Beginning Sierpinski graph in hanoi.py

This commit is contained in:
Grant Sanderson 2016-11-21 14:40:16 -08:00
parent cc9aace93f
commit 9a5b3a6de3

721
hanoi.py
View file

@ -70,6 +70,7 @@ class CountingScene(Scene):
)
for point in self.get_template_configuration()
])
dots[-1].set_stroke(width = 0)
dots.scale_to_fit_height(self.dot_configuration_height)
return dots
@ -109,15 +110,11 @@ class CountingScene(Scene):
moving_dot.set_fill(opacity = 0)
continue_rolling_over = True
first_move = True
place = 0
while continue_rolling_over:
if first_move:
added_anims = list(
self.get_digit_increment_animations()+\
added_anims
)
first_move = False
self.number += 1
added_anims = list(added_anims) #Silly python objects...
added_anims += self.get_new_configuration_animations()
while continue_rolling_over:
moving_dot.target.replace(
self.dot_template_iterators[place].next()
)
@ -163,16 +160,21 @@ class CountingScene(Scene):
moving_dot[0].set_fill(opacity = 0)
else:
continue_rolling_over = False
self.play(*self.get_digit_increment_animations())
def get_new_configuration_animations(self):
if self.is_perfect_power():
self.add_configuration()
return [FadeIn(self.dot_templates[-1])]
else:
return []
def get_digit_increment_animations(self):
result = []
self.number += 1
new_number_mob = self.get_number_mob(self.number)
new_number_mob.move_to(self.number_mob, RIGHT)
if self.is_perfect_power():
self.add_configuration()
place = len(new_number_mob.split())-1
result.append(FadeIn(self.dot_templates[place]))
arrow = Arrow(
new_number_mob[place].get_top(),
self.dot_templates[place].get_bottom(),
@ -258,6 +260,8 @@ class TowersOfHanoiScene(Scene):
"num_disks" : 5,
"peg_width" : 0.25,
"peg_height" : 2.5,
"peg_spacing" : 4,
"include_peg_labels" : True,
"middle_peg_bottom" : 0.5*DOWN,
"disk_height" : 0.4,
"disk_min_width" : 1,
@ -280,13 +284,15 @@ class TowersOfHanoiScene(Scene):
peg.move_to(self.middle_peg_bottom, DOWN)
self.pegs = VGroup(*[
peg.copy().shift(vect)
for vect in 4*LEFT, ORIGIN, 4*RIGHT
for vect in self.peg_spacing*LEFT, ORIGIN, self.peg_spacing*RIGHT
])
self.peg_labels = VGroup(*[
TexMobject(char).next_to(peg, DOWN)
for char, peg in zip("ABC", self.pegs)
])
self.add(self.pegs, self.peg_labels)
self.add(self.pegs)
if self.include_peg_labels:
self.peg_labels = VGroup(*[
TexMobject(char).next_to(peg, DOWN)
for char, peg in zip("ABC", self.pegs)
])
self.add(self.peg_labels)
def add_disks(self):
self.disks = VGroup(*[
@ -366,6 +372,19 @@ class TowersOfHanoiScene(Scene):
return index
raise Exception("Tower's of Honoi rule broken: No available disks")
def set_disk_config(self, peg_indices):
assert(len(peg_indices) == self.num_disks)
self.disk_tracker = [set([]) for x in range(3)]
for n, peg_index in enumerate(peg_indices):
disk_index = self.num_disks - n - 1
disk = self.disks[disk_index]
peg = self.pegs[peg_index]
disk.move_to(peg.get_bottom(), DOWN)
n_disks_here = len(self.disk_tracker[peg_index])
disk.shift(disk.get_height()*n_disks_here*UP)
self.disk_tracker[peg_index].add(disk_index)
def move_disk(self, disk_index, **kwargs):
next_peg_index = self.get_available_peg(disk_index)
self.move_disk_to_peg(disk_index, next_peg_index, **kwargs)
@ -492,7 +511,6 @@ def get_base_b_tex_mob(number, base, n_digits):
