def fun(self, x):
        e = x[:-1]**2 - x[1:]**3
        return np.hstack((0, 3 * e)) + np.hstack((2 * e, 0))
dataset/ETHPy150Open scipy/scipy/scipy/optimize/tests/test__numdiff.py/TestApproxDerivativeSparse.fun/swapped operands of `-`