def kelvin_zeros(nt):
    """Compute nt zeros of all the kelvin functions returned in a
    length 8 tuple of arrays of length nt.
    The tuple containse the arrays of zeros of
    (ber, bei, ker, kei, ber', bei', ker', kei')
    """
    if not isscalar(nt) or (floor(nt)!=nt) or (nt<=0):
        raise ValueError("nt must be positive integer scalar.")
    return specfun.klvnzo(nt,1), \
           specfun.klvnzo(nt,2), \
           specfun.klvnzo(nt,3), \
           specfun.klvnzo(nt,4), \
           specfun.klvnzo(nt,5), \
           specfun.klvnzo(nt,6), \
           specfun.klvnzo(nt,7), \
           specfun.klvnzo(nt,8)

def keip_zeros(nt):
    """Compute nt zeros of the kelvin function kei' x
    """
    if not isscalar(nt) or (floor(nt)!=nt) or (nt<=0):
        raise ValueError("nt must be positive integer scalar.")
    return specfun.klvnzo(nt,8)