def test_vector_derivs(self):
        surrogate = KrigingSurrogate()

        x = array([[a, b] for a, b in
                   itertools.product(linspace(0, 1, 10), repeat=2)])
        y = array([[a+b, b-a] for a, b in x])

        surrogate.train(x, y)
        jac = surrogate.linearize(array([[0.5, 0.5]]))
        assert_rel_error(self, jac, array([[1, 1], [1, -1]]), 1e-5)
dataset/ETHPy150Open OpenMDAO/OpenMDAO/openmdao/surrogate_models/test/test_kriging.py/TestKrigingSurrogate.test_vector_derivs/swapped operands of `-`