def test_get_text_field_mask_returns_mask_key(self):
text_field_tensors = {
"tokens": torch.LongTensor([[3, 4, 5, 0, 0], [1, 2, 0, 0, 0]]),
"mask": torch.LongTensor([[0, 0, 1]])
}
assert_almost_equal(
util.get_text_field_mask(text_field_tensors).numpy(), [[0, 0, 1]])
def _get_initial_rnn_state(self, sentence: Dict[str, torch.LongTensor]):
embedded_input = self._sentence_embedder(sentence)
# (batch_size, sentence_length)
sentence_mask = util.get_text_field_mask(sentence).float()
batch_size = embedded_input.size(0)
# (batch_size, sentence_length, encoder_output_dim)
encoder_outputs = self._dropout(
self._encoder(embedded_input, sentence_mask))
final_encoder_output = util.get_final_encoder_states(
encoder_outputs, sentence_mask, self._encoder.is_bidirectional())
memory_cell = encoder_outputs.new_zeros(batch_size,
self._encoder.get_output_dim())
attended_sentence = self._decoder_step.attend_on_sentence(
final_encoder_output, encoder_outputs, sentence_mask)
encoder_outputs_list = [encoder_outputs[i] for i in range(batch_size)]
sentence_mask_list = [sentence_mask[i] for i in range(batch_size)]
initial_rnn_state = []
for i in range(batch_size):
initial_rnn_state.append(
RnnState(final_encoder_output[i], memory_cell[i],
self._first_action_embedding, attended_sentence[i],
encoder_outputs_list, sentence_mask_list))
return initial_rnn_state
def test_get_text_field_mask_returns_a_correct_mask_character_only_input(
self):
text_field_tensors = {
"token_characters":
torch.LongTensor([[[1, 2, 3], [3, 0, 1], [2, 1, 0], [0, 0, 0]],
[[5, 5, 5], [4, 6, 0], [0, 0, 0], [0, 0, 0]]])
}
assert_almost_equal(
util.get_text_field_mask(text_field_tensors).numpy(),
[[1, 1, 1, 0], [1, 1, 0, 0]])
def test_get_text_field_mask_returns_a_correct_mask_list_field(self):
text_field_tensors = {
"list_tokens":
torch.LongTensor([[[1, 2], [3, 0], [2, 0], [0, 0], [0, 0]],
[[5, 0], [4, 6], [0, 0], [0, 0], [0, 0]]])
}
actual_mask = util.get_text_field_mask(text_field_tensors,
num_wrapping_dims=1).numpy()
expected_mask = (text_field_tensors['list_tokens'].numpy() >
0).astype('int32')
assert_almost_equal(actual_mask, expected_mask)
def forward(
self, # type: ignore
words: Dict[str, torch.LongTensor],
pos_tags: torch.LongTensor,
metadata: List[Dict[str, Any]],
head_tags: torch.LongTensor = None,
head_indices: torch.LongTensor = None) -> Dict[str, torch.Tensor]:
# pylint: disable=arguments-differ
"""
Parameters
----------
words : Dict[str, torch.LongTensor], required
The output of ``TextField.as_array()``, which should typically be passed directly to a
``TextFieldEmbedder``. This output is a dictionary mapping keys to ``TokenIndexer``
tensors. At its most basic, using a ``SingleIdTokenIndexer`` this is: ``{"tokens":
Tensor(batch_size, sequence_length)}``. This dictionary will have the same keys as were used
for the ``TokenIndexers`` when you created the ``TextField`` representing your
sequence. The dictionary is designed to be passed directly to a ``TextFieldEmbedder``,
which knows how to combine different word representations into a single vector per
token in your input.
pos_tags : ``torch.LongTensor``, required.
The output of a ``SequenceLabelField`` containing POS tags.
POS tags are required regardless of whether they are used in the model,
because they are used to filter the evaluation metric to only consider
heads of words which are not punctuation.
head_tags : torch.LongTensor, optional (default = None)
A torch tensor representing the sequence of integer gold class labels for the arcs
in the dependency parse. Has shape ``(batch_size, sequence_length)``.
head_indices : torch.LongTensor, optional (default = None)
A torch tensor representing the sequence of integer indices denoting the parent of every
word in the dependency parse. Has shape ``(batch_size, sequence_length)``.
Returns
-------
An output dictionary consisting of:
loss : ``torch.FloatTensor``, optional
A scalar loss to be optimised.
arc_loss : ``torch.FloatTensor``
The loss contribution from the unlabeled arcs.
loss : ``torch.FloatTensor``, optional
The loss contribution from predicting the dependency
tags for the gold arcs.
heads : ``torch.FloatTensor``
The predicted head indices for each word. A tensor
of shape (batch_size, sequence_length).
head_types : ``torch.FloatTensor``
The predicted head types for each arc. A tensor
of shape (batch_size, sequence_length).
mask : ``torch.LongTensor``
A mask denoting the padded elements in the batch.
