2)
class AskWhyRewriteIt(TeacherStudentsScene):
def construct(self):
self.student_says(
"Why?", student_index=1,
bubble_kwargs={"height": 2, "width": 2},
)
self.students[1].bubble = None
self.teacher_says(
"One step closer\\\\to derivatives"
)
self.change_student_modes(
"thinking", "thinking", "thinking",
look_at_arg=4 * LEFT + 2 * UP
)
self.wait(2)
class ReferenceKhanVideo(TeacherStudentsScene):
def construct(self):
khan_logo = ImageMobject("KhanLogo")
khan_logo.set_height(1)
khan_logo.next_to(self.teacher, UP, buff=2)
khan_logo.shift(2 * LEFT)
self.play(
self.teacher.change, "raise_right_hand",
)
self.change_student_modes(
"thinking", "pondering", "thinking",
look_at_arg=self.screen
)
self.wait()
self.play(FadeInFromDown(khan_logo))
self.look_at(self.screen)
self.wait(15)

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@ -2,92 +2,376 @@ from big_ol_pile_of_manim_imports import *
from active_projects.ode.part1.staging import TourOfDifferentialEquations
class FourierSeriesIntro(Scene):
def construct(self):
title_scale_value = 1.5
title = TextMobject(
"Fourier ", "Series",
)
title.scale(title_scale_value)
title.to_edge(UP)
title.generate_target()
details_coming = TextMobject("Details coming...")
details_coming.next_to(title.get_corner(DR), DOWN)
details_coming.set_color(LIGHT_GREY)
physics = TextMobject("Physics")
physics.scale(title_scale_value)
arrow = Arrow(LEFT, RIGHT)
group = VGroup(physics, arrow, title.target)
group.arrange(RIGHT)
physics.align_to(title.target, UP)
group.to_edge(UP)
rot_square = Square()
rot_square.fade(1)
rot_square.add_updater(lambda m, dt: m.rotate(dt))
heat = TextMobject("Heat")
heat.scale(title_scale_value)
heat.move_to(physics[0][-1], DR)
def update_heat_colors(heat):
vertices = rot_square.get_vertices()
letters = heat.family_members_with_points()
for letter, vertex in zip(letters, vertices):
alpha = (normalize(vertex)[0] + 1) / 2
letter.set_color(interpolate_color(
YELLOW, RED, alpha,
))
heat.add_updater(update_heat_colors)
image = ImageMobject("Joseph Fourier")
image.set_height(5)
image.next_to(title, DOWN, MED_LARGE_BUFF)
image.to_edge(LEFT)
name = TextMobject("Joseph", "Fourier")
name.next_to(image, DOWN)
# self.play(FadeInFromDown(title))
self.add(title)
self.play(
FadeInFromDown(image),
TransformFromCopy(
title.get_part_by_tex("Fourier"),
name.get_part_by_tex("Fourier"),
path_arc=90 * DEGREES,
),
FadeIn(name.get_part_by_tex("Joseph")),
)
self.play(Write(details_coming, run_time=1))
self.play(LaggedStartMap(FadeOut, details_coming[0], run_time=1))
self.wait()
self.play(
FadeInFrom(physics, RIGHT),
GrowArrow(arrow),
MoveToTarget(title)
)
self.wait()
self.add(rot_square)
self.play(
FadeOutAndShift(physics, UP),
FadeInFromDown(heat, DOWN),
)
self.wait(10)
class PartTwoOfTour(TourOfDifferentialEquations):
CONFIG = {
"zoomed_thumbnail_index": 1,
}
def construct(self):
self.add_title()
self.show_thumbnails()
self.zoom_in_to_one_thumbnail()
def zoom_in_to_one_thumbnail(self):
frame = self.camera_frame
thumbnails = self.thumbnails
ode = TextMobject("Ordinary\\\\", "Differential Equation")
pde = TextMobject("Partial\\\\", "Differential Equation")
for word, thumbnail, vect in zip([ode, pde], thumbnails, [DOWN, UP]):
word.match_width(thumbnail)
word.next_to(thumbnail, vect)
ode[0].set_color(BLUE)
pde[0].set_color(YELLOW)
self.add(ode)
frame.save_state()
self.play(
frame.replace,
thumbnails[0],
run_time=1,
)
self.play(
Restore(frame, run_time=3),
)
self.play(
TransformFromCopy(ode, pde),
)
self.play(
ApplyMethod(
frame.replace, thumbnails[1],
path_arc=(-30 * DEGREES),
run_time=3
),
)
self.wait()
class BrownianMotion(Scene):
CONFIG = {
"wait_time": 60,
"L": 3, # Box in [-L, L] x [-L, L]
"n_particles": 100,
"m1": 1,
"m2": 100,
"r1": 0.05,
"r2": 0.5,
"max_v": 5,
"random_seed": 2,
}
