scipy.special.cosm1 — SciPy v1.15.2 Manual (original) (raw)

scipy.special.cosm1(x, out=None) = <ufunc 'cosm1'>#

cos(x) - 1 for use when x is near zero.

Parameters:

xarray_like

Real valued argument.

outndarray, optional

Optional output array for the function results.

Returns:

scalar or ndarray

Values of cos(x) - 1.

Examples

import numpy as np import scipy.special as sc

It is more accurate than computing cos(x) - 1 directly forx around 0.

x = 1e-30 np.cos(x) - 1 0.0 sc.cosm1(x) -5.0000000000000005e-61