test_gradient.py 文件源码

def test_grad(self):
        T = theano.tensor
        a = np.asarray(self.rng.randn(5, 5),
                       dtype=config.floatX)

        x = T.matrix('x')

        expressions_gradients = [
            (x * gradient.consider_constant(x), x),
            (x * gradient.consider_constant(T.exp(x)), T.exp(x)),
            (gradient.consider_constant(x), T.constant(0.)),
            (x**2 * gradient.consider_constant(x), 2 * x**2),
        ]

        for expr, expr_grad in expressions_gradients:
            g = gradient.grad(expr.sum(), x)
            # gradient according to theano
            f = theano.function([x], g, on_unused_input='ignore')
            # desired gradient
            f2 = theano.function([x], expr_grad, on_unused_input='ignore')

            assert np.allclose(f(a), f2(a))