number = (number - remainder)/base
return result.center()
def get_binary_tex_mob(number, n_bits = 4):
return get_base_b_tex_mob(number, 2, n_bits)
@ -1197,8 +1215,8 @@ class IntroduceSolveByCounting(TowersOfHanoiScene):
for disk in self.disks:
disk.original_fill_color = disk.get_color()
braces = [
Brace(VGroup(*self.curr_bit_mob[-n:]))
for n in range(1, self.num_disks + 1)
Brace(VGroup(*self.curr_bit_mob[:n]))
for n in range(1, self.num_disks+1)
]
word_list = [
brace.get_text(text)
@ -1219,7 +1237,7 @@ class IntroduceSolveByCounting(TowersOfHanoiScene):
Write(words, run_time = 1)
)
disk = self.disks[0]
last_bit = self.curr_bit_mob[-1]
last_bit = self.curr_bit_mob[0]
last_bit.save_state()
self.play(
disk.set_fill, YELLOW,
@ -1241,7 +1259,7 @@ class IntroduceSolveByCounting(TowersOfHanoiScene):
Transform(brace, braces[1]),
)
disk = self.disks[1]
twos_bit = self.curr_bit_mob[-2]
twos_bit = self.curr_bit_mob[1]
twos_bit.save_state()
self.play(
disk.set_fill, MAROON_B,
@ -1281,7 +1299,7 @@ class IntroduceSolveByCounting(TowersOfHanoiScene):
)
self.play(self.get_increment_animation())
disk = self.disks[2]
fours_bit = self.curr_bit_mob[-3]
fours_bit = self.curr_bit_mob[2]
fours_bit.save_state()
self.play(
disk.set_fill, RED,
@ -1298,10 +1316,8 @@ class IntroduceSolveByCounting(TowersOfHanoiScene):
)
self.dither()
for disk_index in 0, 1, 0:
self.move_disk(
disk_index,
added_anims = [self.get_increment_animation()]
)
self.play(self.get_increment_animation())
self.move_disk(disk_index)
self.dither()
##Eighth incremement
@ -1313,7 +1329,7 @@ class IntroduceSolveByCounting(TowersOfHanoiScene):
Write(words, run_time = 1)
)
disk = self.disks[3]
eights_bit = self.curr_bit_mob[0]
eights_bit = self.curr_bit_mob[3]
eights_bit.save_state()
self.play(
disk.set_fill, GREEN,
@ -1328,11 +1344,8 @@ class IntroduceSolveByCounting(TowersOfHanoiScene):
)
self.play(*map(FadeOut, [brace, words]))
for disk_index in get_ruler_sequence(2):
self.move_disk(
disk_index,
stay_on_peg = False,
added_anims = [self.get_increment_animation()]
)
self.play(self.get_increment_animation())
self.move_disk(disk_index, stay_on_peg = False)
self.dither()
def initialize_bit_mobs(self):
@ -1341,18 +1354,24 @@ class IntroduceSolveByCounting(TowersOfHanoiScene):
for n in range(2**(self.num_disks))
])
bit_mobs.scale(2)
self.bit_mobs_iter = it.cycle(bit_mobs)
self.curr_bit_mob = self.bit_mobs_iter.next()
for bit_mob in bit_mobs:
bit_mob.align_data(self.curr_bit_mob)
for bit, disk in zip(bit_mob, reversed(list(self.disks))):
bit.highlight(disk.get_color())
bit_mobs.next_to(self.peg_labels, DOWN)
self.bit_mobs_iter = it.cycle(bit_mobs)
self.curr_bit_mob = self.bit_mobs_iter.next()
self.add(self.curr_bit_mob)
def get_increment_animation(self):
return Succession(
Transform(self.curr_bit_mob, self.bit_mobs_iter.next()),
Transform(
self.curr_bit_mob, self.bit_mobs_iter.next(),
submobject_mode = "lagged_start",
path_arc = -np.pi/3
),
Animation(self.curr_bit_mob)
)
@ -1360,16 +1379,19 @@ class SolveSixDisksByCounting(IntroduceSolveByCounting):
CONFIG = {
"num_disks" : 6,
"stay_on_peg" : False,
"run_time_per_move" : 1,
"run_time_per_move" : 0.5,
}
def construct(self):
self.initialize_bit_mobs()
for disk_index in get_ruler_sequence(self.num_disks-1):
self.play(
