Merge pull request #176 from 3b1b/winding-number-grant

Winding number grant
This commit is contained in:
Grant Sanderson 2018-03-26 11:02:17 -07:00 committed by GitHub
commit 873fa49fbe
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
3 changed files with 291 additions and 13 deletions

View file

@ -619,7 +619,8 @@ def walker_animation_with_display(
display.background_rectangle.fill_color = GREY
display.background_rectangle.scale(1.2)
displaycement = 0.5 * DOWN # How about that pun, eh?
display.move_to(walker.get_center() + displaycement)
# display.move_to(walker.get_center() + displaycement)
display.next_to(walker, DOWN+RIGHT, SMALL_BUFF)
display_anim = ChangingDecimal(display,
number_update_func,
tracked_mobject = walker_anim.compound_walker.walker,

View file

@ -1928,6 +1928,20 @@ class TinyLoopAroundRed(TinyLoop):
"target_coords" : (-1, 1),
}
class ConfusedPiCreature(PiCreatureScene):
def construct(self):
morty = self.pi_creature
morty.set_color(YELLOW_E)
morty.flip()
morty.center()
self.play(morty.change, "awe", DOWN+3*RIGHT)
self.wait(2)
self.play(morty.change, "confused")
self.wait(2)
self.play(morty.change, "pondering")
self.wait(2)
class FailureOfComposition(ColorMappedObjectsScene):
CONFIG = {
"func" : lambda p : (
@ -2180,7 +2194,11 @@ class TransitionFromPathsToBoundaries(ColorMappedObjectsScene):
CONFIG = {
"func" : plane_func_by_wind_spec(
(-2, 0, 2), (2, 0, 1)
)
),
"dot_fill_opacity" : 1,
"dot_stroke_width" : 1,
"include_walkers" : True,
"include_question_mark" : True,
}
def construct(self):
ColorMappedObjectsScene.construct(self)
@ -2210,7 +2228,10 @@ class TransitionFromPathsToBoundaries(ColorMappedObjectsScene):
#Setup region labels
for square, tex in (left_square, "x"), (right_square, "y"), (joint_rect, "x+y \\, ?"):
sum_tex = "x+y"
if self.include_question_mark:
sum_tex += "\\, ?"
for square, tex in (left_square, "x"), (right_square, "y"), (joint_rect, sum_tex):
square.label = TextMobject("Winding = ", "$%s$"%tex)
square.label.move_to(square)
@ -2264,7 +2285,7 @@ class TransitionFromPathsToBoundaries(ColorMappedObjectsScene):
path_arc = TAU/6
),
FadeIn(joint_rect.label[1][1]),
FadeIn(joint_rect.label[1][3]),
FadeIn(joint_rect.label[1][3:]),
FadeOut(right_square.label[0]),
Transform(
right_square.label[1], joint_rect.label[1][2],
@ -2313,9 +2334,12 @@ class TransitionFromPathsToBoundaries(ColorMappedObjectsScene):
#Setup dot, arrow and label
dot = self.dot = Dot(radius = 0.1)
dot.set_stroke(WHITE, 1)
dot.set_stroke(WHITE, self.dot_stroke_width)
update_dot_color = ContinualUpdateFromFunc(
dot, lambda d : d.set_fill(get_output_color())
dot, lambda d : d.set_fill(
get_output_color(),
self.dot_fill_opacity
)
)
label = DecimalNumber(0, num_decimal_points = 1)
@ -2326,7 +2350,7 @@ class TransitionFromPathsToBoundaries(ColorMappedObjectsScene):
arrow_length = 0.75
arrow = Vector(arrow_length*RIGHT)
arrow.set_stroke(WHITE, 1)
arrow.set_stroke(WHITE, self.dot_stroke_width)
def arrow_update_func(arrow):
arrow.set_fill(get_output_color(), 1)
arrow.rotate(-TAU*get_output_rev() - arrow.get_angle())
@ -2335,7 +2359,8 @@ class TransitionFromPathsToBoundaries(ColorMappedObjectsScene):
return arrow
update_arrow = ContinualUpdateFromFunc(arrow, arrow_update_func)
self.add(update_arrow, update_dot_color, label_upadte)
if self.include_walkers:
self.add(update_arrow, update_dot_color, label_upadte)
return dot
def position_dot(self, point):
@ -2343,6 +2368,17 @@ class TransitionFromPathsToBoundaries(ColorMappedObjectsScene):
self.start_rev = self.get_output_rev()
