Files
manim/active_projects/spirals.py
2019-09-19 13:39:02 -07:00

842 lines
24 KiB
Python

from manimlib.imports import *
import json
OUTPUT_DIRECTORY = "spirals"
INV_113_MOD_710 = 377 # Inverse of 113 mode 710
INV_7_MOD_44 = 19
def generate_prime_list(*args):
if len(args) == 1:
start, stop = 2, args[0]
elif len(args) == 2:
start, stop = args
start = max(start, 2)
else:
raise TypeError("generate_prime_list takes 1 or 2 arguments")
result = []
for n in range(start, stop):
include = True
for k in range(2, int(np.sqrt(n)) + 1):
if n % k == 0:
include = False
break
if include:
result.append(n)
return result
def get_gcd(x, y):
while y > 0:
x, y = y, x % y
return x
def read_in_primes(max_N=None):
with open(os.path.join("assets", "primes.json")) as fp:
primes = np.array(json.load(fp))
if max_N:
return primes[primes <= max_N]
return primes
class SpiralScene(MovingCameraScene):
CONFIG = {
"axes_config": {
"number_line_config": {
"stroke_width": 1.5,
}
},
"default_dot_color": TEAL,
"p_spiral_width": 6,
}
def setup(self):
super().setup()
self.axes = Axes(**self.axes_config)
self.add(self.axes)
def get_v_spiral(self, sequence, axes=None, data_point_width=None):
if axes is None:
axes = self.axes
if data_point_width is None:
unit = get_norm(axes.c2p(1, 0) - axes.c2p(0, 0)),
data_point_width = max(
0.2 / (-np.log10(unit) + 1),
0.02,
)
return VGroup(*[
Square(
side_length=data_point_width,
fill_color=self.default_dot_color,
fill_opacity=1,
stroke_width=0,
).move_to(self.get_polar_point(n, n, axes))
for n in sequence
])
def get_p_spiral(self, sequence, axes=None):
if axes is None:
axes = self.axes
result = PMobject(
color=self.default_dot_color,
stroke_width=self.p_spiral_width,
)
result.add_points([
self.get_polar_point(n, n, axes)
for n in sequence
])
return result
def get_prime_v_spiral(self, max_N, **kwargs):
primes = read_in_primes(max_N)
return self.get_v_spiral(primes, **kwargs)
def get_prime_p_spiral(self, max_N, **kwargs):
primes = read_in_primes(max_N)
return self.get_p_spiral(primes, **kwargs)
def get_polar_point(self, r, theta, axes=None):
if axes is None:
axes = self.axes
return axes.c2p(r * np.cos(theta), r * np.sin(theta))
def set_scale(self, scale,
axes=None,
spiral=None,
to_shrink=None,
min_data_point_width=0.05,
target_p_spiral_width=None,
run_time=3):
if axes is None:
axes = self.axes
sf = self.get_scale_factor(scale, axes)
anims = []
for mob in [axes, spiral, to_shrink]:
if mob is None:
continue
mob.generate_target()
mob.target.scale(sf, about_point=ORIGIN)
if mob is spiral:
if isinstance(mob, VMobject):
old_width = mob[0].get_width()
for submob in mob.target:
submob.set_width(max(
old_width * sf,
min_data_point_width,
))
elif isinstance(mob, PMobject):
if target_p_spiral_width is not None:
mob.target.set_stroke_width(target_p_spiral_width)
anims.append(MoveToTarget(mob))
if run_time == 0:
for anim in anims:
anim.begin()
anim.update(1)
anim.finish()
else:
self.play(
*anims,
run_time=run_time,
rate_func=lambda t: interpolate(
smooth(t),
smooth(t)**(sf**(0.5)),
t,
)
)
def get_scale_factor(self, target_scale, axes=None):
if axes is None:
axes = self.axes
unit = get_norm(axes.c2p(1, 0) - axes.c2p(0, 0))
return 1 / (target_scale * unit)
# Scenes
class RefresherOnPolarCoordinates(MovingCameraScene):
CONFIG = {
"x_color": GREEN,
"y_color": RED,
"r_color": YELLOW,
"theta_color": LIGHT_PINK,
}
def construct(self):
self.show_xy_coordinates()
self.transition_to_polar_grid()
self.show_polar_coordinates()
self.show_all_nn_tuples()