self.get_increment_animation(),
run_time = self.run_time_per_move,
)
self.move_disk(
disk_index,
stay_on_peg = self.stay_on_peg,
run_time = self.run_time_per_move,
added_anims = [self.get_increment_animation()],
)
self.dither()
@ -1747,48 +1769,74 @@ class SolveTwoDisksByCounting(SolveSixDisksByCounting):
def construct(self):
self.initialize_bit_mobs()
for disk_index in 0, 1, 0:
self.play(self.get_increment_animation())
self.move_disk(
disk_index,
stay_on_peg = False,
added_anims = [self.get_increment_animation()]
)
self.dither()
class ShowFourDiskFourBitsParallel(IntroduceSolveByCounting):
CONFIG = {
"num_disks" : 4,
"small_run_time" : 0.2,
"subtask_run_time" : 1,
}
def construct(self):
self.initialize_bit_mobs()
self.subtask()
self.counting_subtask()
self.dither()
self.disk_subtask()
self.dither()
self.play(self.get_increment_animation())
self.move_disk(
self.num_disks-1,
stay_on_peg = False,
added_anims = [
self.get_increment_animation()
]
)
self.dither()
self.subtask()
self.counting_subtask()
self.dither()
self.disk_subtask()
self.dither()
def subtask(self):
def disk_subtask(self):
sequence = get_ruler_sequence(self.num_disks-2)
run_time = float(self.subtask_run_time)/len(sequence)
for disk_index in get_ruler_sequence(self.num_disks-2):
self.move_disk(
disk_index,
run_time = self.small_run_time,
run_time = run_time,
stay_on_peg = False,
added_anims = [
self.get_increment_animation()
]
)
# curr_peg = self.disk_index_to_peg_index(0)
# self.move_subtower_to_peg(self.num_disks-1, curr_peg+1)
def counting_subtask(self):
num_tasks = 2**(self.num_disks-1)-1
run_time = float(self.subtask_run_time)/num_tasks
# for x in range(num_tasks):
# self.play(
# self.get_increment_animation(),
# run_time = run_time
# )
self.play(
Succession(*[
self.get_increment_animation()
for x in range(num_tasks)
]),
rate_func = None,
run_time = self.subtask_run_time
)
def get_increment_animation(self):
return Transform(
self.curr_bit_mob, self.bit_mobs_iter.next(),
path_arc = -np.pi/3,
)
class ShowSixDiskSixBitsParallel(ShowFourDiskFourBitsParallel):
CONFIG = {
"num_disks" : 6,
"small_run_time" : 0.05
"subtask_run_time" : 2
}
class CoolRight(Scene):
@ -2238,10 +2286,14 @@ class CompareNumberSystems(Scene):
mob.brace = Brace(mob)
mob.name = mob.brace.get_text(text)
zero_one_two.name.gradient_highlight(BLUE, GREEN)
dots = TexMobject("\\dots")
dots.next_to(zero_one.name, RIGHT, aligned_edge = DOWN, buff = SMALL_BUFF)
keith = Keith()
keith.shift(2*DOWN+3*LEFT)
keith.look_at(zero_one_two)
morty = Mortimer()
morty.shift(2*DOWN+3*RIGHT)
for title, symbol in zip(titles, symbols):
self.play(FadeIn(title))
@ -2264,10 +2316,31 @@ class CompareNumberSystems(Scene):
)
self.play(keith.change_mode, "sassy")
self.play(Blink(keith))
self.play(FadeIn(morty))
self.play(
morty.change_mode, "sassy",
morty.look_at, zero_one_two
)
self.play(Blink(morty))
self.dither()
self.play(
morty.shrug,
morty.look_at, keith.eyes,
keith.shrug,
keith.look_at, morty.eyes
)
self.dither()
self.play(
morty.change_mode, "hesitant",
morty.look_at, zero_one.name,
keith.change_mode, "erm",
keith.look_at, zero_one.name
)
self.play(Blink(morty))
self.play(Write(dots, run_time = 3))
self.dither()
class CountInTernary(CountingScene):
class IntroduceTernaryCounting(CountingScene):
