Esempio n. 1
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 def sample_fn(x):
     return sampler_py.categorical_sample(logits=x)
Esempio n. 2
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    def testStepWithInferenceHelperCategorical(self):
        batch_size = 5
        vocabulary_size = 7
        cell_depth = vocabulary_size
        start_token = 0
        end_token = 6

        start_inputs = tf.one_hot(
            np.ones(batch_size, dtype=np.int32) * start_token, vocabulary_size)

        # The sample function samples categorically from the logits.
        sample_fn = lambda x: sampler_py.categorical_sample(logits=x)
        # The next inputs are a one-hot encoding of the sampled labels.
        next_inputs_fn = (
            lambda x: tf.one_hot(x, vocabulary_size, dtype=tf.float32))
        end_fn = lambda sample_ids: tf.equal(sample_ids, end_token)

        with self.cached_session(use_gpu=True):
            cell = tf.keras.layers.LSTMCell(vocabulary_size)
            sampler = sampler_py.InferenceSampler(
                sample_fn,
                sample_shape=(),
                sample_dtype=tf.int32,
                end_fn=end_fn,
                next_inputs_fn=next_inputs_fn)
            initial_state = cell.get_initial_state(batch_size=batch_size,
                                                   dtype=tf.float32)
            my_decoder = basic_decoder.BasicDecoder(cell=cell, sampler=sampler)
            (first_finished, first_inputs,
             first_state) = my_decoder.initialize(start_inputs,
                                                  initial_state=initial_state)

            output_size = my_decoder.output_size
            output_dtype = my_decoder.output_dtype
            self.assertEqual(
                basic_decoder.BasicDecoderOutput(cell_depth,
                                                 tf.TensorShape([])),
                output_size)
            self.assertEqual(
                basic_decoder.BasicDecoderOutput(tf.float32, tf.int32),
                output_dtype)

            (step_outputs, step_state, step_next_inputs,
             step_finished) = my_decoder.step(tf.constant(0), first_inputs,
                                              first_state)
            batch_size_t = my_decoder.batch_size

            self.assertLen(first_state, 2)
            self.assertLen(step_state, 2)
            self.assertTrue(
                isinstance(step_outputs, basic_decoder.BasicDecoderOutput))
            self.assertEqual((batch_size, cell_depth),
                             step_outputs[0].get_shape())
            self.assertEqual((batch_size, ), step_outputs[1].get_shape())
            self.assertEqual((batch_size, cell_depth),
                             first_state[0].get_shape())
            self.assertEqual((batch_size, cell_depth),
                             first_state[1].get_shape())
            self.assertEqual((batch_size, cell_depth),
                             step_state[0].get_shape())
            self.assertEqual((batch_size, cell_depth),
                             step_state[1].get_shape())

            self.evaluate(tf.compat.v1.global_variables_initializer())
            eval_result = self.evaluate({
                "batch_size": batch_size_t,
                "first_finished": first_finished,
                "first_inputs": first_inputs,
                "first_state": first_state,
                "step_outputs": step_outputs,
                "step_state": step_state,
                "step_next_inputs": step_next_inputs,
                "step_finished": step_finished
            })

            sample_ids = eval_result["step_outputs"].sample_id
            self.assertEqual(output_dtype.sample_id, sample_ids.dtype)
            expected_step_finished = (sample_ids == end_token)
            expected_step_next_inputs = np.zeros((batch_size, vocabulary_size))
            expected_step_next_inputs[np.arange(batch_size), sample_ids] = 1.0
            self.assertAllEqual(expected_step_finished,
                                eval_result["step_finished"])
            self.assertAllEqual(expected_step_next_inputs,
                                eval_result["step_next_inputs"])