"""
embedded_text_input = self.text_field_embedder(words)
if pos_tags is not None and self._pos_tag_embedding is not None:
embedded_pos_tags = self._pos_tag_embedding(pos_tags)
embedded_text_input = torch.cat(
[embedded_text_input, embedded_pos_tags], -1)
elif self._pos_tag_embedding is not None:
raise ConfigurationError(
"Model uses a POS embedding, but no POS tags were passed.")
mask = get_text_field_mask(words)
embedded_text_input = self._input_dropout(embedded_text_input)
encoded_text = self.encoder(embedded_text_input, mask)
batch_size, _, encoding_dim = encoded_text.size()
head_sentinel = self._head_sentinel.expand(batch_size, 1, encoding_dim)
# Concatenate the head sentinel onto the sentence representation.
encoded_text = torch.cat([head_sentinel, encoded_text], 1)
mask = torch.cat([mask.new_ones(batch_size, 1), mask], 1)
if head_indices is not None:
head_indices = torch.cat(
[head_indices.new_zeros(batch_size, 1), head_indices], 1)
if head_tags is not None:
head_tags = torch.cat(
[head_tags.new_zeros(batch_size, 1), head_tags], 1)
float_mask = mask.float()
encoded_text = self._dropout(encoded_text)
# shape (batch_size, sequence_length, arc_representation_dim)
head_arc_representation = self._dropout(
self.head_arc_feedforward(encoded_text))
child_arc_representation = self._dropout(
self.child_arc_feedforward(encoded_text))
# shape (batch_size, sequence_length, tag_representation_dim)
head_tag_representation = self._dropout(
self.head_tag_feedforward(encoded_text))
child_tag_representation = self._dropout(
self.child_tag_feedforward(encoded_text))
# shape (batch_size, sequence_length, sequence_length)
attended_arcs = self.arc_attention(head_arc_representation,
child_arc_representation)
minus_inf = -1e8
minus_mask = (1 - float_mask) * minus_inf
attended_arcs = attended_arcs + minus_mask.unsqueeze(
2) + minus_mask.unsqueeze(1)
if self.training or not self.use_mst_decoding_for_validation:
predicted_heads, predicted_head_tags = self._greedy_decode(
head_tag_representation, child_tag_representation,
attended_arcs, mask)
else:
predicted_heads, predicted_head_tags = self._mst_decode(
head_tag_representation, child_tag_representation,
attended_arcs, mask)
if head_indices is not None and head_tags is not None:
arc_nll, tag_nll = self._construct_loss(
head_tag_representation=head_tag_representation,
child_tag_representation=child_tag_representation,
attended_arcs=attended_arcs,
head_indices=head_indices,
head_tags=head_tags,
mask=mask)
loss = arc_nll + tag_nll
evaluation_mask = self._get_mask_for_eval(mask[:, 1:], pos_tags)
# We calculate attatchment scores for the whole sentence
# but excluding the symbolic ROOT token at the start,
# which is why we start from the second element in the sequence.
self._attachment_scores(predicted_heads[:, 1:],
predicted_head_tags[:,
1:], head_indices[:,
1:],
head_tags[:, 1:], evaluation_mask)
else:
arc_nll, tag_nll = self._construct_loss(
head_tag_representation=head_tag_representation,
child_tag_representation=child_tag_representation,
attended_arcs=attended_arcs,
head_indices=predicted_heads.long(),
head_tags=predicted_head_tags.long(),
mask=mask)
loss = arc_nll + tag_nll
output_dict = {
"heads": predicted_heads,
"head_tags": predicted_head_tags,
"arc_loss": arc_nll,
"tag_loss": tag_nll,
"loss": loss,
"mask": mask,
"words": [meta["words"] for meta in metadata],
"pos": [meta["pos"] for meta in metadata]
}
return output_dict
def forward(
self, # type: ignore
tokens: Dict[str, torch.LongTensor],
verb_indicator: torch.LongTensor,
tags: torch.LongTensor = None,
metadata: List[Dict[str, Any]] = None) -> Dict[str, torch.Tensor]:
# pylint: disable=arguments-differ
"""
Parameters
----------
tokens : Dict[str, torch.LongTensor], required
The output of ``TextField.as_array()``, which should typically be passed directly to a
``TextFieldEmbedder``. This output is a dictionary mapping keys to ``TokenIndexer``
tensors. At its most basic, using a ``SingleIdTokenIndexer`` this is: ``{"tokens":
Tensor(batch_size, num_tokens)}``. This dictionary will have the same keys as were used
for the ``TokenIndexers`` when you created the ``TextField`` representing your
sequence. The dictionary is designed to be passed directly to a ``TextFieldEmbedder``,
which knows how to combine different word representations into a single vector per
token in your input.
verb_indicator: torch.LongTensor, required.
An integer ``SequenceFeatureField`` representation of the position of the verb
in the sentence. This should have shape (batch_size, num_tokens) and importantly, can be
all zeros, in the case that the sentence has no verbal predicate.
tags : torch.LongTensor, optional (default = None)
A torch tensor representing the sequence of integer gold class labels
of shape ``(batch_size, num_tokens)``
metadata : ``List[Dict[str, Any]]``, optional, (default = None)
metadata containg the original words in the sentence and the verb to compute the
frame for, under 'words' and 'verb' keys, respectively.
Returns
-------
An output dictionary consisting of:
logits : torch.FloatTensor
A tensor of shape ``(batch_size, num_tokens, tag_vocab_size)`` representing
unnormalised log probabilities of the tag classes.
class_probabilities : torch.FloatTensor
A tensor of shape ``(batch_size, num_tokens, tag_vocab_size)`` representing
a distribution of the tag classes per word.
loss : torch.FloatTensor, optional
A scalar loss to be optimised.