CONFIG = {
"base" : 3,
"counting_dot_starting_position" : (SPACE_WIDTH-1)*RIGHT + (SPACE_HEIGHT-1)*UP,
@ -2278,13 +2351,547 @@ class CountInTernary(CountingScene):
"num_start_location" : DOWN+RIGHT,
}
def construct(self):
for x in range(27):
for x in range(2):
self.increment()
self.dither()
self.increment()
brace = Brace(self.number_mob[-1])
threes_place = brace.get_text("Three's place")
self.play(
GrowFromCenter(brace),
Write(threes_place)
)
self.dither()
for x in range(6):
self.increment()
self.dither()
new_brace = Brace(self.number_mob[-1])
nines_place = new_brace.get_text("Nine's place")
self.play(
Transform(brace, new_brace),
Transform(threes_place, nines_place),
)
self.dither()
for x in range(9):
self.increment()
class TernaryCountingSelfSimilarPattern(Scene):
CONFIG = {
"num_trits" : 3,
"colors" : CountingScene.CONFIG["power_colors"][:3],
}
def construct(self):
colors = self.colors
title = TextMobject("Count to " + "2"*self.num_trits)
for i, color in enumerate(colors):
title[-i-1].highlight(color)
steps = VGroup(*map(TextMobject, [
"Count to %s,"%("2"*(self.num_trits-1)),
"Roll over,",
"Count to %s,"%("2"*(self.num_trits-1)),
"Roll over,",
"Count to %s,"%("2"*(self.num_trits-1)),
]))
steps.arrange_submobjects(RIGHT)
for step in steps[::2]:
for i, color in enumerate(colors[:-1]):
step[-i-2].highlight(color)
VGroup(*steps[1::2]).highlight(colors[-1])
steps.scale_to_fit_width(2*SPACE_WIDTH-1)
brace = Brace(steps, UP)
word_group = VGroup(title, brace, steps)
word_group.arrange_submobjects(DOWN)
word_group.to_edge(UP)
ternary_mobs = VGroup(*[
get_ternary_tex_mob(n, n_trits = self.num_trits)
for n in range(3**self.num_trits)
])
ternary_mobs.scale(2)
ternary_mob_iter = it.cycle(ternary_mobs)
curr_ternary_mob = ternary_mob_iter.next()
for trits in ternary_mobs:
trits.align_data(curr_ternary_mob)
for trit, color in zip(trits, colors):
trit.highlight(color)
def get_increment():
return Transform(
curr_ternary_mob, ternary_mob_iter.next(),
submobject_mode = "lagged_start",
path_arc = -np.pi/3
)
self.add(curr_ternary_mob, title)
self.play(GrowFromCenter(brace))
for i, step in enumerate(steps):
self.play(Write(step, run_time = 1))
if i%2 == 0:
self.play(
Succession(*[
get_increment()
for x in range(3**(self.num_trits-1)-1)
]),
run_time = 1
)
else:
self.play(get_increment())
self.dither()
class TernaryCountingSelfSimilarPatternFiveTrits(TernaryCountingSelfSimilarPattern):
CONFIG = {
"num_trits" : 5,
"colors" : color_gradient([YELLOW, PINK, RED], 5),
}
class CountInTernary(IntroduceTernaryCounting):
def construct(self):
for x in range(9):
self.increment()
self.dither()
class SolveConstrainedWithTernaryCounting(ConstrainedTowersOfHanoiScene):
CONFIG = {
"num_disks" : 4,
}
def construct(self):
for x in range(3**self.num_disks-1):
self.increment(run_time = 0.75)
self.dither()
def setup(self):
ConstrainedTowersOfHanoiScene.setup(self)
ternary_mobs = VGroup(*[
get_ternary_tex_mob(x)
for x in range(3**self.num_disks)
])
ternary_mobs.scale(2)
ternary_mobs.next_to(self.peg_labels, DOWN)
for trits in ternary_mobs:
trits.align_data(ternary_mobs[0])
trits.gradient_highlight(*self.disk_start_and_end_colors)
self.ternary_mob_iter = it.cycle(ternary_mobs)
self.curr_ternary_mob = self.ternary_mob_iter.next().copy()
