3b1b-manim/manimlib/mobject/functions.py

83 lines
2.4 KiB
Python

from manimlib.constants import *
from manimlib.mobject.types.vectorized_mobject import VMobject
from manimlib.utils.config_ops import digest_config
class ParametricFunction(VMobject):
CONFIG = {
"t_min": 0,
"t_max": 1,
# TODO, be smarter about choosing this number
"step_size": 0.01,
"dt": 1e-8,
# TODO, be smar about figuring these out?
"discontinuities": [],
}
def __init__(self, function, **kwargs):
self.function = function
VMobject.__init__(self, **kwargs)
def get_function(self):
return self.function
def get_point_from_function(self, t):
return self.function(t)
def generate_points(self):
t_min, t_max = self.t_min, self.t_max
dt = self.dt
step_size = self.step_size
discontinuities = filter(
lambda t: t_min <= t <= t_max,
self.discontinuities
)
discontinuities = np.array(list(discontinuities))
boundary_times = [
self.t_min, self.t_max,
*(discontinuities - dt),
*(discontinuities + dt),
]
boundary_times.sort()
for t1, t2 in zip(boundary_times[0::2], boundary_times[1::2]):
t_range = list(np.arange(t1, t2, step_size))
if t_range[-1] != t2:
t_range.append(t2)
points = np.array([self.function(t) for t in t_range])
valid_indices = np.apply_along_axis(
np.all, 1, np.isfinite(points)
)
points = points[valid_indices]
if len(points) > 0:
self.start_new_path(points[0])
self.add_points_as_corners(points[1:])
self.make_smooth()
return self
class FunctionGraph(ParametricFunction):
CONFIG = {
"color": YELLOW,
"x_min": -FRAME_X_RADIUS,
"x_max": FRAME_X_RADIUS,
}
def __init__(self, function, **kwargs):
digest_config(self, kwargs)
self.parametric_function = \
lambda t: np.array([t, function(t), 0])
ParametricFunction.__init__(
self,
self.parametric_function,
t_min=self.x_min,
t_max=self.x_max,
**kwargs
)
self.function = function
def get_function(self):
return self.function
def get_point_from_function(self, x):
return self.parametric_function(x)