self.curr_winding = 0
class TransitionFromPathsToBoundariesArrowless(TransitionFromPathsToBoundaries):
CONFIG = {
"func" : plane_func_by_wind_spec(
(-2, 0, 2), (2, 0, 1)
),
"dot_fill_opacity" : 0,
"dot_stroke_width" : 0,
"include_walkers" : False,
"include_question_mark" : False,
}
class BreakDownLoopWithNonzeroWinding(TransitionFromPathsToBoundaries):
def construct(self):
zero_point = 2*LEFT
@ -2621,9 +2657,7 @@ class PolynomialTerms(MonomialTerm):
class SearchSpacePerimeterVsArea(EquationSolver2d):
CONFIG = {
"func" : plane_func_by_wind_spec(
(-3, -1.3, 2), (0.1, 0.2, 1), (2.8, -2, 1)
),
"func" : example_plane_func,
"num_iterations" : 15,
"display_in_parallel" : False,
"use_fancy_lines" : True,
@ -2686,6 +2720,223 @@ class SearchSpacePerimeterVsArea(EquationSolver2d):
self.play(FadeOut(full_rect))
self.wait()
class ShowPolynomialFinalState(SolveX5MinusXMinus1):
CONFIG = {
"num_iterations" : 15,
}
def construct(self):
self.force_skipping()
SolveX5MinusXMinus1.construct(self)
self.revert_to_original_skipping_status()
class PiCreatureInAwe(Scene):
def construct(self):
randy = Randolph()
self.play(randy.change, "awe")
self.play(Blink(randy))
self.play(randy.look, UP, run_time = 2)
self.play(
randy.look, RIGHT,
run_time = 4,
rate_func = there_and_back,
path_arc = -TAU/4
)
self.wait()
class ShowComplexFunction(Scene):
def construct(self):
plane = ComplexPlane()
plane.add_coordinates()
four_i = plane.coordinate_labels[-1]
plane.coordinate_labels.remove(four_i)
plane.remove(four_i)
title = TextMobject("Complex Plane")
title.to_edge(UP, buff = MED_SMALL_BUFF)
rect = BackgroundRectangle(title, fill_opacity = 1, buff = MED_SMALL_BUFF)
x = complex(1, 0.4)
f = lambda x : x**5 - x - 1
x_point = plane.number_to_point(x)
fx_point = plane.number_to_point(f(x))
x_dot = Dot(x_point)
fx_dot = Dot(fx_point, color = YELLOW)
arrow = Arrow(
x_point, fx_point,
use_rectangular_stem = False,
path_arc = TAU/3,
color = YELLOW
)
arrow.pointwise_become_partial(arrow, 0, 0.95)
x_label = TexMobject("x = %d+%.1fi"%(x.real, x.imag))
x_label.next_to(x_dot, RIGHT)
x_label.add_background_rectangle()
fx_label = TexMobject("f(x) = x^5 - x - 1")
fx_label.next_to(fx_dot, DOWN, SMALL_BUFF)
fx_label.highlight(YELLOW)
fx_label.add_background_rectangle()
fx_label.generate_target()
fx_label.target.move_to(title)
fx_label.target[1].highlight(WHITE)
self.play(
Write(plane),
FadeIn(rect),
LaggedStart(FadeIn, title)
)
self.play(*map(FadeIn, [x_dot, x_label]))
self.wait()
self.play(
ReplacementTransform(x_dot.copy(), fx_dot, path_arc = arrow.path_arc),
ShowCreation(arrow, rate_func = squish_rate_func(smooth, 0.2, 1))
)
self.play(FadeIn(fx_label))
self.wait(2)
self.play(
MoveToTarget(fx_label),
*map(FadeOut, [title, x_dot, x_label, arrow, fx_dot])
)
self.play(FadeOut(plane.coordinate_labels))
self.wait()
class WindingNumbersInInputOutputContext(PathContainingZero):
CONFIG = {
"in_loop_center_coords" : (-2, -1),
"run_time" : 10,
}
def construct(self):
self.remove(self.pi_creature)
self.setup_planes()
in_loop = Circle()
in_loop.flip(RIGHT)
# in_loop = Square(side_length = 2)
in_loop.insert_n_anchor_points(100)
in_loop.move_to(self.input_plane.coords_to_point(
*self.in_loop_center_coords
))
in_loop.match_background_image_file(self.input_coloring)
out_loop = in_loop.copy()
out_loop.match_background_image_file(self.output_coloring)
update_out_loop = ContinualUpdateFromFunc(
out_loop,
lambda m : m.set_points(in_loop.points).apply_function(self.point_function)
)
