3b1b-manim/utils/simple_functions.py

39 lines
1,019 B
Python

import numpy as np
import operator as op
import inspect
from functools import reduce
def sigmoid(x):
return 1.0 / (1 + np.exp(-x))
def choose(n, r):
if n < r:
return 0
if r == 0:
return 1
denom = reduce(op.mul, range(1, r + 1), 1)
numer = reduce(op.mul, range(n, n - r, -1), 1)
return numer // denom
def get_num_args(function):
return len(inspect.signature(function).parameters)
# Just to have a less heavyweight name for this extremely common operation
#
# We may wish to have more fine-grained control over division by zero behavior
# in the future (separate specifiable values for 0/0 and x/0 with x != 0),
# but for now, we just allow the option to handle indeterminate 0/0.
def fdiv(a, b, zero_over_zero_value=None):
if zero_over_zero_value is not None:
out = np.full_like(a, zero_over_zero_value)
where = np.logical_or(a != 0, b != 0)
else:
out = None
where = True
return np.true_divide(a, b, out=out, where=where)