def construct(self):
self.add_title()
self.add_particles()
self.wait(self.wait_time)
def add_title(self):
square = Square(side_length=2 * self.L)
title = TextMobject("Brownian motion")
title.scale(1.5)
title.next_to(square, UP)
self.add(square)
self.add(title)
def add_particles(self):
m1 = self.m1
m2 = self.m2
r1 = self.r1
r2 = self.r2
L = self.L
max_v = self.max_v
n_particles = self.n_particles
lil_particles = VGroup(*[
self.get_particle(m1, r1, L, max_v)
for k in range(n_particles)
])
big_particle = self.get_particle(m2, r2, L=r2, max_v=0)
big_particle.set_fill(YELLOW, 1)
for p in lil_particles:
if self.are_colliding(p, big_particle):
lil_particles.remove(p)
all_particles = VGroup(big_particle, *lil_particles)
all_particles.add_updater(self.update_particles)
path = self.get_traced_path(big_particle)
self.add(all_particles)
self.add(path)
self.particles = all_particles
self.big_particle = big_particle
self.path = path
def get_particle(self, m, r, L, max_v):
dot = Dot(radius=r)
dot.set_fill(WHITE, 0.7)
dot.mass = m
dot.radius = r
dot.center = op.add(
np.random.uniform(-L + r, L - r) * RIGHT,
np.random.uniform(-L + r, L - r) * UP
)
dot.move_to(dot.center)
dot.velocity = rotate_vector(
np.random.uniform(0, max_v) * RIGHT,
np.random.uniform(0, TAU),
)
return dot
def are_colliding(self, p1, p2):
d = get_norm(p1.get_center() - p2.get_center())
return (d < p1.radius + p2.radius)
def get_traced_path(self, particle):
path = VMobject()
path.set_stroke(BLUE, 3)
path.start_new_path(particle.get_center())
buff = 0.02
def update_path(path):
new_point = particle.get_center()
if get_norm(new_point - path.get_last_point()) > buff:
path.add_line_to(new_point)
path.add_updater(update_path)
return path
def update_particles(self, particles, dt):
for p1 in particles:
p1.center += p1.velocity * dt
# Check particle collisions
buff = 0.01
for p2 in particles:
if p1 is p2:
continue
v = p2.center - p1.center
dist = get_norm(v)
r_sum = p1.radius + p2.radius
diff = dist - r_sum
if diff < 0:
unit_v = v / dist
p1.center += (diff - buff) * unit_v / 2
p2.center += -(diff - buff) * unit_v / 2
u1 = p1.velocity
u2 = p2.velocity
m1 = p1.mass
m2 = p2.mass
v1 = (
(m2 * (u2 - u1) + m1 * u1 + m2 * u2) /
(m1 + m2)
)
v2 = (
(m1 * (u1 - u2) + m1 * u1 + m2 * u2) /
(m1 + m2)
)
p1.velocity = v1
p2.velocity = v2
# Check edge collisions
r1 = p1.radius
c1 = p1.center
for i in [0, 1]:
if abs(c1[i]) + r1 > self.L:
c1[i] = np.sign(c1[i]) * (self.L - r1)
p1.velocity[i] *= -1 * op.mul(
np.sign(p1.velocity[i]),
np.sign(c1[i])
)
for p in particles:
p.move_to(p.center)
return particles
class AltBrownianMotion(BrownianMotion):
CONFIG = {
"wait_time": 20,
"n_particles": 100,
"m2": 10,
}
class BlackScholes(AltBrownianMotion):
def construct(self):
# For some reason I'm amused by the thought
# Of this graph perfectly matching the Brownian
# Motion y-coordiante
self.add_title()
self.add_particles()
self.particles.set_opacity(0)
self.remove(self.path)
self.add_graph()
self.wait(self.wait_time)
def add_title(self):
title = TextMobject("Black-Sholes equations")
title.scale(1.5)
title.next_to(2 * UP, UP)
equation = TexMobject(
"{\\partial V \\over \\partial t}", "+",
"\\frac{1}{2} \\sigma^2 S^2",
"{\\partial^2 V \\over \\partial S^2}", "+",
"rS", "{\\partial V \\over \\partial S}",
"-rV", "=", "0",
)
equation.scale(0.8)
equation.next_to(title, DOWN)
self.add(title)
self.add(equation)
self.title = title
self.equation = equation
def add_graph(self):
axes = Axes(
x_min=-1,
x_max=20,
y_min=0,
y_max=10,
number_line_config={
"unit_size": 0.5,
},
)
axes.set_height(4)
axes.move_to(DOWN)
def get_graph_point():
return axes.c2p(
self.get_time(),
5 + 2 * self.big_particle.get_center()[1]
)
graph = VMobject()
graph.match_style(self.path)
graph.start_new_path(get_graph_point())
graph.add_updater(