"""
embedded_text_input = self.embedding_dropout(
self.text_field_embedder(tokens))
mask = get_text_field_mask(tokens)
embedded_verb_indicator = self.binary_feature_embedding(
verb_indicator.long())
# Concatenate the verb feature onto the embedded text. This now
# has shape (batch_size, sequence_length, embedding_dim + binary_feature_dim).
embedded_text_with_verb_indicator = torch.cat(
[embedded_text_input, embedded_verb_indicator], -1)
batch_size, sequence_length, _ = embedded_text_with_verb_indicator.size(
)
encoded_text = self.encoder(embedded_text_with_verb_indicator, mask)
logits = self.tag_projection_layer(encoded_text)
reshaped_log_probs = logits.view(-1, self.num_classes)
class_probabilities = F.softmax(reshaped_log_probs, dim=-1).view(
[batch_size, sequence_length, self.num_classes])
output_dict = {
"logits": logits,
"class_probabilities": class_probabilities
}
if tags is not None:
loss = sequence_cross_entropy_with_logits(
logits, tags, mask, label_smoothing=self._label_smoothing)
self.span_metric(class_probabilities, tags, mask)
output_dict["loss"] = loss
# We need to retain the mask in the output dictionary
# so that we can crop the sequences to remove padding
# when we do viterbi inference in self.decode.
output_dict["mask"] = mask
words, verbs = zip(*[(x["words"], x["verb"]) for x in metadata])
if metadata is not None:
output_dict["words"] = list(words)
output_dict["verb"] = list(verbs)
return output_dict
def forward(
self, # type: ignore
tokens: Dict[str, torch.LongTensor],
tags: torch.LongTensor = None,
metadata: List[Dict[str, Any]] = None) -> Dict[str, torch.Tensor]:
# pylint: disable=arguments-differ
"""
Parameters
----------
tokens : Dict[str, torch.LongTensor], required
The output of ``TextField.as_array()``, which should typically be passed directly to a
``TextFieldEmbedder``. This output is a dictionary mapping keys to ``TokenIndexer``
tensors. At its most basic, using a ``SingleIdTokenIndexer`` this is: ``{"tokens":
Tensor(batch_size, num_tokens)}``. This dictionary will have the same keys as were used
for the ``TokenIndexers`` when you created the ``TextField`` representing your
sequence. The dictionary is designed to be passed directly to a ``TextFieldEmbedder``,
which knows how to combine different word representations into a single vector per
token in your input.
tags : torch.LongTensor, optional (default = None)
A torch tensor representing the sequence of integer gold class labels of shape
``(batch_size, num_tokens)``.
metadata : ``List[Dict[str, Any]]``, optional, (default = None)
metadata containg the original words in the sentence to be tagged under a 'words' key.
Returns
-------
An output dictionary consisting of:
logits : torch.FloatTensor
A tensor of shape ``(batch_size, num_tokens, tag_vocab_size)`` representing
unnormalised log probabilities of the tag classes.
class_probabilities : torch.FloatTensor
A tensor of shape ``(batch_size, num_tokens, tag_vocab_size)`` representing
a distribution of the tag classes per word.
loss : torch.FloatTensor, optional
A scalar loss to be optimised.
"""
embedded_text_input = self.text_field_embedder(tokens)
batch_size, sequence_length, _ = embedded_text_input.size()
mask = get_text_field_mask(tokens)
encoded_text = self.encoder(embedded_text_input, mask)
logits = self.tag_projection_layer(encoded_text)
reshaped_log_probs = logits.view(-1, self.num_classes)
class_probabilities = F.softmax(reshaped_log_probs, dim=-1).view(
[batch_size, sequence_length, self.num_classes])
output_dict = {
"logits": logits,
"class_probabilities": class_probabilities
}
if tags is not None:
loss = sequence_cross_entropy_with_logits(logits, tags, mask)
for metric in self.metrics.values():
metric(logits, tags, mask.float())
output_dict["loss"] = loss
if metadata is not None:
output_dict["words"] = [x["words"] for x in metadata]
return output_dict
def forward(
self, # type: ignore
premise: Dict[str, torch.LongTensor],
hypothesis: Dict[str, torch.LongTensor],
label: torch.LongTensor = None,
metadata: List[Dict[str, Any]] = None # pylint:disable=unused-argument
) -> Dict[str, torch.Tensor]:
# pylint: disable=arguments-differ
"""
Parameters
----------
premise : Dict[str, torch.LongTensor]
The premise from a ``TextField``
hypothesis : Dict[str, torch.LongTensor]
The hypothesis from a ``TextField``
label : torch.LongTensor, optional (default = None)
The label for the pair of the premise and the hypothesis
metadata : ``List[Dict[str, Any]]``, optional, (default = None)
Additional information about the pair
Returns
-------
An output dictionary consisting of:
logits : torch.FloatTensor
A tensor of shape ``(batch_size, num_labels)`` representing unnormalised log
probabilities of the entailment label.
loss : torch.FloatTensor, optional
A scalar loss to be optimised.
