def test_loss_3d_input(self):
"""Test overall loss with a 3-dimensional input, from a masked LM."""
vocab_size = 100
sequence_length = 32
hidden_size = 64
num_predictions = 21
model = self.create_lm_model(vocab_size=vocab_size,
sequence_length=sequence_length,
hidden_size=hidden_size,
num_predictions=num_predictions)
# Get the output of the masked LM.
batch_size = 3
lm_input_data = 10 * np.random.random_sample(
(batch_size, sequence_length, hidden_size))
masked_position_data = np.random.randint(2,
size=(batch_size,
num_predictions))
output_data = model.predict([lm_input_data, masked_position_data])
# Calculate loss.
labels = np.random.randint(vocab_size,
size=(batch_size, num_predictions))
weights = np.random.randint(2, size=(batch_size, num_predictions))
per_example_loss_data = weighted_sparse_categorical_crossentropy.loss(
predictions=output_data, labels=labels, weights=weights)
# Total loss data should have one value, and that value shouldn't be zero
# in this case (as we're using random data).
expected_shape = [] # Scalar
self.assertEqual(expected_shape, per_example_loss_data.shape.as_list())
self.assertNotAllClose(tf.zeros_like(per_example_loss_data),
per_example_loss_data)
def test_loss_weights_3d_input(self):
"""Test masked loss with a 3-dimensional input, from a masked LM."""
vocab_size = 100
sequence_length = 32
hidden_size = 64
num_predictions = 21
model = self.create_lm_model(vocab_size=vocab_size,
sequence_length=sequence_length,
hidden_size=hidden_size,
num_predictions=num_predictions)
# Get the output of the masked LM.
batch_size = 3
lm_input_data = 10 * np.random.random_sample(
(batch_size, sequence_length, hidden_size))
masked_position_data = np.random.randint(2,
size=(batch_size,
num_predictions))
output_data = model.predict([lm_input_data, masked_position_data])
# Calculate a fully masked weight tensor. This should give a loss of zero.
labels = np.random.randint(vocab_size,
size=(batch_size, num_predictions))
null_weights = np.zeros((batch_size, num_predictions))
weighted_loss_data = weighted_sparse_categorical_crossentropy.loss(
predictions=output_data, labels=labels, weights=null_weights)
# Because the tensor is fully masked, the loss should be 0.
self.assertAllClose(0, weighted_loss_data)
def test_legacy_lm_loss_compatibility(self):
"""Test to validate computational correctness during refactors."""
# This is the empirical output of a masked LM with the following parameters:
# batch_size = 3
# vocab_size = 5
# sequence_length = 4
# num_predictions = 2
output_data = np.array(
[[[-2.5286622, -1.0963473, -1.4925185, -2.4451098, -1.2923571],
[-2.7117882, -1.1205841, -4.02187, -0.9966936, -1.5119683]],
[[-2.5379114, -0.82479054, -2.287932, -1.3747153, -2.053741],
[-2.5379114, -0.82479054, -2.287932, -1.3747153, -2.053741]],
[[-2.7760355, -1.8219438, -3.0924666, -1.0779881, -0.9407509],
[-2.7760355, -1.8219438, -3.0924666, -1.0779881, -0.9407509]]])
labels = np.array([[4, 0], [2, 2], [2, 1]])
# Validate that overall loss calculations are the same.
weights = np.array([[1, 0], [0, 0], [0, 0]])
loss_data = weighted_sparse_categorical_crossentropy.loss(
predictions=output_data,
labels=labels,
weights=weights,
from_logits=True)
expected_loss_data = 1.2923441
self.assertAllClose(expected_loss_data, loss_data, rtol=1e-3)
def test_mismatched_predictions_and_labels_ranks_squeezes(self):
"""Test that the loss asserts when rank(predictions)-1 != rank(labels)."""
batch_size = 3
output_data = np.random.random_sample((batch_size, 10))
labels = np.random.randint(10, size=(batch_size, 1))
# All that this test tests is that the squeeze is successful.
_ = weighted_sparse_categorical_crossentropy.loss(
predictions=output_data, labels=labels)
def test_mismatched_weights_and_labels_ranks_fail(self):
"""Test that the loss asserts when rank(predictions) != rank(labels)."""
batch_size = 3
output_data = np.random.random_sample((batch_size, 10, 15))
labels = np.random.randint(10, size=(batch_size, 10))
weights = np.random.randint(2, size=(batch_size))
with self.assertRaisesRegex(RuntimeError, ".*of the same rank.*"):
_ = weighted_sparse_categorical_crossentropy.loss(
predictions=output_data, labels=labels, weights=weights)
def test_tf_tensor_inputs(self):
"""Test that tf.Tensors can be used as inputs to the loss function."""
batch_size = 3
output_data = tf.convert_to_tensor(
np.random.random_sample((batch_size, 10, 15)))
labels = tf.convert_to_tensor(np.random.randint(10, size=(batch_size, 10)))
weights = tf.convert_to_tensor(np.random.randint(2, size=(batch_size, 10)))
# We're not trying to validate numerical correctness, just ensure that
# we can in fact pass tensors to these functions without causing runtime
# errors from the shape checking code.
_ = weighted_sparse_categorical_crossentropy.loss(
predictions=output_data, labels=labels, weights=weights)
def test_legacy_classification_loss_compatibility(self):
"""Test to validate computational correctness during refactors."""
# This is the empirical output of a classifier with the following params:
# batch_size = 2
# num_classes = 3
output_data = np.array([[-1.6094601e-03, -1.0966038e+01, -6.4434357e+00],
[-1.6975292e-03, -6.4009643e+00, -1.0226612e+01]])
labels = np.array([2, 1])
# Validate that overall loss calculations are the same.
weights = None
loss_data = weighted_sparse_categorical_crossentropy.loss(
predictions=output_data,
labels=labels,
weights=weights,
from_logits=True)
expected_loss_data = 6.4222
self.assertAllClose(expected_loss_data, loss_data, rtol=1e-3)
def test_loss_weights_2d_input(self):
"""Test masked loss with a 2-d input, from a classifier."""
input_width = 512
num_classes = 10
model = self.create_classification_model(input_width, num_classes)
# Invoke the network as part of a Model.
batch_size = 3
input_data = 10 * np.random.random_sample((batch_size, input_width))
output_data = model.predict(input_data)
# Calculate a fully masked weight tensor. This should give a loss of zero.
labels = np.random.randint(num_classes, size=(batch_size))
null_weights = np.zeros((batch_size))
weighted_loss_data = weighted_sparse_categorical_crossentropy.loss(
predictions=output_data, labels=labels, weights=null_weights)
# Because the tensor is fully masked, the loss should be 0.
self.assertAllClose(0, weighted_loss_data)
def test_loss_2d_input(self):
"""Test overall loss with a 2-d input, from a classifier."""
input_width = 512
num_classes = 10
model = self.create_classification_model(input_width, num_classes)
# Invoke the network as part of a Model.
batch_size = 3
input_data = 10 * np.random.random_sample((batch_size, input_width))
output_data = model.predict(input_data)
# Calculate per example loss.
labels = np.random.randint(num_classes, size=(batch_size))
loss_data = weighted_sparse_categorical_crossentropy.loss(
predictions=output_data, labels=labels)
# Loss data should have one value only, and that value shouldn't be zero in
# this case (as we're using random data).
self.assertNotAllClose(0, loss_data)
