test_subtensor.py 文件源码

def test_slice_canonical_form_2(self):
        start = tensor.iscalar('b')
        step = tensor.iscalar('s')
        length = tensor.iscalar('l')
        cnf = get_canonical_form_slice(slice(start, None, step), length)
        f = self.function([start, step, length], [
            tensor.as_tensor_variable(cnf[0].start),
            tensor.as_tensor_variable(cnf[0].stop),
            tensor.as_tensor_variable(cnf[0].step),
            tensor.as_tensor_variable(cnf[1])], N=0, op=self.ops)

        length = 5
        a = numpy.arange(length)
        for start in [-8, -5, -4, -1, 0, 1, 4, 5, 8]:
            for step in [-6, -3, -1, 2, 5]:
                out = f(start, step, length)
                t_out = a[out[0]:out[1]:out[2]][::out[3]]
                v_out = a[start:None:step]
                assert numpy.all(t_out == v_out)
                assert numpy.all(t_out.shape == v_out.shape)