"""
mask_premise = util.get_text_field_mask(premise)
mask_hypothesis = util.get_text_field_mask(hypothesis)
# embedding and encoding of the premise
embedded_premise = self.dropout(self.text_field_embedder(premise))
encoded_premise1 = self.dropout(
self.encoder1(embedded_premise, mask_premise))
encoded_premise2 = self.dropout(
self.encoder2(encoded_premise1, mask_premise))
# embedding and encoding of the hypothesis
embedded_hypothesis = self.dropout(
self.text_field_embedder(hypothesis))
encoded_hypothesis1 = self.dropout(
self.encoder1(embedded_hypothesis, mask_hypothesis))
encoded_hypothesis2 = self.dropout(
self.encoder2(encoded_hypothesis1, mask_hypothesis))
matching_vector_premise: List[torch.Tensor] = []
matching_vector_hypothesis: List[torch.Tensor] = []
def add_matching_result(matcher, encoded_premise, encoded_hypothesis):
# utility function to get matching result and add to the result list
matching_result = matcher(encoded_premise, mask_premise,
encoded_hypothesis, mask_hypothesis)
matching_vector_premise.extend(matching_result[0])
matching_vector_hypothesis.extend(matching_result[1])
# calculate matching vectors from word embedding, first layer encoding, and second layer encoding
add_matching_result(self.matcher_word, embedded_premise,
embedded_hypothesis)
half_hidden_size_1 = self.encoder1.get_output_dim() // 2
add_matching_result(self.matcher_forward1,
encoded_premise1[:, :, :half_hidden_size_1],
encoded_hypothesis1[:, :, :half_hidden_size_1])
add_matching_result(self.matcher_backward1,
encoded_premise1[:, :, half_hidden_size_1:],
encoded_hypothesis1[:, :, half_hidden_size_1:])
half_hidden_size_2 = self.encoder2.get_output_dim() // 2
add_matching_result(self.matcher_forward2,
encoded_premise2[:, :, :half_hidden_size_2],
encoded_hypothesis2[:, :, :half_hidden_size_2])
add_matching_result(self.matcher_backward2,
encoded_premise2[:, :, half_hidden_size_2:],
encoded_hypothesis2[:, :, half_hidden_size_2:])
# concat the matching vectors
matching_vector_cat_premise = self.dropout(
torch.cat(matching_vector_premise, dim=2))
matching_vector_cat_hypothesis = self.dropout(
torch.cat(matching_vector_hypothesis, dim=2))
# aggregate the matching vectors
aggregated_premise = self.dropout(
self.aggregator(matching_vector_cat_premise, mask_premise))
aggregated_hypothesis = self.dropout(
self.aggregator(matching_vector_cat_hypothesis, mask_hypothesis))
# the final forward layer
logits = self.classifier_feedforward(
torch.cat([aggregated_premise, aggregated_hypothesis], dim=-1))
output_dict = {'logits': logits}
if label is not None:
loss = self.loss(logits, label)
for metric in self.metrics.values():
metric(logits, label)
output_dict["loss"] = loss
return output_dict
def forward(self, # type: ignore
tokens: Dict[str, torch.LongTensor],
label: torch.LongTensor = None) -> Dict[str, torch.Tensor]:
# pylint: disable=arguments-differ
"""
Parameters
----------
tokens : Dict[str, torch.LongTensor], required
The output of ``TextField.as_array()``.
label : torch.LongTensor, optional (default = None)
A variable representing the label for each instance in the batch.
Returns
-------
An output dictionary consisting of:
class_probabilities : torch.FloatTensor
A tensor of shape ``(batch_size, num_classes)`` representing a
distribution over the label classes for each instance.
loss : torch.FloatTensor, optional
A scalar loss to be optimised.
"""
text_mask = util.get_text_field_mask(tokens).float()
# Pop elmo tokens, since elmo embedder should not be present.
elmo_tokens = tokens.pop("elmo", None)
embedded_text = self._text_field_embedder(tokens)
# Add the "elmo" key back to "tokens" if not None, since the tests and the
# subsequent training epochs rely not being modified during forward()
if elmo_tokens is not None:
tokens["elmo"] = elmo_tokens
# Create ELMo embeddings if applicable
if self._elmo:
if elmo_tokens is not None:
elmo_representations = self._elmo(elmo_tokens)["elmo_representations"]
# Pop from the end is more performant with list
if self._use_integrator_output_elmo:
integrator_output_elmo = elmo_representations.pop()
if self._use_input_elmo:
input_elmo = elmo_representations.pop()
assert not elmo_representations
else:
raise ConfigurationError(
"Model was built to use Elmo, but input text is not tokenized for Elmo.")
if self._use_input_elmo:
embedded_text = torch.cat([embedded_text, input_elmo], dim=-1)
dropped_embedded_text = self._embedding_dropout(embedded_text)
pre_encoded_text = self._pre_encode_feedforward(dropped_embedded_text)
encoded_tokens = self._encoder(pre_encoded_text, text_mask)