def show_xy_coordinates(self):
plane = NumberPlane()
plane.add_coordinates()
x = 3 * np.cos(PI / 6)
y = 3 * np.sin(PI / 6)
point = plane.c2p(x, y)
xp = plane.c2p(x, 0)
origin = plane.c2p(0, 0)
x_color = self.x_color
y_color = self.y_color
x_line = Line(origin, xp, color=x_color)
y_line = Line(xp, point, color=y_color)
dot = Dot(point)
coord_label = self.get_coord_label(0, 0, x_color, y_color)
x_coord = coord_label.x_coord
y_coord = coord_label.y_coord
coord_label.next_to(dot, UR, SMALL_BUFF)
x_brace = Brace(x_coord, UP)
y_brace = Brace(y_coord, UP)
x_brace.add(x_brace.get_tex("x").set_color(x_color))
y_brace.add(y_brace.get_tex("y").set_color(y_color))
x_brace.add_updater(lambda m: m.next_to(x_coord, UP, SMALL_BUFF))
y_brace.add_updater(lambda m: m.next_to(y_coord, UP, SMALL_BUFF))
self.add(plane)
self.add(dot, coord_label)
self.add(x_brace, y_brace)
coord_label.add_updater(
lambda m: m.next_to(dot, UR, SMALL_BUFF)
)
self.play(
ShowCreation(x_line),
ChangeDecimalToValue(x_coord, x),
UpdateFromFunc(
dot,
lambda d: d.move_to(x_line.get_end()),
),
run_time=2,
)
self.play(
ShowCreation(y_line),
ChangeDecimalToValue(y_coord, y),
UpdateFromFunc(
dot,
lambda d: d.move_to(y_line.get_end()),
),
run_time=2,
)
self.wait()
self.xy_coord_mobjects = VGroup(
x_line, y_line, coord_label,
x_brace, y_brace,
)
self.plane = plane
self.dot = dot
def transition_to_polar_grid(self):
self.polar_grid = self.get_polar_grid()
self.add(self.polar_grid, self.dot)
self.play(
FadeOut(self.xy_coord_mobjects),
FadeOut(self.plane),
ShowCreation(self.polar_grid, run_time=2),
)
self.wait()
def show_polar_coordinates(self):
dot = self.dot
plane = self.plane
origin = plane.c2p(0, 0)
r_color = self.r_color
theta_color = self.theta_color
r_line = Line(origin, dot.get_center())
r_line.set_color(r_color)
r_value = r_line.get_length()
theta_value = r_line.get_angle()
coord_label = self.get_coord_label(r_value, theta_value, r_color, theta_color)
r_coord = coord_label.x_coord
theta_coord = coord_label.y_coord
coord_label.add_updater(lambda m: m.next_to(dot, UP, buff=SMALL_BUFF))
r_coord.add_updater(lambda d: d.set_value(
get_norm(dot.get_center())
))
theta_coord.add_background_rectangle()
theta_coord.add_updater(lambda d: d.set_value(
(angle_of_vector(dot.get_center()) % TAU)
))
coord_label[-1].add_updater(
lambda m: m.next_to(theta_coord, RIGHT, SMALL_BUFF)
)
non_coord_parts = VGroup(*[
part
for part in coord_label
if part not in [r_coord, theta_coord]
])
r_label = TexMobject("r")
r_label.set_color(r_color)
r_label.add_updater(lambda m: m.next_to(r_coord, UP))
theta_label = TexMobject("\\theta")
theta_label.set_color(theta_color)
theta_label.add_updater(lambda m: m.next_to(theta_coord, UP))
r_coord_copy = r_coord.copy()
r_coord_copy.add_updater(
lambda m: m.next_to(r_line.get_center(), UL, buff=0)
)
degree_label = DecimalNumber(0, num_decimal_places=1, unit="^\\circ")
arc = Arc(radius=1, angle=theta_value)
arc.set_color(theta_color)
degree_label.set_color(theta_color)
# Show r
self.play(
ShowCreation(r_line, run_time=2),
ChangeDecimalToValue(r_coord_copy, r_value, run_time=2),
VFadeIn(r_coord_copy, run_time=0.5),
)
r_coord.set_value(r_value)
self.add(non_coord_parts, r_coord_copy)
self.play(
FadeIn(non_coord_parts),
ReplacementTransform(r_coord_copy, r_coord),
FadeInFromDown(r_label),
)
self.wait()
# Show theta
degree_label.next_to(arc.get_start(), UR, SMALL_BUFF)
line = r_line.copy()
line.rotate(-theta_value, about_point=ORIGIN)
line.set_color(theta_color)
self.play(
ShowCreation(arc),
