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.scale_to_fit_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)
self.add(needle)
self.needle = needle
self.center_offset = self.get_center()
def show_angles(self):
words = TextMobject("""
Let's see what happens as we change
the angle in this seed
""")
words.to_edge(UP)
koch, sharper_koch, duller_koch = curves = [
CurveClass(order=1)
for CurveClass in StraightKoch, SharperKoch, DullerKoch
]
arcs = [
Arc(2 * (np.pi / 2 - curve.angle),
radius=r,
start_angle=np.pi + curve.angle).shift(
curve.points[curve.get_num_points() / 2])
for curve, r in zip(curves, [0.6, 0.7, 0.4])
]
theta = TexMobject("\\theta")
theta.shift(arcs[0].get_center() + 2.5 * DOWN)
arrow = Arrow(theta, arcs[0])
self.add(words, koch)
self.play(ShowCreation(arcs[0]))
self.play(ShowCreation(arrow), ShimmerIn(theta))
self.wait(2)
self.remove(theta, arrow)
self.play(
Transform(koch, duller_koch),
Transform(arcs[0], arcs[2]),
)
self.play(
Transform(koch, sharper_koch),
Transform(arcs[0], arcs[1]),
)
self.clear()