# Compute biattention. This is a special case since the inputs are the same.
attention_logits = encoded_tokens.bmm(encoded_tokens.permute(0, 2, 1).contiguous())
attention_weights = util.last_dim_softmax(attention_logits, text_mask)
encoded_text = util.weighted_sum(encoded_tokens, attention_weights)
# Build the input to the integrator
integrator_input = torch.cat([encoded_tokens,
encoded_tokens - encoded_text,
encoded_tokens * encoded_text], 2)
integrated_encodings = self._integrator(integrator_input, text_mask)
# Concatenate ELMo representations to integrated_encodings if specified
if self._use_integrator_output_elmo:
integrated_encodings = torch.cat([integrated_encodings,
integrator_output_elmo], dim=-1)
# Simple Pooling layers
max_masked_integrated_encodings = util.replace_masked_values(
integrated_encodings, text_mask.unsqueeze(2), -1e7)
max_pool = torch.max(max_masked_integrated_encodings, 1)[0]
min_masked_integrated_encodings = util.replace_masked_values(
integrated_encodings, text_mask.unsqueeze(2), +1e7)
min_pool = torch.min(min_masked_integrated_encodings, 1)[0]
mean_pool = torch.sum(integrated_encodings, 1) / torch.sum(text_mask, 1, keepdim=True)
# Self-attentive pooling layer
# Run through linear projection. Shape: (batch_size, sequence length, 1)
# Then remove the last dimension to get the proper attention shape (batch_size, sequence length).
self_attentive_logits = self._self_attentive_pooling_projection(
integrated_encodings).squeeze(2)
self_weights = util.masked_softmax(self_attentive_logits, text_mask)
self_attentive_pool = util.weighted_sum(integrated_encodings, self_weights)
pooled_representations = torch.cat([max_pool, min_pool, mean_pool, self_attentive_pool], 1)
pooled_representations_dropped = self._integrator_dropout(pooled_representations)
logits = self._output_layer(pooled_representations_dropped)
class_probabilities = F.softmax(logits, dim=-1)
output_dict = {'logits': logits, 'class_probabilities': class_probabilities}
if label is not None:
loss = self.loss(logits, label)
for metric in self.metrics.values():
metric(logits, label)
output_dict["loss"] = loss
return output_dict
def forward(
self, # type: ignore
source_tokens: Dict[str, torch.LongTensor],
target_tokens: Dict[str, torch.LongTensor] = None
) -> Dict[str, torch.Tensor]:
# pylint: disable=arguments-differ
"""
Decoder logic for producing the entire target sequence.
Parameters
----------
source_tokens : Dict[str, torch.LongTensor]
The output of ``TextField.as_array()`` applied on the source ``TextField``. This will be
passed through a ``TextFieldEmbedder`` and then through an encoder.
target_tokens : Dict[str, torch.LongTensor], optional (default = None)
Output of ``Textfield.as_array()`` applied on target ``TextField``. We assume that the
target tokens are also represented as a ``TextField``.
"""
# (batch_size, input_sequence_length, encoder_output_dim)
embedded_input = self._source_embedder(source_tokens)
batch_size, _, _ = embedded_input.size()
source_mask = get_text_field_mask(source_tokens)
encoder_outputs = self._encoder(embedded_input, source_mask)
final_encoder_output = encoder_outputs[:,
-1] # (batch_size, encoder_output_dim)
if target_tokens:
targets = target_tokens["tokens"]
target_sequence_length = targets.size()[1]
# The last input from the target is either padding or the end symbol. Either way, we
# don't have to process it.
num_decoding_steps = target_sequence_length - 1
else:
num_decoding_steps = self._max_decoding_steps
decoder_hidden = final_encoder_output
decoder_context = encoder_outputs.new_zeros(batch_size,
self._decoder_output_dim)
last_predictions = None
step_logits = []
step_probabilities = []
step_predictions = []
for timestep in range(num_decoding_steps):
if self.training and torch.rand(
1).item() >= self._scheduled_sampling_ratio:
input_choices = targets[:, timestep]
else:
if timestep == 0:
# For the first timestep, when we do not have targets, we input start symbols.
# (batch_size,)
input_choices = source_mask.new_full(
(batch_size, ), fill_value=self._start_index)
else:
input_choices = last_predictions
decoder_input = self._prepare_decode_step_input(
input_choices, decoder_hidden, encoder_outputs, source_mask)
decoder_hidden, decoder_context = self._decoder_cell(
decoder_input, (decoder_hidden, decoder_context))
# (batch_size, num_classes)
output_projections = self._output_projection_layer(decoder_hidden)
# list of (batch_size, 1, num_classes)
step_logits.append(output_projections.unsqueeze(1))
class_probabilities = F.softmax(output_projections, dim=-1)
_, predicted_classes = torch.max(class_probabilities, 1)
step_probabilities.append(class_probabilities.unsqueeze(1))
last_predictions = predicted_classes
# (batch_size, 1)
step_predictions.append(last_predictions.unsqueeze(1))
# step_logits is a list containing tensors of shape (batch_size, 1, num_classes)
# This is (batch_size, num_decoding_steps, num_classes)
logits = torch.cat(step_logits, 1)
class_probabilities = torch.cat(step_probabilities, 1)
all_predictions = torch.cat(step_predictions, 1)
output_dict = {
"logits": logits,
"class_probabilities": class_probabilities,
"predictions": all_predictions
}
if target_tokens:
target_mask = get_text_field_mask(target_tokens)
loss = self._get_loss(logits, targets, target_mask)
output_dict["loss"] = loss
# TODO: Define metrics
return output_dict
def forward(
self, # type: ignore
text: Dict[str, torch.LongTensor],
spans: torch.IntTensor,
span_labels: torch.IntTensor = None,
metadata: List[Dict[str, Any]] = None) -> Dict[str, torch.Tensor]:
# pylint: disable=arguments-differ
"""
Parameters
----------
text : ``Dict[str, torch.LongTensor]``, required.
