Example #1
0
    def test_lookup_weighting(self):
        graph = tf.Graph()
        with graph.as_default():
            with tf.Session(graph=graph) as session:

                mem = Memory(4, 5, 2, 2)
                initial_mem = np.random.uniform(0, 1,
                                                (2, 4, 5)).astype(np.float32)
                keys = np.random.uniform(0, 1, (2, 5, 2)).astype(np.float32)
                strengths = np.random.uniform(0, 1, (2, 2)).astype(np.float32)

                norm_mem = initial_mem / np.sqrt(
                    np.sum(initial_mem**2, axis=2, keepdims=True))
                norm_keys = keys / np.sqrt(
                    np.sum(keys**2, axis=1, keepdims=True))
                sim = np.matmul(norm_mem, norm_keys)
                sim = sim * strengths[:, np.newaxis, :]
                predicted_wieghts = np.exp(sim) / np.sum(
                    np.exp(sim), axis=1, keepdims=True)

                mem.memory_matrix = tf.convert_to_tensor(initial_mem)
                op = mem.get_lookup_weighting(keys, strengths)
                c = session.run(op)

                self.assertEqual(c.shape, (2, 4, 2))
                self.assertTrue(np.allclose(c, predicted_wieghts))
Example #2
0
    def test_update_memory(self):
        graph = tf.Graph()
        with graph.as_default():
            with tf.Session(graph=graph) as session:

                mem = Memory(4, 5, 2, 2)
                write_weighting = random_softmax((2, 4), axis=1)
                write_vector = np.random.uniform(0, 1,
                                                 (2, 5)).astype(np.float32)
                erase_vector = np.random.uniform(0, 1,
                                                 (2, 5)).astype(np.float32)
                memory_matrix = np.random.uniform(-1, 1,
                                                  (2, 4, 5)).astype(np.float32)

                ww = write_weighting[:, :, np.newaxis]
                v, e = write_vector[:,
                                    np.newaxis, :], erase_vector[:,
                                                                 np.newaxis, :]
                predicted = memory_matrix * (1 - np.matmul(ww, e)) + np.matmul(
                    ww, v)

                mem.memory_matrix = tf.convert_to_tensor(memory_matrix)

                op = mem.update_memory(write_weighting, write_vector,
                                       erase_vector)
                M = session.run(op)
                #updated_memory = session.run(mem.memory_matrix.value())

                self.assertEqual(M.shape, (2, 4, 5))
                self.assertTrue(np.allclose(M, predicted))