self.disk_index_iter = it.cycle(
get_ternary_ruler_sequence(self.num_disks-1)
)
self.ternary_mobs = ternary_mobs
def increment(self, run_time = 1, stay_on_peg = False):
self.increment_number(run_time)
self.move_next_disk(run_time, stay_on_peg)
def increment_number(self, run_time = 1):
self.play(Transform(
self.curr_ternary_mob, self.ternary_mob_iter.next(),
path_arc = -np.pi/3,
submobject_mode = "lagged_start",
run_time = run_time,
))
def move_next_disk(self, run_time = None, stay_on_peg = False):
self.move_disk(
self.disk_index_iter.next(),
run_time = run_time,
stay_on_peg = stay_on_peg
)
class DescribeSolutionByCountingToConstrained(SolveConstrainedWithTernaryCounting):
def construct(self):
braces = [
Brace(VGroup(*self.curr_ternary_mob[:n+1]))
for n in range(self.num_disks)
]
words = [
brace.get_text(text)
for brace, text in zip(braces, [
"Only flip last trit",
"Roll over once",
"Roll over twice",
"Roll over three times",
])
]
#Count 1, 2
color = YELLOW
brace = braces[0]
word = words[0]
words[0].highlight(color)
self.increment_number()
self.play(
FadeIn(brace),
Write(word, run_time = 1),
self.curr_ternary_mob[0].highlight, color
)
self.dither()
self.play(
self.disks[0].set_fill, color,
self.disks[0].label.set_fill, BLACK,
)
self.move_next_disk(stay_on_peg = True)
self.dither()
self.ternary_mobs[2][0].highlight(color)
self.increment_number()
self.move_next_disk(stay_on_peg = True)
self.dither()
#Count 10
color = MAROON_B
words[1].highlight(color)
self.increment_number()
self.play(
Transform(brace, braces[1]),
Transform(word, words[1]),
self.curr_ternary_mob[1].highlight, color
)
self.dither()
self.play(
self.disks[1].set_fill, color,
self.disks[1].label.set_fill, BLACK,
)
self.move_next_disk(stay_on_peg = True)
self.dither()
self.play(*map(FadeOut, [brace, word]))
#Count up to 22
for x in range(5):
self.increment()
self.dither()
#Count to 100
color = RED
words[2].highlight(color)
self.dither()
self.increment_number()
self.play(
FadeIn(braces[2]),
Write(words[2], run_time = 1),
self.curr_ternary_mob[2].set_fill, color,
self.disks[2].set_fill, color,
self.disks[2].label.set_fill, BLACK,
)
self.dither()
self.move_next_disk(stay_on_peg = True)
self.dither()
self.play(*map(FadeOut, [braces[2], words[2]]))
for x in range(20):
self.increment()
class Describe2222(Scene):
def construct(self):
ternary_mob = TexMobject("2222").scale(1.5)
brace = Brace(ternary_mob)
description = brace.get_text("$3^4 - 1 = 80$")
VGroup(ternary_mob, brace, description).scale(1.5)
self.add(ternary_mob)
self.dither()
self.play(GrowFromCenter(brace))
self.play(Write(description))
self.dither()
class KeithAsksAboutConfigurations(Scene):
def construct(self):
keith = Keith().shift(2*DOWN+3*LEFT)
morty = Mortimer().shift(2*DOWN+3*RIGHT)
keith.make_eye_contact(morty)
bubble = keith.get_bubble("speech")
bubble.write("Think about how many \\\\ configurations there are.")
self.add(keith, morty)
self.play(Blink(keith))
self.play(
keith.change_mode, "speaking",
ShowCreation(bubble),
Write(bubble.content)
)
self.play(Blink(morty))
self.play(morty.change_mode, "pondering")
self.dither()
class AskAboutConfigurations(SolveConstrainedWithTernaryCounting):
def construct(self):
question = TextMobject("How many configurations?")
