sph.py 文件源码

def spbessel(n, kr):
    """Spherical Bessel function (first kind) of order n at kr

    Parameters
    ----------
    n : array_like
       Order
    kr: array_like
       Argument

    Returns
    -------
    J : complex float
       Spherical Bessel
    """
    n, kr = scalar_broadcast_match(n, kr)

    if _np.any(n < 0) | _np.any(kr < 0) | _np.any(_np.mod(n, 1) != 0):
        J = _np.zeros(kr.shape, dtype=_np.complex_)

        kr_non_zero = kr != 0
        J[kr_non_zero] = _np.lib.scimath.sqrt(_np.pi / 2 / kr[kr_non_zero]) * besselj(n[kr_non_zero] + 0.5, kr[kr_non_zero])
        J[_np.logical_and(kr == 0, n == 0)] = 1
    else:
        J = scy.spherical_jn(n.astype(_np.int), kr)
    return _np.squeeze(J)