lambda g: g.add_line_to(get_graph_point())
)
self.add(axes)
self.add(graph)
class ContrastChapters1And2(Scene):
def construct(self):
c1_frame, c2_frame = frames = VGroup(*[
ScreenRectangle(height=3.5)
for x in range(2)
])
frames.arrange(RIGHT, buff=LARGE_BUFF)
c1_title, c2_title = titles = VGroup(
TextMobject("Chapter 1"),
TextMobject("Chapter 2"),
)
titles.scale(1.5)
ode, pde = des = VGroup(
TextMobject(
"Ordinary",
"Differential Equations\\\\",
"ODEs",
),
TextMobject(
"Partial",
"Differential Equations\\\\",
"PDEs",
),
)
ode[0].set_color(BLUE)
pde[0].set_color(YELLOW)
for de in des:
de[-1][0].match_color(de[0])
de[-1].scale(1.5, about_point=de.get_top())
for title, frame, de in zip(titles, frames, des):
title.next_to(frame, UP)
de.match_width(frame)
de.next_to(frame, DOWN)
lt = TexMobject("<")
lt.move_to(Line(ode.get_right(), pde.get_left()))
lt.scale(2, about_edge=UP)
c1_words = TextMobject(
"They're", "really\\\\", "{}",
"freaking", "hard\\\\",
"to", "solve\\\\",
)
c1_words.set_height(0.5 * c1_frame.get_height())
c1_words.move_to(c1_frame)
c2_words = TextMobject(
"They're", "really", "\\emph{really}\\\\",
"freaking", "hard\\\\",
"to", "solve\\\\",
)
c2_words.set_color_by_tex("\\emph", YELLOW)
c2_words.move_to(c2_frame)
edit_shift = MED_LARGE_BUFF * RIGHT
c2_edits = VGroup(
TextMobject("sometimes").next_to(
c2_words[1:3], UP,
aligned_edge=LEFT,
),
Line(
c2_words[1].get_left(),
c2_words[2].get_right(),
stroke_width=8,
),
TextMobject("not too").next_to(
c2_words[3], LEFT,
),
Line(
c2_words[3].get_left(),
c2_words[3].get_right(),
stroke_width=8,
),
)
c2_edits.set_color(RED)
c2_edits[2:].shift(edit_shift)
self.add(titles)
self.add(frames)
self.add(des)
self.wait()
self.play(LaggedStartMap(
FadeInFromDown, c1_words,
lag_ratio=0.1,
))
self.wait()
# self.play(FadeIn(ode))
self.play(
# TransformFromCopy(ode, pde),
TransformFromCopy(c1_words, c2_words),
Write(lt)
)
self.wait()
self.play(
Write(c2_edits[:2], run_time=1),
)
self.play(
c2_words[3:5].shift, edit_shift,
Write(c2_edits[2:]),
run_time=1,
)
self.wait()
class ShowCubeFormation(ThreeDScene):
CONFIG = {
"camera_config": {
"shading_factor": 1.0,
}
},
"color": False,
}
def construct(self):
@ -101,6 +385,12 @@ class ShowCubeFormation(ThreeDScene):
stroke_width=0.5,
)
cube.set_fill(opacity=1)
if self.color:
# cube[0].set_color(BLUE)
# cube[1].set_color(RED)
# for face in cube[2:]:
# face.set_color([BLUE, RED])
cube.color_using_background_image("VerticalTempGradient")
# light_source.next_to(cube, np.array([1, -1, 1]), buff=2)
@ -121,7 +411,341 @@ class ShowCubeFormation(ThreeDScene):
self.play(
Transform(cube, target, run_time=1.5)
)
self.wait(8)
class ShowCubeFormationWithColor(ShowCubeFormation):
CONFIG = {
"color": True,
}
class ShowRect(Scene):
CONFIG = {
"height": 1,
"width": 3,
}
def construct(self):
rect = Rectangle(
height=self.height,
width=self.width,
)
rect.set_color(YELLOW)
self.play(ShowCreationThenFadeOut(rect))
class ShowSquare(ShowRect):
CONFIG = {
"height": 1,
"width": 1,
}
class ShowHLine(Scene):
def construct(self):
line = Line(LEFT, RIGHT)
line.set_color(BLUE)
self.play(ShowCreationThenFadeOut(line))
class ShowCross(Scene):
def construct(self):
cross = Cross(Square())
cross.set_width(3)
cross.set_height(1, stretch=True)
self.play(ShowCreation(cross))
class TwoBodyEquations(Scene):
def construct(self):
kw = {
"tex_to_color_map": {
"x_1": LIGHT_GREY,
"y_1": LIGHT_GREY,
"x_2": BLUE,
"y_2": BLUE,
"=": WHITE,
}
}
equations = VGroup(
TexMobject(
"{d^2 x_1 \\over dt^2}",
"=",
"{x_2 - x_1 \\over m_1 \\left(",
"(x_2 - x_1)^2 + (y_2 - y_1)^2",
"\\right)^{3/2}",
**kw
),
TexMobject(
"{d^2 y_1 \\over dt^2}",
"=",
"{y_2 - y_1 \\over m_1 \\left(",
"(x_2 - x_1)^2 + (y_2 - y_1)^2",
"\\right)^{3/2}",
**kw
),
TexMobject(
"{d^2 x_2 \\over dt^2}",
"=",
"{x_1 - x_2 \\over m_2 \\left(",
