'Cumulative sum along axis.'

def cumsum(self, axis, temp=None, target=None):

    (m, n) = self.shape
    assert (axis == 0), 'axis    =    1    not    implemented.'
    if (not target):
        target = empty((m, n))
    if (not temp):
        temp = empty((m, n))
    '    \n                elif    axis    ==    1:\n                        if    not    target:\n                                target    =    empty((m,    1))\n                '
    err_code = _eigenmat.cumsum_by_axis(self.p_mat, target.p_mat, temp.p_mat, ct.c_int(axis))
    if err_code:
        raise generate_exception(err_code)
    return target
