sph.py 文件源码

def dsphankel2(n, kr):
    """Derivative spherical Hankel (second kind) of order n at kr

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

    Returns
    -------
    dhn2 : complex float
       Derivative of spherical Hankel function hn' (second kind)
    """
    n, kr = scalar_broadcast_match(n, kr)
    dhn2 = _np.full(n.shape, _np.nan, dtype=_np.complex_)
    kr_nonzero = kr != 0
    dhn2[kr_nonzero] = 0.5 * (sphankel2(n[kr_nonzero] - 1, kr[kr_nonzero]) - sphankel2(n[kr_nonzero] + 1, kr[kr_nonzero]) - sphankel2(n[kr_nonzero], kr[kr_nonzero]) / kr[kr_nonzero])
    return dhn2