"(x_2 - x_1)^2 + (y_2 - y_1)^2",
"\\right)^{3/2}",
**kw
),
TexMobject(
"{d^2 y_2 \\over dt^2}",
"=",
"{y_1 - y_2 \\over m_2 \\left(",
"(x_2 - x_1)^2 + (y_2 - y_1)^2",
"\\right)^{3/2}",
**kw
),
)
equations.arrange(DOWN, buff=LARGE_BUFF)
equations.set_height(6)
equations.to_edge(LEFT)
variables = VGroup()
lhss = VGroup()
rhss = VGroup()
for equation in equations:
variable = equation[1]
lhs = equation[:4]
rhs = equation[4:]
variables.add(variable)
lhss.add(lhs)
rhss.add(rhs)
lhss_copy = lhss.copy()
for variable, lhs in zip(variables, lhss):
variable.save_state()
variable.match_height(lhs)
variable.scale(0.7)
variable.move_to(lhs, LEFT)
self.play(LaggedStart(*[
FadeInFrom(v, RIGHT)
for v in variables
]))
self.wait()
self.play(
LaggedStartMap(Restore, variables),
FadeIn(
lhss_copy,
remover=True,
lag_ratio=0.1,
run_time=2,
)
)
self.add(lhss)
self.wait()
self.play(LaggedStartMap(
FadeIn, rhss
))
self.wait()
self.play(
LaggedStart(*[
ShowCreationThenFadeAround(lhs[:3])
for lhs in lhss
])
)
self.wait()
self.play(
LaggedStartMap(
ShowCreationThenFadeAround,
rhss,
)
)
self.wait()
class LaplacianIntuition(SpecialThreeDScene):
CONFIG = {
"three_d_axes_config": {
"x_min": -5,
"x_max": 5,
"y_min": -5,
"y_max": 5,
},
"surface_resolution": 32,
}
def construct(self):
axes = self.get_axes()
axes.scale(0.5, about_point=ORIGIN)
self.set_camera_to_default_position()
self.begin_ambient_camera_rotation()
def func(x, y):
return np.array([
x, y,
2.7 + 0.5 * (np.sin(x) + np.cos(y)) -
0.025 * (x**2 + y**2)
])
surface_config = {
"u_min": -5,
"u_max": 5,
"v_min": -5,
"v_max": 5,
"resolution": self.surface_resolution,
}
# plane = ParametricSurface(
# lambda u, v: np.array([u, v, 0]),
# **surface_config
# )
# plane.set_stroke(WHITE, width=0.1)
# plane.set_fill(WHITE, opacity=0.1)
plane = Square(
side_length=10,
stroke_width=0,
fill_color=WHITE,
fill_opacity=0.1,
)
plane.center()
plane.set_shade_in_3d(True)
surface = ParametricSurface(
func, **surface_config
)
surface.set_stroke(BLUE, width=0.1)
surface.set_fill(BLUE, opacity=0.25)
self.add(axes, plane, surface)
point = VectorizedPoint(np.array([2, -2, 0]))
dot = Dot()
dot.set_color(GREEN)
dot.add_updater(lambda d: d.move_to(point))
line = always_redraw(lambda: DashedLine(
point.get_location(),
func(*point.get_location()[:2]),
background_image_file="VerticalTempGradient",
))
circle = Circle(radius=0.25)
circle.set_color(YELLOW)
circle.insert_n_curves(20)
circle.add_updater(lambda m: m.move_to(point))
circle.set_shade_in_3d(True)
surface_circle = always_redraw(
lambda: circle.copy().apply_function(
lambda p: func(*p[:2])
).shift(
0.02 * IN
).color_using_background_image("VerticalTempGradient")
)
self.play(FadeInFromLarge(dot))
self.play(ShowCreation(line))
self.play(TransformFromCopy(dot, circle))
self.play(
Transform(
circle.copy(),
surface_circle.copy().clear_updaters(),
remover=True,
)
)
self.add(surface_circle)
self.wait()
for vect in [4 * LEFT, DOWN, 4 * RIGHT, UP]:
self.play(
point.shift, vect,
run_time=3,
)
class StrogatzMention(PiCreatureScene):
def construct(self):
self.show_book()
self.show_motives()
self.show_pages()
def show_book(self):
morty = self.pi_creature
book = ImageMobject("InfinitePowers")
book.set_height(5)
book.to_edge(LEFT)
steve = ImageMobject("Strogatz_by_bricks")
steve.set_height(5)
steve.to_edge(LEFT)
name = TextMobject("Steven Strogatz")
name.match_width(steve)
name.next_to(steve, DOWN)
self.think(
"Hmm...many good\\\\lessons here...",
run_time=1
)
self.wait()
self.play(FadeInFromDown(steve))
self.wait()
self.play(
FadeInFrom(book, DOWN),
steve.shift, 4 * RIGHT,
RemovePiCreatureBubble(
morty, target_mode="thinking"
)
)
self.wait(3)
self.play(
FadeOut(steve),
FadeOut(morty),
)
self.book = book
def show_motives(self):
motives = VGroup(
TextMobject("1) Scratch and itch"),