question.scale(1.5)
question.to_edge(UP)
self.add(question)
for x in range(15):
self.remove(self.curr_ternary_mob)
self.dither(2)
for y in range(7):
self.increment(run_time = 0)
class AnswerConfigurationsCount(TowersOfHanoiScene):
CONFIG = {
"middle_peg_bottom" : 2.5*DOWN,
"num_disks" : 4,
"peg_height" : 1.5,
}
def construct(self):
answer = TextMobject("$3^4 = 81$ configurations")
answer.to_edge(UP)
self.add(answer)
parentheticals = self.get_parentheticals(answer)
self.prepare_disks()
for parens, disk in zip(parentheticals, reversed(list(self.disks))):
VGroup(parens, parens.brace, parens.three).highlight(disk.get_color())
self.play(
Write(parens, run_time = 1),
FadeIn(disk)
)
self.play(
ApplyMethod(
disk.next_to, self.pegs[2], UP,
run_time = 2
),
GrowFromCenter(parens.brace),
Write(parens.three, run_time = 1)
)
x_diff = disk.saved_state.get_center()[0]-disk.get_center()[0]
self.play(
disk.shift, x_diff*RIGHT
)
self.play(disk.restore)
self.dither()
def get_parentheticals(self, top_mob):
parentheticals = VGroup(*reversed([
TexMobject("""
\\left(
\\begin{array}{c}
\\text{Choices for} \\\\
\\text{disk %d}
\\end{array}
\\right)
"""%d)
for d in range(self.num_disks)
]))
parentheticals.arrange_submobjects()
parentheticals.scale_to_fit_width(2*SPACE_WIDTH-1)
parentheticals.next_to(top_mob, DOWN)
for parens in parentheticals:
brace = Brace(parens)
three = brace.get_text("$3$")
parens.brace = brace
parens.three = three
return parentheticals
def prepare_disks(self):
configuration = [1, 2, 1, 0]
for n, peg_index in enumerate(configuration):
disk_index = self.num_disks-n-1
disk = self.disks[disk_index]
top = Circle(radius = disk.get_width()/2)
inner = Circle(radius = self.peg_width/2)
inner.flip()
top.add_subpath(inner.points)
top.set_stroke(width = 0)
top.set_fill(disk.get_color())
top.rotate(np.pi/2, RIGHT)
top.move_to(disk, UP)
bottom = top.copy()
bottom.move_to(disk, DOWN)
disk.remove(disk.label)
disk.add(top, bottom, disk.label)
self.move_disk_to_peg(disk_index, peg_index, run_time = 0)
if disk_index == 0:
disk.move_to(self.pegs[peg_index].get_bottom(), DOWN)
for disk in self.disks:
disk.save_state()
disk.rotate(np.pi/30, RIGHT)
disk.next_to(self.pegs[0], UP)
self.remove(self.disks)
class ThisIsMostEfficientText(Scene):
def construct(self):
text = TextMobject("This is the most efficient solution")
text.scale_to_fit_width(2*SPACE_WIDTH - 1)
text.to_edge(DOWN)
self.play(Write(text))
self.dither(2)
class ShowSomeGraph(Scene):
def construct(self):
title = TextMobject("Graphs")
title.scale(2)
title.to_edge(UP)
nodes = VGroup(*map(Dot, [
2*LEFT,
UP,
DOWN,
2*RIGHT,
2*RIGHT+2*UP,
2*RIGHT+2*DOWN,
4*RIGHT+2*UP,
]))
edge_pairs = [
(0, 1),
(0, 2),
(1, 3),
(2, 3),
(3, 4),
(3, 5),
(4, 6),
]
edges = VGroup()
for i, j in edge_pairs:
edges.add(Line(
nodes[i].get_center(),
nodes[j].get_center(),
))
self.play(Write(title))
for mob in nodes, edges:
mob.gradient_highlight(YELLOW, MAROON_B)
self.play(ShowCreation(
mob,
submobject_mode = "lagged_start",
run_time = 2,
))
self.dither()
class SierpinskiGraphScene(Scene):
CONFIG = {
"num_disks" : 3,
"towers_config" : {
"num_disks" : 3,
"peg_height" : 1.5,
"peg_spacing" : 2,
