def test_high_dim_attention(self, q_dims, v_dims, mask_dims, attention_axes): """Test with a mask tensor.""" test_layer = talking_heads_attention.TalkingHeadsAttention( num_heads=12, key_dim=2, attention_axes=attention_axes) batch_size, hidden_size = 3, 8 # Generate data for the input (non-mask) tensors. query_shape = [batch_size] + q_dims + [hidden_size] value_shape = [batch_size] + v_dims + [hidden_size] mask_shape = [batch_size] + mask_dims query = 10 * np.random.random_sample(query_shape) value = 10 * np.random.random_sample(value_shape) # Invoke the data with a random set of mask data. This should mask at least # one element. mask_data = np.random.randint(2, size=mask_shape).astype("bool") output = test_layer(query=query, value=value, attention_mask=mask_data) # Invoke the same data, but with a null mask (where no elements are masked). null_mask_data = np.ones(mask_shape) unmasked_output = test_layer(query=query, value=value, attention_mask=null_mask_data) # Because one data is masked and one is not, the outputs should not be the # same. self.assertNotAllClose(output, unmasked_output)
def test_masked_attention(self): """Test with a mask tensor.""" test_layer = talking_heads_attention.TalkingHeadsAttention(num_heads=2, head_size=2) # Create a 3-dimensional input (the first dimension is implicit). from_tensor = tf.keras.Input(shape=(4, 8)) to_tensor = tf.keras.Input(shape=(2, 8)) mask_tensor = tf.keras.Input(shape=(4, 2)) output = test_layer([from_tensor, to_tensor, mask_tensor]) # Create a model containing the test layer. model = tf.keras.Model([from_tensor, to_tensor, mask_tensor], output) # Generate data for the input (non-mask) tensors. from_data = 10 * np.random.random_sample((3, 4, 8)) to_data = 10 * np.random.random_sample((3, 2, 8)) # Invoke the data with a random set of mask data. This should mask at least # one element. mask_data = np.random.randint(2, size=(3, 4, 2)) masked_output_data = model.predict([from_data, to_data, mask_data]) # Invoke the same data, but with a null mask (where no elements are masked). null_mask_data = np.ones((3, 4, 2)) unmasked_output_data = model.predict( [from_data, to_data, null_mask_data]) # Because one data is masked and one is not, the outputs should not be the # same. self.assertNotAllClose(masked_output_data, unmasked_output_data)
def test_non_masked_self_attention(self): """Test with one input (self-attenntion) and no mask tensor.""" test_layer = talking_heads_attention.TalkingHeadsAttention( num_heads=12, key_dim=64) # Create a 3-dimensional input (the first dimension is implicit). query = tf.keras.Input(shape=(40, 80)) output = test_layer(query=query, value=query) self.assertEqual(output.shape.as_list(), [None, 40, 80])
def test_non_masked_self_attention(self): """Test with one input (self-attenntion) and no mask tensor.""" test_layer = talking_heads_attention.TalkingHeadsAttention( num_heads=12, head_size=64) # Create a 3-dimensional input (the first dimension is implicit). from_tensor = tf.keras.Input(shape=(40, 80)) output = test_layer([from_tensor, from_tensor]) self.assertEqual(output.shape.as_list(), [None, 40, 12, 64])
def test_attention_scores(self): """Test attention outputs with coefficients.""" test_layer = talking_heads_attention.TalkingHeadsAttention( num_heads=12, key_size=64, return_attention_scores=True) # Create a 3-dimensional input (the first dimension is implicit). query = tf.keras.Input(shape=(40, 80)) output, coef = test_layer(query=query, value=query) self.assertEqual(output.shape.as_list(), [None, 40, 80]) self.assertEqual(coef.shape.as_list(), [None, 12, 40, 40])
def test_non_masked_attention(self): """Test that the attention layer can be created without a mask tensor.""" test_layer = talking_heads_attention.TalkingHeadsAttention( num_heads=12, key_size=64) # Create a 3-dimensional input (the first dimension is implicit). from_tensor = tf.keras.Input(shape=(40, 80)) to_tensor = tf.keras.Input(shape=(20, 80)) output = test_layer([from_tensor, to_tensor]) self.assertEqual(output.shape.as_list(), [None, 40, 80])
def test_masked_attention(self, use_bias): """Test with a mask tensor.""" test_layer = talking_heads_attention.TalkingHeadsAttention( num_heads=12, key_dim=2, use_bias=use_bias) # Create a 3-dimensional input (the first dimension is implicit). batch_size = 3 query = tf.keras.Input(shape=(4, 8)) value = tf.keras.Input(shape=(2, 8)) mask_tensor = tf.keras.Input(shape=(4, 2)) output = test_layer(query=query, value=value, attention_mask=mask_tensor) # Create a model containing the test layer. model = tf.keras.Model([query, value, mask_tensor], output) # Generate data for the input (non-mask) tensors. from_data = 10 * np.random.random_sample((batch_size, 4, 8)) to_data = 10 * np.random.random_sample((batch_size, 2, 8)) # Invoke the data with a random set of mask data. This should mask at least # one element. mask_data = np.random.randint(2, size=(batch_size, 4, 2)) masked_output_data = model.predict([from_data, to_data, mask_data]) # Invoke the same data, but with a null mask (where no elements are masked). null_mask_data = np.ones((batch_size, 4, 2)) unmasked_output_data = model.predict( [from_data, to_data, null_mask_data]) # Because one data is masked and one is not, the outputs should not be the # same. self.assertNotAllClose(masked_output_data, unmasked_output_data) # Tests the layer with three inputs: Q, K, V. key = tf.keras.Input(shape=(2, 8)) output = test_layer(query=query, value=value, key=key, attention_mask=mask_tensor) model = tf.keras.Model([query, value, key, mask_tensor], output) masked_output_data = model.predict( [from_data, to_data, to_data, mask_data]) unmasked_output_data = model.predict( [from_data, to_data, to_data, null_mask_data]) # Because one data is masked and one is not, the outputs should not be the # same. self.assertNotAllClose(masked_output_data, unmasked_output_data) if use_bias: self.assertLen(test_layer._query_dense.trainable_variables, 2) self.assertLen(test_layer._output_dense.trainable_variables, 2) else: self.assertLen(test_layer._query_dense.trainable_variables, 1) self.assertLen(test_layer._output_dense.trainable_variables, 1)
def test_initializer(self): """Test with a specified initializer.""" test_layer = talking_heads_attention.TalkingHeadsAttention( num_heads=12, key_dim=64, kernel_initializer=tf.keras.initializers.TruncatedNormal(stddev=0.02)) # Create a 3-dimensional input (the first dimension is implicit). query = tf.keras.Input(shape=(40, 80)) output = test_layer(query=query, value=query) self.assertEqual(output.shape.as_list(), [None, 40, 80])
def test_non_masked_attention(self, value_dim, output_shape, output_dims): """Test that the attention layer can be created without a mask tensor.""" test_layer = talking_heads_attention.TalkingHeadsAttention( num_heads=12, key_dim=64, value_dim=value_dim, output_shape=output_shape) # Create a 3-dimensional input (the first dimension is implicit). query = tf.keras.Input(shape=(40, 80)) value = tf.keras.Input(shape=(20, 80)) output = test_layer(query=query, value=value) self.assertEqual(output.shape.as_list(), [None] + output_dims)