TextMobject("2) Make people love math"),
)
motives.scale(1.5)
motives.arrange(
DOWN, LARGE_BUFF,
aligned_edge=LEFT,
)
motives.move_to(
Line(
self.book.get_right(),
FRAME_WIDTH * RIGHT / 2
)
)
motives.to_edge(UP)
for motive in motives:
self.play(FadeInFromDown(motive))
self.wait(2)
self.play(FadeOut(motives))
def show_pages(self):
book = self.book
pages = Group(*[
ImageMobject("IP_Sample_Page{}".format(i))
for i in range(1, 4)
])
for page in pages:
page.match_height(book)
page.next_to(book, RIGHT)
last_page = VectorizedPoint()
for page in pages:
self.play(
FadeOut(last_page),
FadeIn(page)
)
self.wait()
last_page = page
self.play(FadeOut(last_page))
def create_pi_creature(self):
return Mortimer().to_corner(DR)
class ShowNewton(Scene):

View File

@ -1,6 +1,222 @@
from big_ol_pile_of_manim_imports import *
class WriteHeatEquationTemplate(Scene):
CONFIG = {
"tex_mobject_config": {
"tex_to_color_map": {
"{T}": WHITE,
"{t}": YELLOW,
"{x}": GREEN,
"{y}": RED,
"{z}": BLUE,
"\\partial": WHITE,
"2": WHITE,
},
},
}
def get_d1_equation(self):
return TexMobject(
"{\\partial {T} \\over \\partial {t}}({x}, {t})", "=",
"\\alpha \\cdot",
"{\\partial^2 {T} \\over \\partial {x}^2} ({x}, {t})",
**self.tex_mobject_config
)
def get_d1_equation_without_inputs(self):
return TexMobject(
"{\\partial {T} \\over \\partial {t}}", "=",
"\\alpha \\cdot",
"{\\partial^2 {T} \\over \\partial {x}^2}",
**self.tex_mobject_config
)
def get_d3_equation(self):
return TexMobject(
"{\\partial {T} \\over \\partial {t}}", "=",
"\\alpha \\left(",
"{\\partial^2 {T} \\over \\partial {x}^2} + ",
"{\\partial^2 {T} \\over \\partial {y}^2} + ",
"{\\partial^2 {T} \\over \\partial {z}^2}",
"\\right)",
**self.tex_mobject_config
)
def get_general_equation(self):
return TexMobject(
"{\\partial {T} \\over \\partial {t}}", "=",
"\\alpha", "\\nabla^2 {T}",
**self.tex_mobject_config,
)
def get_d3_equation_with_inputs(self):
return TexMobject(
"{\\partial {T} \\over \\partial {t}}",
"({x}, {y}, {z}, {t})", "=",
"\\alpha \\left(",
"{\\partial^2 {T} \\over \\partial {x}^2}",
"({x}, {y}, {z}, {t}) + ",
"{\\partial^2 {T} \\over \\partial {y}^2}",
"({x}, {y}, {z}, {t}) + ",
"{\\partial^2 {T} \\over \\partial {z}^2}",
"({x}, {y}, {z}, {t})",
"\\right)",
**self.tex_mobject_config
)
def get_d1_words(self):
return TextMobject("Heat equation\\\\", "(1 dimension)")
def get_d3_words(self):
return TextMobject("Heat equation\\\\", "(3 dimensions)")
def get_d1_group(self):
group = VGroup(
self.get_d1_words(),
self.get_d1_equation(),
)
group.arrange(DOWN, buff=MED_LARGE_BUFF)
return group
def get_d3_group(self):
group = VGroup(
self.get_d3_words(),
self.get_d3_equation(),
)
group.arrange(DOWN, buff=MED_LARGE_BUFF)
return group
class HeatEquationIntroTitle(WriteHeatEquationTemplate):
def construct(self):
scale_factor = 1.25
title = TextMobject("The Heat Equation")
title.scale(scale_factor)
title.to_edge(UP)
equation = self.get_general_equation()
equation.scale(scale_factor)
equation.next_to(title, DOWN, MED_LARGE_BUFF)
equation.set_color_by_tex("{T}", RED)
self.play(
FadeInFrom(title, DOWN),
FadeInFrom(equation, UP),
)
self.wait()
class BringTogether(Scene):
def construct(self):
arrows = VGroup(Vector(2 * RIGHT), Vector(2 * LEFT))
arrows.arrange(RIGHT, buff=2)
words = TextMobject("Bring together")[0]
words.next_to(arrows, DOWN)
words.save_state()
words.space_out_submobjects(1.2)
self.play(
VFadeIn(words),
Restore(words),
arrows.arrange, RIGHT, {"buff": SMALL_BUFF},
VFadeIn(arrows),
)
self.play(FadeOut(words), FadeOut(arrows))
class FourierSeriesIntro(WriteHeatEquationTemplate):
def construct(self):
title_scale_value = 1.5
title = TextMobject(
"Fourier ", "Series",
)
title.scale(title_scale_value)
title.to_edge(UP)
title.generate_target()
details_coming = TextMobject("Details coming...")
