call:

    >>> a = np.arange(6).reshape(2, 3)
    >>> a
    array([[0, 1, 2],
           [3, 4, 5]])
    >>> np.trapz(a, axis=0)
    array([1.5, 2.5, 3.5])
    >>> np.trapz(a, axis=1)
    array([2.,  8.])
    Nrq