test_scan.py 文件源码

def test_eliminate_nonseqs(self):
        W = tensor.scalar('W')
        sh = theano.shared(asarrayX(2.))
        x1 = tensor.vector('x1')
        x2 = tensor.scalar('x2')

        def rec_fn(*args):
            w = args[-1]
            return [(w + 1.,  # mitsot
                     w + 2.,  # sitsot
                     w + 3.),  # nitsot
                    {sh: w + 4.}]  # shared

        [X1, X2, X3], updates = theano.scan(
            rec_fn,
            [],
            [dict(initial=x1, taps=[-1, -3]), x2, None],
            W,
            n_steps=5,
            truncate_gradient=-1,
            go_backwards=False)
        f = theano.function([W, x1, x2], [X1, X2, X3],
                            updates=updates,
                            mode=theano.Mode(linker='py'),
                            allow_input_downcast=True)
        rng = numpy.random.RandomState(utt.fetch_seed())
        v_w = asarrayX(rng.uniform())
        outs = f(v_w, [0, 0, 0], 0)
        utt.assert_allclose(outs[0], v_w + 1)
        utt.assert_allclose(outs[1], v_w + 2)
        utt.assert_allclose(outs[2], v_w + 3)
        utt.assert_allclose(sh.get_value(), v_w + 4)