details_coming.next_to(title.get_corner(DR), DOWN)
details_coming.set_color(LIGHT_GREY)
# physics = TextMobject("Physics")
heat = TextMobject("Heat")
heat.scale(title_scale_value)
physics = self.get_general_equation()
physics.set_color_by_tex("{T}", RED)
arrow1 = Arrow(LEFT, RIGHT)
arrow2 = Arrow(LEFT, RIGHT)
group = VGroup(
heat, arrow1, physics, arrow2, title.target
)
group.arrange(RIGHT)
# physics.align_to(title.target, UP)
group.to_edge(UP)
rot_square = Square()
rot_square.fade(1)
rot_square.add_updater(lambda m, dt: m.rotate(dt))
def update_heat_colors(heat):
colors = [YELLOW, RED]
vertices = rot_square.get_vertices()
letters = heat.family_members_with_points()
for letter, vertex in zip(letters, vertices):
alpha = (normalize(vertex)[0] + 1) / 2
i, sa = integer_interpolate(0, len(colors) - 1, alpha)
letter.set_color(interpolate_color(
colors[i], colors[i + 1], alpha,
))
heat.add_updater(update_heat_colors)
image = ImageMobject("Joseph Fourier")
image.set_height(5)
image.next_to(title, DOWN, LARGE_BUFF)
image.to_edge(LEFT)
name = TextMobject("Joseph", "Fourier")
name.next_to(image, DOWN)
bubble = ThoughtBubble(
height=2,
width=2.5,
direction=RIGHT,
)
bubble.set_fill(opacity=0)
bubble.set_stroke(WHITE)
bubble.set_stroke(BLACK, 5, background=True)
bubble.shift(heat.get_center() - bubble.get_bubble_center())
bubble[:-1].shift(LEFT + 0.2 * DOWN)
bubble[:-1].rotate(-20 * DEGREES)
for mob in bubble[:-1]:
mob.rotate(20 * DEGREES)
# self.play(FadeInFromDown(title))
self.add(title)
self.play(
FadeInFromDown(image),
TransformFromCopy(
title.get_part_by_tex("Fourier"),
name.get_part_by_tex("Fourier"),
path_arc=90 * DEGREES,
),
FadeIn(name.get_part_by_tex("Joseph")),
)
self.play(Write(details_coming, run_time=1))
self.play(LaggedStartMap(FadeOut, details_coming[0], run_time=1))
self.wait()
self.add(rot_square)
self.play(
FadeInFrom(physics, RIGHT),
GrowArrow(arrow2),
FadeInFrom(heat, RIGHT),
GrowArrow(arrow1),
MoveToTarget(title),
)
self.play(ShowCreation(bubble))
self.wait(10)
class CompareODEToPDE(Scene):
def construct(self):
pass
@ -11,11 +227,33 @@ class TodaysTargetWrapper(Scene):
pass
class TwoGraphTypeTitles(Scene):
def construct(self):
left_title = TextMobject(
"Represent time\\\\with actual time"
)
left_title.shift(FRAME_WIDTH * LEFT / 4)
right_title = TextMobject(
"Represent time\\\\with an axis"
)
right_title.shift(FRAME_WIDTH * RIGHT / 4)
titles = VGroup(left_title, right_title)
for title in titles:
title.scale(1.25)
title.to_edge(UP)
self.play(FadeInFromDown(right_title))
self.wait()
self.play(FadeInFromDown(left_title))
self.wait()
class ShowPartialDerivativeSymbols(Scene):
def construct(self):
t2c = {
"{x}": GREEN,
"{t}": PINK,
"{t}": YELLOW,
}
d_derivs, del_derivs = VGroup(*[
VGroup(*[
@ -94,6 +332,7 @@ class ShowPartialDerivativeSymbols(Scene):
num,
buff=SMALL_BUFF,
stroke_width=2,
color=word[-1].get_color(),
)
deriv.rect.mob = num
deriv.rect.add_updater(lambda r: r.move_to(r.mob))
@ -110,19 +349,90 @@ class ShowPartialDerivativeSymbols(Scene):
self.wait()
class WriteHeatEquation(Scene):
CONFIG = {
"tex_mobject_config": {
"tex_to_color_map": {
"{T}": YELLOW,
"{t}": WHITE,
"{x}": GREEN,
"{y}": RED,
"{z}": BLUE,
},
},
}
class WriteHeatEquation(WriteHeatEquationTemplate):
def construct(self):
title = TextMobject("The Heat Equation")
title.to_edge(UP)
equation = self.get_d1_equation()
equation.next_to(title, DOWN)
eq_i = equation.index_of_part_by_tex("=")
dt_part = equation[:eq_i]
dx_part = equation[eq_i + 3:]
dt_rect = SurroundingRectangle(dt_part)
dt_rect.set_stroke(YELLOW, 2)
dx_rect = SurroundingRectangle(dx_part)
dx_rect.set_stroke(GREEN, 2)
two_outlines = equation.get_parts_by_tex("2").copy()
two_outlines.set_stroke(YELLOW, 2)
two_outlines.set_fill(opacity=0)
to_be_explained = TextMobject(
"To be explained shortly..."
