A rank-1 linear function with zero columns and rows (lmder test #3)

def _lmder1_linear_r1zcr(n, m, factor, target_fnorm1, target_fnorm2, target_params):
    """A rank-1 linear function with zero columns and rows (lmder test #3)"""

    def func(params, vec):
        s = 0
        for j in range(1, n - 1):
            s += (j + 1) * params[j]
        for i in range(m):
            vec[i] = i * s - 1
        vec[m-1] = -1

    def jac(params, jac):
        jac.fill(0)

        for i in range(1, n - 1):
            for j in range(1, m - 1):
                jac[i,j] = j * (i + 1)

    guess = np.ones(n) * factor

    #_lmder1_test(m, func, jac, guess)
    _lmder1_driver(m, func, jac, guess,
                   target_fnorm1, target_fnorm2, None)