public-mirrors/3b1b-manim
1
0
Fork 0
mirror of https://github.com/3b1b/manim.git synced 2025-09-01 00:48:45 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

Improved how functions are drawn

Browse source
This commit is contained in:
Grant Sanderson 2018-01-18 16:46:38 -08:00
parent b0d85e4cbe
commit 7cbc83df20
2 changed files with 41 additions and 39 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

63
topics/functions.py
View file

@ -4,50 +4,47 @@ from mobject.vectorized_mobject import VMobject
from helpers import *
class FunctionGraph(VMobject):
CONFIG = {
"color" : YELLOW,
"x_min" : -SPACE_WIDTH,
"x_max" : SPACE_WIDTH,
"num_steps" : 20,
}
def __init__(self, function, **kwargs):
self.function = function
VMobject.__init__(self, **kwargs)
def generate_points(self):
x_values = np.linspace(self.x_min, self.x_max, self.num_steps)
y_values = self.function(x_values)
okay_indices = np.isfinite(y_values)
x_values = x_values[okay_indices]
y_values = y_values[okay_indices]
self.set_anchor_points([
x*RIGHT + y*UP
for x, y in zip(x_values, y_values)
], mode = "smooth")
def get_function(self):
return self.function
class ParametricFunction(VMobject):
CONFIG = {
"t_min" : 0,
"t_max" : 1,
"num_anchor_points" : 10,
"num_anchor_points" : 100,
}
def __init__(self, function, **kwargs):
self.function = function
VMobject.__init__(self, **kwargs)
def generate_points(self):
t_values = np.linspace(
self.t_min, self.t_max, self.num_anchor_points
n_points = 3*self.num_anchor_points - 2
self.points = np.zeros((n_points, self.dim))
self.points[:,0] = np.linspace(
self.t_min, self.t_max, n_points
)
points = np.array(map(self.function, t_values))
okay_indices = np.apply_along_axis(np.all, 1, np.isfinite(points))
points = points[okay_indices]
self.set_anchor_points(points, mode = "smooth")
#VMobject.apply_function takes care of preserving
#desirable tangent line properties at anchor points
self.apply_function(lambda p : self.function(p[0]))
class FunctionGraph(ParametricFunction):
CONFIG = {
"color" : YELLOW,
"x_min" : -SPACE_WIDTH,
"x_max" : SPACE_WIDTH,
}
def __init__(self, function, **kwargs):
digest_config(self, kwargs)
parametric_function = lambda t : t*RIGHT + function(t)*UP
ParametricFunction.__init__(
self,
parametric_function,
t_min = self.x_min,
t_max = self.x_max,
**kwargs
)
self.function = function
def get_function(self):
return self.function

17
topics/number_line.py
View file

@ -4,6 +4,7 @@ from mobject import Mobject1D
from mobject.vectorized_mobject import VMobject, VGroup
from mobject.tex_mobject import TexMobject
from topics.geometry import Line, Arrow
from topics.functions import ParametricFunction
from scene import Scene
class NumberLine(VMobject):
@ -162,6 +163,7 @@ class Axes(VGroup):
"z_min" : -3.5,
"z_max" : 3.5,
"z_normal" : DOWN,
"default_num_graph_points" : 100,
}
def __init__(self, **kwargs):
VGroup.__init__(self, **kwargs)
@ -192,13 +194,16 @@ class Axes(VGroup):
self.y_axis.point_to_number(point),
)
def get_graph(self, function, num_graph_points = 40, **kwargs):
def get_graph(self, function, num_graph_points = None, **kwargs):
kwargs["fill_opacity"] = kwargs.get("fill_opacity", 0)
graph = VMobject(**kwargs)
graph.set_points_smoothly([
self.coords_to_point(x, function(x))
for x in np.linspace(self.x_min, self.x_max, num_graph_points)
])
kwargs["num_anchor_points"] = \
num_graph_points or self.default_num_graph_points
graph = ParametricFunction(
lambda t : self.coords_to_point(t, function(t)),
t_min = self.x_min,
t_max = self.x_max,
**kwargs
)
graph.underlying_function = function
return graph