)
to_be_explained.scale(0.7)
to_be_explained.next_to(equation, RIGHT, MED_LARGE_BUFF)
to_be_explained.fade(1)
pde = TextMobject("Partial Differential Equation")
pde.move_to(title)
del_outlines = equation.get_parts_by_tex("\\partial").copy()
del_outlines.set_stroke(YELLOW, 2)
del_outlines.set_fill(opacity=0)
self.play(
FadeInFrom(title, 0.5 * DOWN),
FadeInFrom(equation, 0.5 * UP),
)
self.wait()
self.play(ShowCreation(dt_rect))
self.wait()
self.play(TransformFromCopy(dt_rect, dx_rect))
self.play(ShowCreationThenDestruction(two_outlines))
self.wait()
self.play(Write(to_be_explained, run_time=1))
self.wait(2)
self.play(
ShowCreationThenDestruction(
del_outlines,
lag_ratio=0.1,
)
)
self.play(
FadeOutAndShift(title, UP),
FadeInFrom(pde, DOWN),
FadeOut(dt_rect),
FadeOut(dx_rect),
)
self.wait()
class Show3DEquation(WriteHeatEquationTemplate):
def construct(self):
equation = self.get_d3_equation_with_inputs()
equation.set_width(FRAME_WIDTH - 1)
inputs = VGroup(*it.chain(*[
equation.get_parts_by_tex(s)
for s in ["{x}", "{y}", "{z}", "{t}"]
]))
inputs.sort()
equation.to_edge(UP)
self.add(equation)
self.play(LaggedStartMap(
ShowCreationThenFadeAround, inputs,
surrounding_rectangle_config={
"buff": 0.05,
"stroke_width": 2,
}
))
self.wait()
class Show1DAnd3DEquations(WriteHeatEquationTemplate):
def construct(self):
d1_group = self.get_d1_group()
d3_group = self.get_d3_group()
@ -132,10 +442,10 @@ class WriteHeatEquation(Scene):
groups = VGroup(d1_group, d3_group)
for group in groups:
group.arrange(DOWN, buff=MED_LARGE_BUFF)
groups.arrange(RIGHT, buff=2)
groups.arrange(RIGHT, buff=1.5)
groups.to_edge(UP)
d3_rhs = d3_equation[6:]
d3_rhs = d3_equation[9:-2]
d3_brace = Brace(d3_rhs, DOWN)
nabla_words = TextMobject("Sometimes written as")
nabla_words.match_width(d3_brace)
@ -169,55 +479,31 @@ class WriteHeatEquation(Scene):
)
self.wait()
def get_d1_equation(self):
return TexMobject(
"{\\partial {T} \\over \\partial {t}}({x}, {t})="
"{\\partial^2 {T} \\over \\partial {x}^2} ({x}, {t})",
**self.tex_mobject_config
class D1EquationNoInputs(WriteHeatEquationTemplate):
def construct(self):
equation = self.get_d1_equation_without_inputs()
equation.to_edge(UP)
# i1 = equation.index_of_part_by_tex("\\partial")
# i2 = equation.index_of_part_by_tex("\\cdot")
# equation[i1:i1 + 2].set_color(RED)
# equation[i2 + 1:i2 + 6].set_color(RED)
equation.set_color_by_tex("{T}", RED)
self.add(equation)
class AltHeatRHS(Scene):
def construct(self):
formula = TexMobject(
"{\\alpha \\over 2}", "\\Big(",
"T({x} - 1, {t}) + T({x} + 1, {t})"
"\\Big)",
tex_to_color_map={
"{x}": GREEN,
"{t}": YELLOW,
}
)
def get_d3_equation(self):
return TexMobject(
"{\\partial {T} \\over \\partial {t}} = ",
"{\\partial^2 {T} \\over \\partial {x}^2} + ",
"{\\partial^2 {T} \\over \\partial {y}^2} + ",
"{\\partial^2 {T} \\over \\partial {z}^2}",
**self.tex_mobject_config
)
def get_d3_equation_with_inputs(self):
return TexMobject(
"{\\partial {T} \\over \\partial {t}} = ",
"{\\partial^2 {T} \\over \\partial {x}^2}",
"(x, y, z, t) + ",
"{\\partial^2 {T} \\over \\partial {y}^2}",
"(x, y, z, t) + ",
"{\\partial^2 {T} \\over \\partial {z}^2}",
"(x, y, z, t)",
**self.tex_mobject_config
)
def get_d1_words(self):
return TextMobject("Heat equation\\\\", "(1 dimension)")
def get_d3_words(self):
return TextMobject("Heat equation\\\\", "(3 dimensions)")
def get_d1_group(self):
group = VGroup(
self.get_d1_words(),
self.get_d1_equation(),
)
group.arrange(DOWN, buff=MED_LARGE_BUFF)
return group
def get_d3_group(self):
group = VGroup(
self.get_d3_words(),
self.get_d3_equation(),
)
group.arrange(DOWN, buff=MED_LARGE_BUFF)
return group
self.add(formula)
class CompareInputsOfGeneralCaseTo1D(WriteHeatEquation):
@ -252,3 +538,248 @@ class CompareInputsOfGeneralCaseTo1D(WriteHeatEquation):
three_d_expr[low:high].scale, 0,
)
self.wait()
class ShowLaplacian(WriteHeatEquation):
def construct(self):
equation = self.get_d3_equation()
equation.to_edge(UP, buff=MED_SMALL_BUFF)
parts = VGroup()
plusses = VGroup()
for char in "xyz":
index = equation.index_of_part_by_tex(
"{" + char + "}"
)
part = equation[index - 6:index + 3]
rect = SurroundingRectangle(part)
rect.match_color(equation[index])
parts.add(part)
part.rect = rect
if char in "yz":
plus = equation[index - 8]
part.plus = plus
plusses.add(plus)
lp = equation.get_part_by_tex("(")
rp = equation.get_part_by_tex(")")
for part in parts:
part.rp = rp.copy()
part.rp.next_to(part, RIGHT, SMALL_BUFF)
part.rp.align_to(lp, UP)
rp.become(parts[0].rp)
# Show new second derivatives
self.add(*equation)
self.remove(*plusses, *parts[1], *parts[2])
for part in parts[1:]:
self.play(
rp.become, part.rp,
FadeInFrom(part, LEFT),
Write(part.plus),
ShowCreation(part.rect),
)
self.play(
FadeOut(part.rect),
)
self.wait()
# Show laplacian
brace = Brace(parts, DOWN)
laplacian = TexMobject("\\nabla^2", "T")
laplacian.next_to(brace, DOWN)
laplacian_name = TextMobject(
"``Laplacian''"
)
laplacian_name.next_to(laplacian, DOWN)
T_parts = VGroup(*[part[3] for part in parts])
non_T_parts = VGroup(*[
VGroup(*part[:3], *part[4:])
for part in parts
])
self.play(GrowFromCenter(brace))
self.play(Write(laplacian_name))
self.play(
TransformFromCopy(non_T_parts, laplacian[0])
)
self.play(
TransformFromCopy(T_parts, laplacian[1])
)
self.wait(3)
class AskAboutActuallySolving(WriteHeatEquationTemplate):
def construct(self):
equation = self.get_d1_equation()
equation.center()
q1 = TextMobject("Solve for T?")
