test_basic.py 文件源码

def test_grad_keep_type(self):
        """Tests that the theano grad method returns a list if it is passed a list
        and a single variable if it is passed a single variable.
        pylearn2 depends on theano behaving this way. This functionality has been
        added three times and erroneously removed twice. If you do anything that
        requires changing this test or making it fail you are almost certainly
        making a common mistake, NOT fixing something. """

        X = tensor.matrix()
        y = X.sum()

        G = tensor.grad(y, [X])

        assert isinstance(G, list)

        G = tensor.grad(y, X)

        assert not isinstance(G, list)