Function test

recipes/Python/580610_Auto_differentiation/recipe-580610.py:300–310

(x_array, *testcases)

        return (y1 - y0) / (2.0 * eps)

    def test(x_array, *testcases):
        for f in testcases:
            print(f.__name__.center(40))
            print('-' * 40)
            for x in map(Var, x_array):
                y = f(x)
                actual = d(y)
                expected = numeric_derivative(f, x, 2**-16)
                print('%7.3f  %12.4f  %12.4f' % (x, actual, expected))
                assert math.isclose(expected, actual, rel_tol=1e-5)
            print('')

    def test_pow_const_base(x):
        return 3.1 ** (2.3 * x + 0.4)