"include_peg_labels" : False,
"disk_min_width" : 1,
"disk_max_width" : 2,
},
"node_radius" : 0.4,
"center_to_island_length" : 2.0,
"include_towers" : True,
"start_color" : RED,
"end_color" : GREEN,
"graph_stroke_width" : 2,
}
def setup(self):
self.nodes = VGroup(*[
self.create_node(node_index)
for node_index in range(3**self.num_disks)
])
circles = VGroup(*[node.circle for node in self.nodes])
circles.gradient_highlight(self.start_color, self.end_color)
circles.set_fill(BLACK, opacity = 0.7)
circles.set_stroke(width = self.graph_stroke_width)
self.nodes.center()
self.add(self.nodes)
self.edges = self.get_edges()
self.add(self.edges)
def node_index_to_coord_list(self, node_index):
assert(node_index >= 0 and node_index < 3**self.num_disks)
coord_list = []
for x in range(self.num_disks):
coord_list = [node_index%3] + coord_list
node_index /= 3
return coord_list
def create_node(self, node_index, include_towers = None):
if include_towers is None:
include_towers = self.include_towers
coords = self.node_index_to_coord_list(node_index)
node = VGroup()
center = np.array(ORIGIN)
for n, coord in enumerate(coords):
assert(coord in [0, 1, 2])
vect = rotate_vector(RIGHT, -5*np.pi/6 - coord*2*np.pi/3)
vect *= self.center_to_island_length/float(2**n)
center = center + vect
circle = Circle(radius = self.node_radius)
circle.scale(self.node_radius)
circle.shift(center)
node.circle = circle
node.add(circle)
if include_towers:
towers_scene = TowersOfHanoiScene(**self.towers_config)
towers_scene.set_disk_config(coords)
towers = VGroup(*towers_scene.get_mobjects())
towers.scale_to_fit_width(0.75*node.get_width())
towers.move_to(center)
node.towers = towers
node.add(towers)
return node
def distance_between_nodes(self, i, j):
return np.linalg.norm(
self.nodes[i].get_center()-\
self.nodes[j].get_center()
)
def get_edges(self):
edges = VGroup()
min_distance = self.distance_between_nodes(0, 1)
min_distance *= 1.1 ##Just a little buff to be sure
for i, j in it.combinations(range(3**self.num_disks), 2):
center1 = self.nodes[i].get_center()
center2 = self.nodes[j].get_center()
if np.linalg.norm(center1 - center2) < min_distance:
vect = center1-center2
edge = Line(
center1 - 2*vect*self.node_radius,
center2 + 2*vect*self.node_radius,
color = self.nodes[i].circle.get_stroke_color(),
stroke_width = self.graph_stroke_width,
)
edges.add(edge)
return edges
class IntroduceGraphStructure(SierpinskiGraphScene):
CONFIG = {
"include_towers" : True,
"graph_stroke_width" : 2,
}
def construct(self):
self.remove(self.nodes, self.edges)
self.introduce_nodes()
self.define_edges()
def introduce_nodes(self):
self.play(FadeIn(
self.nodes,
run_time = 3,
submobject_mode = "lagged_start",
lag_factor = 7,
))
vect = LEFT
for index in 3, 21, 8, 17, 10, 13:
node = self.nodes[index]
node.save_state()
self.play(
node.scale_to_fit_height, 2*SPACE_HEIGHT-2,
node.next_to, ORIGIN, vect
)
self.dither()
self.play(node.restore)
vect = -vect
def define_edges(self):
nodes = [self.nodes[i] for i in 12, 14]
for node, vect in zip(nodes, [LEFT, RIGHT]):
node.save_state()
node.generate_target()
node.target.scale_to_fit_height(2*SPACE_HEIGHT-1)
node.target.to_edge(vect)