test_scan.py 文件源码

def test_compute_test_value_grad_cast():
    # Test for test values when variables have to be casted
    # Reported by Daniel Renshaw at
    # https://groups.google.com/d/topic/theano-users/o4jK9xDe5WI/discussion
    floatX = theano.config.floatX
    backup = theano.config.compute_test_value
    theano.config.compute_test_value = 'raise'
    try:
        h = tensor.matrix('h')
        h.tag.test_value = numpy.array([[1, 2, 3, 4], [5, 6, 7, 8]],
                                       dtype=floatX)

        w = theano.shared(numpy.random.randn(4, 3).astype(floatX), name='w')

        outputs, _ = theano.scan(lambda i, h, w: (theano.dot(h[i], w), i),
                                 outputs_info=[None, 0], non_sequences=[h, w],
                                 n_steps=3)

        theano.grad(outputs[0].sum(), w)
    finally:
        theano.config.compute_test_value = backup