The output of a ``TextField`` representing the text of
the document.
spans : ``torch.IntTensor``, required.
A tensor of shape (batch_size, num_spans, 2), representing the inclusive start and end
indices of candidate spans for mentions. Comes from a ``ListField[SpanField]`` of
indices into the text of the document.
span_labels : ``torch.IntTensor``, optional (default = None)
A tensor of shape (batch_size, num_spans), representing the cluster ids
of each span, or -1 for those which do not appear in any clusters.
Returns
-------
An output dictionary consisting of:
top_spans : ``torch.IntTensor``
A tensor of shape ``(batch_size, num_spans_to_keep, 2)`` representing
the start and end word indices of the top spans that survived the pruning stage.
antecedent_indices : ``torch.IntTensor``
A tensor of shape ``(num_spans_to_keep, max_antecedents)`` representing for each top span
the index (with respect to top_spans) of the possible antecedents the model considered.
predicted_antecedents : ``torch.IntTensor``
A tensor of shape ``(batch_size, num_spans_to_keep)`` representing, for each top span, the
index (with respect to antecedent_indices) of the most likely antecedent. -1 means there
was no predicted link.
loss : ``torch.FloatTensor``, optional
A scalar loss to be optimised.
"""
# Shape: (batch_size, document_length, embedding_size)
text_embeddings = self._lexical_dropout(
self._text_field_embedder(text))
document_length = text_embeddings.size(1)
num_spans = spans.size(1)
# Shape: (batch_size, document_length)
text_mask = util.get_text_field_mask(text).float()
# Shape: (batch_size, num_spans)
span_mask = (spans[:, :, 0] >= 0).squeeze(-1).float()
# SpanFields return -1 when they are used as padding. As we do
# some comparisons based on span widths when we attend over the
# span representations that we generate from these indices, we
# need them to be <= 0. This is only relevant in edge cases where
# the number of spans we consider after the pruning stage is >= the
# total number of spans, because in this case, it is possible we might
# consider a masked span.
# Shape: (batch_size, num_spans, 2)
spans = F.relu(spans.float()).long()
# Shape: (batch_size, document_length, encoding_dim)
contextualized_embeddings = self._context_layer(
text_embeddings, text_mask)
# Shape: (batch_size, num_spans, 2 * encoding_dim + feature_size)
endpoint_span_embeddings = self._endpoint_span_extractor(
contextualized_embeddings, spans)
# Shape: (batch_size, num_spans, emebedding_size)
attended_span_embeddings = self._attentive_span_extractor(
text_embeddings, spans)
# Shape: (batch_size, num_spans, emebedding_size + 2 * encoding_dim + feature_size)
span_embeddings = torch.cat(
[endpoint_span_embeddings, attended_span_embeddings], -1)
# Prune based on mention scores.
num_spans_to_keep = int(
math.floor(self._spans_per_word * document_length))
(top_span_embeddings, top_span_mask, top_span_indices,
top_span_mention_scores) = self._mention_pruner(
span_embeddings, span_mask, num_spans_to_keep)
top_span_mask = top_span_mask.unsqueeze(-1)
# Shape: (batch_size * num_spans_to_keep)
# torch.index_select only accepts 1D indices, but here
# we need to select spans for each element in the batch.
# This reformats the indices to take into account their
# index into the batch. We precompute this here to make
# the multiple calls to util.batched_index_select below more efficient.
flat_top_span_indices = util.flatten_and_batch_shift_indices(
top_span_indices, num_spans)
# Compute final predictions for which spans to consider as mentions.
# Shape: (batch_size, num_spans_to_keep, 2)
top_spans = util.batched_index_select(spans, top_span_indices,
flat_top_span_indices)
# Compute indices for antecedent spans to consider.
max_antecedents = min(self._max_antecedents, num_spans_to_keep)
# Now that we have our variables in terms of num_spans_to_keep, we need to
# compare span pairs to decide each span's antecedent. Each span can only
# have prior spans as antecedents, and we only consider up to max_antecedents
# prior spans. So the first thing we do is construct a matrix mapping a span's
# index to the indices of its allowed antecedents. Note that this is independent
# of the batch dimension - it's just a function of the span's position in
# top_spans. The spans are in document order, so we can just use the relative
# index of the spans to know which other spans are allowed antecedents.
# Once we have this matrix, we reformat our variables again to get embeddings
# for all valid antecedents for each span. This gives us variables with shapes
# like (batch_size, num_spans_to_keep, max_antecedents, embedding_size), which
# we can use to make coreference decisions between valid span pairs.
# Shapes:
# (num_spans_to_keep, max_antecedents),
# (1, max_antecedents),
# (1, num_spans_to_keep, max_antecedents)
valid_antecedent_indices, valid_antecedent_offsets, valid_antecedent_log_mask = \
self._generate_valid_antecedents(num_spans_to_keep, max_antecedents, util.get_device_of(text_mask))