Rotate(line, theta_value, about_point=ORIGIN),
VFadeInThenOut(line),
ChangeDecimalToValue(degree_label, theta_value / DEGREES),
)
self.play(
degree_label.scale, 0.9,
degree_label.move_to, theta_coord,
FadeInFromDown(theta_label),
)
self.wait()
degree_cross = Cross(degree_label)
radians_word = TextMobject("in radians")
radians_word.scale(0.9)
radians_word.set_color(theta_color)
radians_word.add_background_rectangle()
radians_word.add_updater(
lambda m: m.next_to(theta_label, RIGHT, aligned_edge=DOWN)
)
self.play(ShowCreation(degree_cross))
self.play(
FadeOutAndShift(
VGroup(degree_label, degree_cross),
DOWN
),
FadeIn(theta_coord)
)
self.play(FadeIn(radians_word))
self.wait()
# Move point around
r_line.add_updater(
lambda l: l.put_start_and_end_on(ORIGIN, dot.get_center())
)
arc.add_updater(
lambda m: m.become(Arc(
angle=(r_line.get_angle() % TAU),
color=theta_color,
radius=1,
))
)
self.add(coord_label)
for angle in [PI - theta_value, PI - 0.001, -TAU + 0.002]:
self.play(
Rotate(dot, angle, about_point=ORIGIN),
run_time=3,
)
self.wait()
self.play(
FadeOut(coord_label),
FadeOut(r_line),
FadeOut(arc),
FadeOut(r_label),
FadeOut(theta_label),
FadeOut(radians_word),
FadeOut(dot),
)
def show_all_nn_tuples(self):
self.remove(self.dot)
primes = generate_prime_list(20)
non_primes = list(range(1, 20))
for prime in primes:
non_primes.remove(prime)
pp_points = VGroup(*map(self.get_nn_point, primes))
pp_points[0][1].shift(0.3 * LEFT + SMALL_BUFF * UP)
np_points = VGroup(*map(self.get_nn_point, non_primes))
pp_points.set_color(TEAL)
np_points.set_color(WHITE)
pp_points.set_stroke(BLACK, 4, background=True)
np_points.set_stroke(BLACK, 4, background=True)
frame = self.camera_frame
self.play(
ApplyMethod(frame.scale, 2),
LaggedStartMap(
FadeInFromDown, pp_points
),
run_time=2
)
self.wait()
self.play(LaggedStartMap(FadeIn, np_points))
self.play(frame.scale, 0.5)
self.wait()
# Talk about 1
one = np_points[0]
r_line = Line(ORIGIN, one.dot.get_center())
r_line.set_color(self.r_color)
# pre_arc = Line(RIGHT, UR, color=self.r_color)
theta_tracker = ValueTracker(1)
arc = always_redraw(lambda: self.get_arc(theta_tracker.get_value()))
one_rect = SurroundingRectangle(one)
one_r_rect = SurroundingRectangle(one.label[1])
one_theta_rect = SurroundingRectangle(one.label[3])
one_theta_rect.set_color(self.theta_color)
self.play(ShowCreation(one_rect))
self.add(r_line, np_points, pp_points, one_rect)
self.play(
ReplacementTransform(one_rect, one_r_rect),
ShowCreation(r_line)
)
self.wait()
# self.play(TransformFromCopy(r_line, pre_arc))
# self.add(pre_arc, one)
self.play(
TransformFromCopy(r_line, arc),
ReplacementTransform(one_r_rect, one_theta_rect)
)
self.add(arc, one, one_theta_rect)
self.play(FadeOut(one_theta_rect))
self.wait()
# Talk about 2
self.play(theta_tracker.set_value, 2)
self.wait()
self.play(Rotate(r_line, angle=1, about_point=ORIGIN))
self.play(r_line.scale, 2, {'about_point': ORIGIN})
self.wait()
# And now 3
self.play(
theta_tracker.set_value, 3,
Rotate(r_line, angle=1, about_point=ORIGIN),
)
self.wait()
self.play(
r_line.scale, 3 / 2, {"about_point": ORIGIN}
)
self.wait()
# Finally 4
self.play(
theta_tracker.set_value, 4,
Rotate(r_line, angle=1, about_point=ORIGIN),
)
self.wait()
self.play(
r_line.scale, 4 / 3, {"about_point": ORIGIN}
)
self.wait()
# Zoom out and show spiral
spiral = ParametricFunction(
lambda t: self.get_polar_point(t, t),
t_min=0,
t_max=25,
stroke_width=1.5,
)
self.add(spiral, pp_points, np_points)
self.polar_grid.generate_target()