# self.add(update_out_loop)
in_dot = Dot(radius = 0.04)
update_in_dot = ContinualUpdateFromFunc(
in_dot, lambda d : d.move_to(in_loop.point_from_proportion(1))
)
self.add(update_in_dot)
out_arrow = Arrow(LEFT, RIGHT)
update_out_arrow = ContinualUpdateFromFunc(
out_arrow,
lambda a : a.put_start_and_end_on(
self.output_plane.coords_to_point(0, 0),
out_loop.point_from_proportion(1)
)
)
update_out_arrow_color = ContinualUpdateFromFunc(
out_arrow,
lambda a : a.highlight(rev_to_color(a.get_angle()/TAU))
)
self.add(update_out_arrow, update_out_arrow_color)
words = TextMobject(
"How many times does \\\\ the output wind around?"
)
label = self.output_plane.label
words.move_to(label, UP)
self.output_plane.remove(label)
self.add(words)
decimal = DecimalNumber(0)
decimal.next_to(self.output_plane.get_corner(UP+RIGHT), DOWN+LEFT)
self.play(
ShowCreation(in_loop),
ShowCreation(out_loop),
ChangeDecimalToValue(decimal, 2),
Animation(in_dot),
run_time = self.run_time,
rate_func = bezier([0, 0, 1, 1])
)
class SolveX5SkipToEnd(SolveX5MinusXMinus1):
CONFIG = {
"num_iterations" : 4,
}
def construct(self):
self.force_skipping()
SolveX5MinusXMinus1.construct(self)
self.revert_to_original_skipping_status()
mobjects = VGroup(*self.get_mobjects())
lines = VGroup()
rects = VGroup()
for mob in mobjects:
if mob.background_image_file is not None:
mob.set_stroke(width = 2)
lines.add(mob)
elif isinstance(mob, Polygon):
rects.add(mob)
else:
self.remove(mob)
self.clear()
self.add(lines, rects)
class ZeroFoundOnBoundary(Scene):
def construct(self):
arrow = Vector(DOWN+LEFT, color = WHITE)
words = TextMobject("Found zero on boundary!")
words.next_to(arrow.get_start(), UP)
words.shift(1.5*RIGHT)
point = VectorizedPoint()
point.next_to(arrow, DOWN+LEFT)
self.play(Flash(point))
self.play(
GrowArrow(arrow),
Write(words),
)
self.wait()
class AllOfTheVideos(Scene):
CONFIG = {
"camera_config" : {
"background_alpha" : 255,
}
}
def construct(self):
thumbnail_dir = os.path.join(MEDIA_DIR, "3b1b_videos/Winding/OldThumbnails")
n = 4
images = Group(*[
ImageMobject(os.path.join(thumbnail_dir, file))
for file in os.listdir(thumbnail_dir)[:n**2]
])
for image in images:
rect = SurroundingRectangle(image, buff = 0)
rect.set_stroke(WHITE, 1)
image.add(rect)
images.arrange_submobjects_in_grid(n, n, buff = 0)
images.scale_to_fit_height(2*SPACE_HEIGHT)
random.shuffle(images.submobjects)
self.play(LaggedStart(FadeIn, images, run_time = 4))
self.wait()
class EndingCredits(Scene):
def construct(self):
text = TextMobject(
@ -2999,8 +3250,33 @@ class EndScreen(PatreonEndScreen, PiCreatureScene):
self.play(morty.change, mode)
self.wait(2)
class Thumbnail(SearchSpacePerimeterVsArea):
CONFIG = {
"num_iterations" : 18,
"func" : plane_func_by_wind_spec(
(-3, -1.3, 2), (0.1, 0.2, 1), (2.8, -2, 1)
),
}
def construct(self):
self.force_skipping()
EquationSolver2d.construct(self)
self.revert_to_original_skipping_status()
mobjects = VGroup(*self.get_mobjects())
lines = VGroup()
rects = VGroup()
get_length = lambda mob : max(mob.get_width(), mob.get_height())
for mob in mobjects:
if mob.background_image_file is not None:
mob.set_stroke(width = 4*np.sqrt(get_length(mob)))
lines.add(mob)
elif isinstance(mob, Polygon):
rects.add(mob)
else:
self.remove(mob)
self.clear()
self.add(lines)

View file

@ -216,6 +216,7 @@ class ComplexPlane(NumberPlane):
num_mob.scale_to_fit_height(self.written_coordinate_height)
num_mob.next_to(point, DOWN+LEFT, SMALL_BUFF)
result.add(num_mob)
self.coordinate_labels = result
return result
def add_coordinates(self, *numbers):