# Select tensors relating to the antecedent spans.
# Shape: (batch_size, num_spans_to_keep, max_antecedents, embedding_size)
candidate_antecedent_embeddings = util.flattened_index_select(
top_span_embeddings, valid_antecedent_indices)
# Shape: (batch_size, num_spans_to_keep, max_antecedents)
candidate_antecedent_mention_scores = util.flattened_index_select(
top_span_mention_scores, valid_antecedent_indices).squeeze(-1)
# Compute antecedent scores.
# Shape: (batch_size, num_spans_to_keep, max_antecedents, embedding_size)
span_pair_embeddings = self._compute_span_pair_embeddings(
top_span_embeddings, candidate_antecedent_embeddings,
valid_antecedent_offsets)
# Shape: (batch_size, num_spans_to_keep, 1 + max_antecedents)
coreference_scores = self._compute_coreference_scores(
span_pair_embeddings, top_span_mention_scores,
candidate_antecedent_mention_scores, valid_antecedent_log_mask)
# We now have, for each span which survived the pruning stage,
# a predicted antecedent. This implies a clustering if we group
# mentions which refer to each other in a chain.
# Shape: (batch_size, num_spans_to_keep)
_, predicted_antecedents = coreference_scores.max(2)
# Subtract one here because index 0 is the "no antecedent" class,
# so this makes the indices line up with actual spans if the prediction
# is greater than -1.
predicted_antecedents -= 1
output_dict = {
"top_spans": top_spans,
"antecedent_indices": valid_antecedent_indices,
"predicted_antecedents": predicted_antecedents
}
if span_labels is not None:
# Find the gold labels for the spans which we kept.
pruned_gold_labels = util.batched_index_select(
span_labels.unsqueeze(-1), top_span_indices,
flat_top_span_indices)
antecedent_labels = util.flattened_index_select(
pruned_gold_labels, valid_antecedent_indices).squeeze(-1)
antecedent_labels += valid_antecedent_log_mask.long()
# Compute labels.
# Shape: (batch_size, num_spans_to_keep, max_antecedents + 1)
gold_antecedent_labels = self._compute_antecedent_gold_labels(
pruned_gold_labels, antecedent_labels)
# Now, compute the loss using the negative marginal log-likelihood.
# This is equal to the log of the sum of the probabilities of all antecedent predictions
# that would be consistent with the data, in the sense that we are minimising, for a
# given span, the negative marginal log likelihood of all antecedents which are in the
# same gold cluster as the span we are currently considering. Each span i predicts a
# single antecedent j, but there might be several prior mentions k in the same
# coreference cluster that would be valid antecedents. Our loss is the sum of the
# probability assigned to all valid antecedents. This is a valid objective for
# clustering as we don't mind which antecedent is predicted, so long as they are in
# the same coreference cluster.
coreference_log_probs = util.last_dim_log_softmax(
coreference_scores, top_span_mask)
correct_antecedent_log_probs = coreference_log_probs + gold_antecedent_labels.log(
)
negative_marginal_log_likelihood = -util.logsumexp(
correct_antecedent_log_probs).sum()
self._mention_recall(top_spans, metadata)
self._conll_coref_scores(top_spans, valid_antecedent_indices,
predicted_antecedents, metadata)
output_dict["loss"] = negative_marginal_log_likelihood
if metadata is not None:
output_dict["document"] = [x["original_text"] for x in metadata]
return output_dict
def forward(self, # type: ignore
premise: Dict[str, torch.LongTensor],
hypothesis: Dict[str, torch.LongTensor],
label: torch.IntTensor = None,
metadata: List[Dict[str, Any]] = None) -> Dict[str, torch.Tensor]:
# pylint: disable=arguments-differ
"""
Parameters
----------
premise : Dict[str, torch.LongTensor]
From a ``TextField``
hypothesis : Dict[str, torch.LongTensor]
From a ``TextField``
label : torch.IntTensor, optional, (default = None)
From a ``LabelField``
metadata : ``List[Dict[str, Any]]``, optional, (default = None)
Metadata containing the original tokenization of the premise and
hypothesis with 'premise_tokens' and 'hypothesis_tokens' keys respectively.
Returns
-------
An output dictionary consisting of:
label_logits : torch.FloatTensor
A tensor of shape ``(batch_size, num_labels)`` representing unnormalised log
probabilities of the entailment label.
label_probs : torch.FloatTensor
A tensor of shape ``(batch_size, num_labels)`` representing probabilities of the
entailment label.
loss : torch.FloatTensor, optional
A scalar loss to be optimised.