for mob in self.polar_grid:
if not isinstance(mob[0], Integer):
mob.set_stroke(width=1)
self.play(
ApplyMethod(
frame.scale, 3,
run_time=5,
rate_func=lambda t: smooth(t, 2)
),
ShowCreation(
spiral,
run_time=6,
),
FadeOut(r_line),
FadeOut(arc),
MoveToTarget(self.polar_grid)
)
self.wait()
#
def get_nn_point(self, n):
point = self.get_polar_point(n, n)
dot = Dot(point)
coord_label = self.get_coord_label(
n, n,
include_background_rectangle=False,
num_decimal_places=0
)
coord_label.next_to(dot, UR, buff=0)
result = VGroup(dot, coord_label)
result.dot = dot
result.label = coord_label
return result
def get_polar_grid(self, radius=25):
plane = self.plane
axes = VGroup(
Line(radius * DOWN, radius * UP),
Line(radius * LEFT, radius * RIGHT),
)
axes.set_stroke(width=2)
circles = VGroup(*[
Circle(color=BLUE, stroke_width=1, radius=r)
for r in range(1, int(radius))
])
rays = VGroup(*[
Line(
ORIGIN, radius * RIGHT,
color=BLUE,
stroke_width=1,
).rotate(angle, about_point=ORIGIN)
for angle in np.arange(0, TAU, TAU / 16)
])
labels = VGroup(*[
Integer(n).scale(0.5).next_to(
plane.c2p(n, 0), DR, SMALL_BUFF
)
for n in range(1, int(radius))
])
return VGroup(
circles, rays, labels, axes,
)
def get_coord_label(self,
x=0,
y=0,
x_color=WHITE,
y_color=WHITE,
include_background_rectangle=True,
**decimal_kwargs):
x_coord = DecimalNumber(x, **decimal_kwargs)
x_coord.set_color(x_color)
y_coord = DecimalNumber(y, **decimal_kwargs)
y_coord.set_color(y_color)
coord_label = VGroup(
TexMobject("("), x_coord,
TexMobject(","), y_coord,
TexMobject(")")
)
coord_label.arrange(RIGHT, buff=SMALL_BUFF)
coord_label[2].align_to(coord_label[0], DOWN)
coord_label.x_coord = x_coord
coord_label.y_coord = y_coord
if include_background_rectangle:
coord_label.add_background_rectangle()
return coord_label
def get_polar_point(self, r, theta):
plane = self.plane
return plane.c2p(r * np.cos(theta), r * np.sin(theta))
def get_arc(self, theta, r=1, color=None):
if color is None:
color = self.theta_color
return Arc(
angle=theta,
radius=r,
stroke_color=color,
)
class IntroducePrimePatterns(SpiralScene):
CONFIG = {
"small_n_primes": 25000,
"big_n_primes": 1000000,
"axes_config": {
"x_min": -25,
"x_max": 25,
"y_min": -25,
"y_max": 25,
},
"spiral_scale": 3e3,
"ray_scale": 1e5,
}
def construct(self):
self.slowly_zoom_out()
self.show_clumps_of_four()
def slowly_zoom_out(self):
zoom_time = 8
prime_spiral = self.get_prime_p_spiral(self.small_n_primes)
prime_spiral.set_stroke_width(25)
self.add(prime_spiral)
self.set_scale(3, spiral=prime_spiral)
self.wait()
self.set_scale(
self.spiral_scale,
spiral=prime_spiral,
target_p_spiral_width=8,
run_time=zoom_time,
)
self.wait()
self.remove(prime_spiral)
prime_spiral = self.get_prime_p_spiral(self.big_n_primes)
prime_spiral.set_stroke_width(8)
self.set_scale(
self.ray_scale,
spiral=prime_spiral,
target_p_spiral_width=4,
run_time=zoom_time,
)
self.wait()
def show_clumps_of_four(self):
line_groups = VGroup()
for n in range(71):
group = VGroup()
for k in [-3, -1, 1, 3]:
r = ((10 * n + k) * INV_113_MOD_710) % 710
group.add(self.get_arithmetic_sequence_line(
710, r, self.big_n_primes
))
line_groups.add(group)
line_groups.set_stroke(YELLOW, 2, opacity=0.5)
self.play(ShowCreation(line_groups[0]))
for g1, g2 in zip(line_groups, line_groups[1:5]):
self.play(
FadeOut(g1),
ShowCreation(g2)
)
self.play(
FadeOut(line_groups[4]),
LaggedStartMap(
VFadeInThenOut,
line_groups[4:],
lag_ratio=0.5,
run_time=5,
)
)
self.wait()
def get_arithmetic_sequence_line(self, N, r, max_val, skip_factor=5):
