A few changes during Fourier project

This commit is contained in:
Grant Sanderson
2018-01-15 18:49:58 -08:00
parent bb2956dbae
commit 0da39a421e
3 changed files with 113 additions and 25 deletions

View File

@ -519,7 +519,7 @@ class Quadrant(Mobject1D):
CONFIG = {
"radius" : 2,
"stroke_width": 2,
"density" : 75,
"density" : 45,
}
def generate_points(self):
self.add_points([
@ -541,11 +541,8 @@ class UnmixMixedPaint(Scene):
quadrants.ingest_submobjects()
quadrants.sort_points(lambda p : np.random.random())
start_rgbas = np.array(quadrants.rgbas)
target_rgbas = np.zeros(start_rgbas.shape)
mud_color = average_color(*self.colors)
target_rgbas[:,:] = color_to_rgba(mud_color)
mud_color = average_color(*self.colors)
background_circle = Circle(
radius = 2,
stroke_width = 0,
@ -553,28 +550,111 @@ class UnmixMixedPaint(Scene):
fill_opacity = 1
)
def update_color(quadrants, alpha):
quadrants.rgbas = interpolate(start_rgbas, target_rgbas, alpha)
# start_rgbas = np.array(quadrants.rgbas)
# target_rgbas = np.zeros(start_rgbas.shape)
# target_rgbas[:,:] = color_to_rgba(mud_color)
# def update_color(quadrants, alpha):
# quadrants.rgbas = interpolate(start_rgbas, target_rgbas, alpha)
self.add(background_circle, quadrants)
dot = Dot()
permutation = range(len(quadrants.points))
random.shuffle(permutation)
def update_quadrants(quadrants, alpha):
points = quadrants.points
points += dot.get_center()
points[:,0] -= points[:,1]
points -= dot.get_center()
quadrants.points = interpolate(
quadrants.points, quadrants.points[permutation],
0.01,
)
self.add(quadrants)
self.play(
PhaseFlow(
lambda p : rotate_vector(p, np.pi/2+0.01)/(max(np.linalg.norm(p), 0.001)),
quadrants,
virtual_time = 20,
),
UpdateFromAlphaFunc(quadrants, update_color),
run_time = 10,
# PhaseFlow(
# lambda p : rotate_vector(p, np.pi/2+0.01)/(max(np.linalg.norm(p), 0.001)),
# quadrants,
# virtual_time = 20,
# ),
# UpdateFromAlphaFunc(quadrants, update_color),
UpdateFromAlphaFunc(quadrants, update_quadrants),
run_time = 3,
)
#Incomplete, and probably not useful
class MachineThatTreatsOneFrequencyDifferently(Scene):
def construct(self):
graph = self.get_cosine_graph(0.5)
frequency_mob = DecimalNumber(220, num_decimal_points = 0)
frequency_mob.next_to(graph, UP, buff = MED_LARGE_BUFF)
self.graph = graph
self.frequency_mob = frequency_mob
self.add(graph, frequency_mob)
arrow1, q_marks, arrow2 = group = VGroup(
Vector(DOWN), TextMobject("???").scale(1.5), Vector(DOWN)
)
group.highlight(WHITE)
group.arrange_submobjects(DOWN)
group.next_to(graph, DOWN)
self.add(group)
self.change_graph_frequency(1)
graph.highlight(GREEN)
self.dither()
graph.highlight(YELLOW)
self.change_graph_frequency(2)
self.dither()
def change_graph_frequency(self, frequency, run_time = 2):
graph = self.graph
frequency_mob = self.frequency_mob
curr_frequency = graph.frequency
self.play(
UpdateFromAlphaFunc(
graph, self.get_signal_update_func(graph, frequency),
),
ChangingDecimal(
frequency_mob,
lambda a : 440*interpolate(curr_frequency, frequency, a)
),
run_time = run_time,
)
graph.frequency = frequency
def get_signal_update_func(self, graph, target_frequency):
curr_frequency = graph.frequency
def update(graph, alpha):
frequency = interpolate(curr_frequency, target_frequency, alpha)
new_graph = self.get_cosine_graph(frequency)
Transform(graph, new_graph).update(1)
return graph
return update
def get_cosine_graph(self, frequency, num_steps = 200, color = YELLOW):
result = FunctionGraph(
lambda x : 0.5*np.cos(2*np.pi*frequency*x),
num_steps = num_steps
)
result.frequency = frequency
result.shift(2*UP)
return result
class FourierMachineScene(Scene):
CONFIG = {
}
def get_time_graph_axes(self):
pass
class FourierMachineSceneTest(FourierMachineScene):
def construct(self):
pass

View File

@ -50,3 +50,13 @@ class WriteStuff(Scene):
self.play(Write(TextMobject("Stuff").scale(3)))

View File

@ -43,8 +43,6 @@ class Integer(VGroup):
if num_str[0] == "-":
self[0].next_to(self[1], LEFT, buff = SMALL_BUFF)
#Todo, this class is now broken
class ChangingDecimal(Animation):
CONFIG = {
"num_decimal_points" : None,