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

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

Kelvin function bei.

Defined as

\[\mathrm{bei}(x) = \Im[J_0(x e^{3 \pi i / 4})]\]

where \(J_0\) is the Bessel function of the first kind of order zero (see jv). See [dlmf] for more details.

Parameters:

xarray_like

Real argument.

outndarray, optional

Optional output array for the function results.

Returns:

scalar or ndarray

Values of the Kelvin function.

See also

ber

the corresponding real part

beip

the derivative of bei

jv

Bessel function of the first kind

References

Examples

It can be expressed using Bessel functions.

import numpy as np import scipy.special as sc x = np.array([1.0, 2.0, 3.0, 4.0]) sc.jv(0, x * np.exp(3 * np.pi * 1j / 4)).imag array([0.24956604, 0.97229163, 1.93758679, 2.29269032]) sc.bei(x) array([0.24956604, 0.97229163, 1.93758679, 2.29269032])