# scipy.special.y1¶

scipy.special.y1(x) = <ufunc 'y1'>

Bessel function of the second kind of order 1.

Parameters
xarray_like

Argument (float).

Returns
Yndarray

Value of the Bessel function of the second kind of order 1 at x.

Notes

The domain is divided into the intervals [0, 8] and (8, infinity). In the first interval a 25 term Chebyshev expansion is used, and computing $$J_1$$ (the Bessel function of the first kind) is required. In the second, the asymptotic trigonometric representation is employed using two rational functions of degree 5/5.

This function is a wrapper for the Cephes [1] routine y1.

References

1

Cephes Mathematical Functions Library, http://www.netlib.org/cephes/

scipy.special.y0

scipy.special.i0