q1.next_to(equation, UP, LARGE_BUFF)
q2 = TextMobject("What does it \\emph{mean} to solve this?")
q2.next_to(equation, UP, LARGE_BUFF)
formula = TexMobject(
"T({x}, {t}) = \\sin\\big(a{x}\\big) e^{-\\alpha \\cdot a^2 {t}}",
tex_to_color_map={
"{x}": GREEN,
"{t}": YELLOW,
}
)
formula.next_to(equation, DOWN, LARGE_BUFF)
q3 = TextMobject("Is this it?")
arrow = Vector(LEFT, color=WHITE)
arrow.next_to(formula, RIGHT)
q3.next_to(arrow, RIGHT)
self.add(equation)
self.play(FadeInFromDown(q1))
self.wait()
self.play(
FadeInFromDown(q2),
q1.shift, 1.5 * UP,
)
self.play(FadeInFrom(formula, UP))
self.play(
GrowArrow(arrow),
FadeInFrom(q3, LEFT)
)
self.wait()
class PDEPatreonEndscreen(PatreonEndScreen):
CONFIG = {
"specific_patrons": [
"Juan Benet",
"Vassili Philippov",
"Burt Humburg",
"Matt Russell",
"Scott Gray",
"soekul",
"Tihan Seale",
"Richard Barthel",
"Ali Yahya",
"dave nicponski",
"Evan Phillips",
"Graham",
"Joseph Kelly",
"Kaustuv DeBiswas",
"LambdaLabs",
"Lukas Biewald",
"Mike Coleman",
"Peter Mcinerney",
"Quantopian",
"Roy Larson",
"Scott Walter, Ph.D.",
"Yana Chernobilsky",
"Yu Jun",
"Jordan Scales",
"D. Sivakumar",
"Lukas -krtek.net- Novy",
"John Shaughnessy",
"Britt Selvitelle",
"David Gow",
"J",
"Jonathan Wilson",
"Joseph John Cox",
"Magnus Dahlström",
"Randy C. Will",
"Ryan Atallah",
"Luc Ritchie",
"1stViewMaths",
"Adrian Robinson",
"Alexis Olson",
"Andreas Benjamin Brössel",
"Andrew Busey",
"Ankalagon",
"Antoine Bruguier",
"Antonio Juarez",
"Arjun Chakroborty",
"Art Ianuzzi",
"Awoo",
"Bernd Sing",
"Boris Veselinovich",
"Brian Staroselsky",
"Chad Hurst",
"Charles Southerland",
"Chris Connett",
"Christian Kaiser",
"Clark Gaebel",
"Cooper Jones",
"Danger Dai",
"Dave B",
"Dave Kester",
"David B. Hill",
"David Clark",
"DeathByShrimp",
"Delton Ding",
"eaglle",
"emptymachine",
"Eric Younge",
"Eryq Ouithaqueue",
"Federico Lebron",
"Giovanni Filippi",
"Hal Hildebrand",
"Hitoshi Yamauchi",
"Isaac Jeffrey Lee",
"j eduardo perez",
"Jacob Magnuson",
"Jameel Syed",
"Jason Hise",
"Jeff Linse",
"Jeff Straathof",
"John Griffith",
"John Haley",
"John V Wertheim",
"Jonathan Eppele",
"Kai-Siang Ang",
"Kanan Gill",
"L0j1k",
"Lee Beck",
"Lee Redden",
"Linh Tran",
"Ludwig Schubert",
"Magister Mugit",
"Mark B Bahu",
"Mark Heising",
"Martin Price",
"Mathias Jansson",
"Matt Langford",
"Matt Roveto",
"Matthew Bouchard",
"Matthew Cocke",
"Michael Faust",
"Michael Hardel",
"Mirik Gogri",
"Mustafa Mahdi",
"Márton Vaitkus",
"Nero Li",
"Nikita Lesnikov",
"Omar Zrien",
"Owen Campbell-Moore",
"Peter Ehrnstrom",
"RedAgent14",
"rehmi post",
"Richard Burgmann",
"Richard Comish",
"Ripta Pasay",
"Rish Kundalia",
"Robert Teed",
"Roobie",
"Ryan Williams",
"Sachit Nagpal",
"Solara570",
"Stevie Metke",
"Tal Einav",
"Ted Suzman",
"Thomas Tarler",
"Tom Fleming",
"Valeriy Skobelev",
"Xavier Bernard",
"Yavor Ivanov",
"Yaw Etse",
"YinYangBalance.Asia",
"Zach Cardwell",
],
}