scipy.special.y0 — SciPy v1.15.2 Manual (original) (raw)

scipy.special.y0(x, out=None) = <ufunc 'y0'>#

Bessel function of the second kind of order 0.

Parameters:

xarray_like

Argument (float).

outndarray, optional

Optional output array for the function results

Returns:

Yscalar or ndarray

Value of the Bessel function of the second kind of order 0 at x.

See also

j0

Bessel function of the first kind of order 0

yv

Bessel function of the first kind

Notes

The domain is divided into the intervals [0, 5] and (5, infinity). In the first interval a rational approximation \(R(x)\) is employed to compute,

\[Y_0(x) = R(x) + \frac{2 \log(x) J_0(x)}{\pi},\]

where \(J_0\) is the Bessel function of the first kind of order 0.

In the second interval, the Hankel asymptotic expansion is employed with two rational functions of degree 6/6 and 7/7.

This function is a wrapper for the Cephes [1] routine y0.

References

Examples

Calculate the function at one point:

from scipy.special import y0 y0(1.) 0.08825696421567697

Calculate at several points:

import numpy as np y0(np.array([0.5, 2., 3.])) array([-0.44451873, 0.51037567, 0.37685001])

Plot the function from 0 to 10.

import matplotlib.pyplot as plt fig, ax = plt.subplots() x = np.linspace(0., 10., 1000) y = y0(x) ax.plot(x, y) plt.show()

../../_images/scipy-special-y0-1.png