line = VMobject()
line.set_points_smoothly([
self.get_polar_point(x, x)
for x in range(r, max_val, skip_factor * N)
])
return line
class AskWhat(TeacherStudentsScene):
def construct(self):
screen = self.screen
self.student_says(
"I'm sory,\\\\what?!?",
target_mode="angry",
look_at_arg=screen,
student_index=2,
added_anims=[
self.teacher.change, "happy", screen,
self.students[0].change, "confused", screen,
self.students[1].change, "confused", screen,
]
)
self.wait(3)
class CountSpirals(IntroducePrimePatterns):
CONFIG = {
"count_sound": "pen_click.wav",
}
def construct(self):
prime_spiral = self.get_prime_p_spiral(self.small_n_primes)
self.add(prime_spiral)
self.set_scale(
self.spiral_scale,
spiral=prime_spiral,
run_time=0,
)
spiral_lines = self.get_all_primative_arithmetic_lines(
44, self.small_n_primes, INV_7_MOD_44,
)
spiral_lines.set_stroke(YELLOW, 2, opacity=0.5)
counts = VGroup()
for n, spiral in zip(it.count(1), spiral_lines):
count = Integer(n)
count.move_to(spiral.point_from_proportion(0.25))
counts.add(count)
run_time = 3
self.play(
ShowIncreasingSubsets(spiral_lines),
ShowSubmobjectsOneByOne(counts),
run_time=run_time,
rate_func=linear,
)
self.add_count_clicks(len(spiral_lines), run_time)
self.play(
counts[-1].scale, 3,
counts[-1].set_stroke, BLACK, 5, {"background": True},
)
self.wait()
def get_all_primative_arithmetic_lines(self, N, max_val, mult_factor):
lines = VGroup()
for r in range(1, N):
if get_gcd(N, r) == 1:
lines.add(
self.get_arithmetic_sequence_line(N, (mult_factor * r) % N, max_val)
)
return lines
def add_count_clicks(self, N, time, rate_func=linear):
alphas = np.arange(0, 1, 1 / N)
if rate_func is linear:
delays = time * alphas
else:
delays = time * np.array([
binary_search(
rate_func,
alpha,
0,
1,
)
for alpha in alphas
])
for delay in delays:
self.add_sound(
self.count_sound,
time_offset=-delay,
gain=-15,
)
class CountRays(CountSpirals):
def construct(self):
prime_spiral = self.get_prime_p_spiral(self.big_n_primes)
self.add(prime_spiral)
self.set_scale(
self.ray_scale,
spiral=prime_spiral,
run_time=0,
)
spiral_lines = self.get_all_primative_arithmetic_lines(
710, self.big_n_primes, INV_113_MOD_710,
)
spiral_lines.set_stroke(YELLOW, 2, opacity=0.5)
counts = VGroup()
for n, spiral in zip(it.count(1), spiral_lines):
count = Integer(n)
count.move_to(spiral.point_from_proportion(0.25))
counts.add(count)
run_time = 6
self.play(
ShowIncreasingSubsets(spiral_lines),
ShowSubmobjectsOneByOne(counts),
run_time=run_time,
rate_func=smooth,
)
self.add_count_clicks(len(spiral_lines), run_time, rate_func=smooth)
self.play(
counts[-1].scale, 3,
counts[-1].set_stroke, BLACK, 5, {"background": True},
)
self.wait()
self.play(FadeOut(spiral_lines))
self.wait()
class AskAboutRelationToPrimes(TeacherStudentsScene):
def construct(self):
numbers = TextMobject("20, 280")
arrow = Arrow(LEFT, RIGHT)
primes = TextMobject("2, 3, 5, 7, 11, \\dots")
q_marks = TextMobject("???")
q_marks.set_color(YELLOW)
group = VGroup(numbers, arrow, primes)
group.arrange(RIGHT)
q_marks.next_to(arrow, UP)
group.add(q_marks)
group.scale(1.5)
group.next_to(self.pi_creatures, UP, LARGE_BUFF)
self.play(
self.get_student_changes(
*3 * ["maybe"],
look_at_arg=numbers,
),
self.teacher.change, "maybe", numbers,
ShowCreation(arrow),
FadeInFrom(numbers, RIGHT)
)
self.play(
FadeInFrom(primes, LEFT),
)
self.play(
LaggedStartMap(FadeInFromDown, q_marks[0]),
Blink(self.teacher)
)
self.wait(3)
class ZoomOutOnPrimesWithNumbers(IntroducePrimePatterns):
def construct(self):
pass