def generate_points(self):
start_angle = np.pi / 2 + self.arc_angle / 2
end_angle = np.pi / 2 - self.arc_angle / 2
self.add(Arc(start_angle=start_angle, angle=-self.arc_angle))
tick_angle_range = np.linspace(start_angle, end_angle, self.num_ticks)
for index, angle in enumerate(tick_angle_range):
vect = rotate_vector(RIGHT, angle)
tick = Line((1 - self.tick_length) * vect, vect)
label = TexMobject(str(10 * index))
label.set_height(self.tick_length)
label.shift((1 + self.tick_length) * vect)
self.add(tick, label)
needle = Polygon(LEFT,
UP,
RIGHT,
stroke_width=0,
fill_opacity=1,
fill_color=self.needle_color)
needle.stretch_to_fit_width(self.needle_width)
needle.stretch_to_fit_height(self.needle_height)
needle.rotate(start_angle - np.pi / 2, about_point=ORIGIN)
self.add(needle)
self.needle = needle
self.center_offset = self.get_center()
def add_brackets(self):
bracket_pair = TexMobject("\\big[ \\big]")
bracket_pair.scale(2)
bracket_pair.stretch_to_fit_height(self.get_height() + 0.5)
l_bracket, r_bracket = bracket_pair.split()
l_bracket.next_to(self, LEFT)
r_bracket.next_to(self, RIGHT)
self.add(l_bracket, r_bracket)
self.brackets = VGroup(l_bracket, r_bracket)
return self
def generate_sea_of_zeros(self):
zero = TexMobject("0")
self.sea_of_zeros = []
for n in range(self.nrows):
for a in range((self.nrows - n) / 2 + 1):
for k in (n + a + 1, -a - 1):
self.coords.append((n, k))
mob = zero.copy()
mob.shift(self.coords_to_center(n, k))
self.coords_to_mobs[n][k] = mob
self.add(mob)
return self
def get_result_matrix(self, left, right):
(m, k), n = left.shape, right.shape[1]
mob_matrix = np.array([VGroup()]).repeat(m * n).reshape((m, n))
for a in range(m):
for b in range(n):
template = "(%s)(%s)" if self.use_parens else "%s%s"
parts = [
prefix + template % (left[a][c], right[c][b])
for c in range(k) for prefix in ["" if c == 0 else "+"]
]
mob_matrix[a][b] = TexMobject(parts, next_to_buff=0.1)
return Matrix(mob_matrix)
def get_det_text(matrix,
determinant=None,
background_rect=True,
initial_scale_factor=2):
parens = TexMobject(["(", ")"])
parens.scale(initial_scale_factor)
parens.stretch_to_fit_height(matrix.get_height())
l_paren, r_paren = parens.split()
l_paren.next_to(matrix, LEFT, buff=0.1)
r_paren.next_to(matrix, RIGHT, buff=0.1)
det = TextMobject("det")
det.scale(initial_scale_factor)
det.next_to(l_paren, LEFT, buff=0.1)
if background_rect:
det.add_background_rectangle()
det_text = VMobject(det, l_paren, r_paren)
if determinant is not None:
eq = TexMobject("=")
eq.next_to(r_paren, RIGHT, buff=0.1)
result = TexMobject(str(determinant))
result.next_to(eq, RIGHT, buff=0.2)
det_text.add(eq, result)
return det_text
def generate_n_choose_k_mobs(self):
self.coords_to_n_choose_k = {}
for n, k in self.coords:
nck_mob = TexMobject(r"{%d \choose %d}" % (n, k))
scale_factor = min(
1,
self.portion_to_fill * self.cell_height / nck_mob.get_height(),
self.portion_to_fill * self.cell_width / nck_mob.get_width(),
)
center = self.coords_to_mobs[n][k].get_center()
nck_mob.center().scale(scale_factor).shift(center)
if n not in self.coords_to_n_choose_k:
self.coords_to_n_choose_k[n] = {}
self.coords_to_n_choose_k[n][k] = nck_mob
return self
def count_mobjects(self,
mobjects,
mode="highlight",
color="red",
display_numbers=True,
num_offset=DEFAULT_COUNT_NUM_OFFSET,
run_time=DEFAULT_COUNT_RUN_TIME):
"""
Note, leaves final number mobject as "number" attribute
mode can be "highlight", "show_creation" or "show", otherwise
a warning is given and nothing is animating during the count
"""
if len(mobjects) > 50: #TODO
raise Exception("I don't know if you should be counting \
too many mobjects...")
if len(mobjects) == 0:
raise Exception("Counting mobject list of length 0")
if mode not in ["highlight", "show_creation", "show"]:
raise Warning("Unknown mode")
frame_time = run_time / len(mobjects)
if mode == "highlight":
self.add(*mobjects)
for mob, num in zip(mobjects, it.count(1)):
if display_numbers:
num_mob = TexMobject(str(num))
num_mob.center().shift(num_offset)
self.add(num_mob)
if mode == "highlight":
original_color = mob.color
mob.set_color(color)
self.wait(frame_time)
mob.set_color(original_color)
if mode == "show_creation":
self.play(ShowCreation(mob, run_time=frame_time))
if mode == "show":
self.add(mob)
self.wait(frame_time)
if display_numbers:
self.remove(num_mob)
if display_numbers:
self.add(num_mob)
self.number = num_mob
return self
def count_regions(self,
regions,
mode="one_at_a_time",
num_offset=DEFAULT_COUNT_NUM_OFFSET,
run_time=DEFAULT_COUNT_RUN_TIME,
**unused_kwargsn):
if mode not in ["one_at_a_time", "show_all"]:
raise Warning("Unknown mode")
frame_time = run_time / (len(regions))
for region, count in zip(regions, it.count(1)):
num_mob = TexMobject(str(count))
num_mob.center().shift(num_offset)
self.add(num_mob)
self.set_color_region(region)
self.wait(frame_time)
if mode == "one_at_a_time":
self.reset_background()
self.remove(num_mob)
self.add(num_mob)
self.number = num_mob
return self
def organize_matrices(self, left, right, result):
equals = TexMobject("=")
everything = VGroup(left, right, equals, result)
everything.arrange_submobjects()
everything.set_width(FRAME_WIDTH - 1)
self.add(everything)
def matrix_to_mobject(matrix):
return TexMobject(matrix_to_tex_string(matrix))