"""
embedded_premise = self._text_field_embedder(premise)
embedded_hypothesis = self._text_field_embedder(hypothesis)
premise_mask = get_text_field_mask(premise).float()
hypothesis_mask = get_text_field_mask(hypothesis).float()
if self._premise_encoder:
embedded_premise = self._premise_encoder(embedded_premise, premise_mask)
if self._hypothesis_encoder:
embedded_hypothesis = self._hypothesis_encoder(embedded_hypothesis, hypothesis_mask)
projected_premise = self._attend_feedforward(embedded_premise)
projected_hypothesis = self._attend_feedforward(embedded_hypothesis)
# Shape: (batch_size, premise_length, hypothesis_length)
similarity_matrix = self._matrix_attention(projected_premise, projected_hypothesis)
# Shape: (batch_size, premise_length, hypothesis_length)
p2h_attention = last_dim_softmax(similarity_matrix, hypothesis_mask)
# Shape: (batch_size, premise_length, embedding_dim)
attended_hypothesis = weighted_sum(embedded_hypothesis, p2h_attention)
# Shape: (batch_size, hypothesis_length, premise_length)
h2p_attention = last_dim_softmax(similarity_matrix.transpose(1, 2).contiguous(), premise_mask)
# Shape: (batch_size, hypothesis_length, embedding_dim)
attended_premise = weighted_sum(embedded_premise, h2p_attention)
premise_compare_input = torch.cat([embedded_premise, attended_hypothesis], dim=-1)
hypothesis_compare_input = torch.cat([embedded_hypothesis, attended_premise], dim=-1)
compared_premise = self._compare_feedforward(premise_compare_input)
compared_premise = compared_premise * premise_mask.unsqueeze(-1)
# Shape: (batch_size, compare_dim)
compared_premise = compared_premise.sum(dim=1)
compared_hypothesis = self._compare_feedforward(hypothesis_compare_input)
compared_hypothesis = compared_hypothesis * hypothesis_mask.unsqueeze(-1)
# Shape: (batch_size, compare_dim)
compared_hypothesis = compared_hypothesis.sum(dim=1)
aggregate_input = torch.cat([compared_premise, compared_hypothesis], dim=-1)
label_logits = self._aggregate_feedforward(aggregate_input)
label_probs = torch.nn.functional.softmax(label_logits, dim=-1)
output_dict = {"label_logits": label_logits,
"label_probs": label_probs,
"h2p_attention": h2p_attention,
"p2h_attention": p2h_attention}
if label is not None:
loss = self._loss(label_logits, label.long().view(-1))
self._accuracy(label_logits, label)
output_dict["loss"] = loss
if metadata is not None:
output_dict["premise_tokens"] = [x["premise_tokens"] for x in metadata]
output_dict["hypothesis_tokens"] = [x["hypothesis_tokens"] for x in metadata]
return output_dict
def _get_initial_state_and_scores(
self,
question: Dict[str, torch.LongTensor],
table: Dict[str, torch.LongTensor],
world: List[WikiTablesWorld],
actions: List[List[ProductionRuleArray]],
example_lisp_string: List[str] = None,
add_world_to_initial_state: bool = False,
checklist_states: List[ChecklistState] = None) -> Dict:
"""
Does initial preparation and creates an intiial state for both the semantic parsers. Note
that the checklist state is optional, and the ``WikiTablesMmlParser`` is not expected to
pass it.
"""
table_text = table['text']
# (batch_size, question_length, embedding_dim)
embedded_question = self._question_embedder(question)
question_mask = util.get_text_field_mask(question).float()
# (batch_size, num_entities, num_entity_tokens, embedding_dim)
embedded_table = self._question_embedder(table_text,
num_wrapping_dims=1)
table_mask = util.get_text_field_mask(table_text,
num_wrapping_dims=1).float()
batch_size, num_entities, num_entity_tokens, _ = embedded_table.size()
num_question_tokens = embedded_question.size(1)
# (batch_size, num_entities, embedding_dim)
encoded_table = self._entity_encoder(embedded_table, table_mask)
# (batch_size, num_entities, num_neighbors)
neighbor_indices = self._get_neighbor_indices(world, num_entities,
encoded_table)
# Neighbor_indices is padded with -1 since 0 is a potential neighbor index.
# Thus, the absolute value needs to be taken in the index_select, and 1 needs to
# be added for the mask since that method expects 0 for padding.
# (batch_size, num_entities, num_neighbors, embedding_dim)
embedded_neighbors = util.batched_index_select(
encoded_table, torch.abs(neighbor_indices))
neighbor_mask = util.get_text_field_mask(
{
'ignored': neighbor_indices + 1
}, num_wrapping_dims=1).float()
# Encoder initialized to easily obtain a masked average.
neighbor_encoder = TimeDistributed(
BagOfEmbeddingsEncoder(self._embedding_dim, averaged=True))
# (batch_size, num_entities, embedding_dim)
embedded_neighbors = neighbor_encoder(embedded_neighbors,
neighbor_mask)
# entity_types: one-hot tensor with shape (batch_size, num_entities, num_types)
# entity_type_dict: Dict[int, int], mapping flattened_entity_index -> type_index
# These encode the same information, but for efficiency reasons later it's nice
# to have one version as a tensor and one that's accessible on the cpu.
entity_types, entity_type_dict = self._get_type_vector(
world, num_entities, encoded_table)
entity_type_embeddings = self._type_params(entity_types.float())
projected_neighbor_embeddings = self._neighbor_params(
embedded_neighbors.float())
# (batch_size, num_entities, embedding_dim)
entity_embeddings = torch.tanh(entity_type_embeddings +
projected_neighbor_embeddings)
# Compute entity and question word similarity. We tried using cosine distance here, but
# because this similarity is the main mechanism that the model can use to push apart logit
# scores for certain actions (like "n -> 1" and "n -> -1"), this needs to have a larger
# output range than [-1, 1].
question_entity_similarity = torch.bmm(
embedded_table.view(batch_size, num_entities * num_entity_tokens,
self._embedding_dim),
torch.transpose(embedded_question, 1, 2))
question_entity_similarity = question_entity_similarity.view(
batch_size, num_entities, num_entity_tokens, num_question_tokens)
# (batch_size, num_entities, num_question_tokens)
question_entity_similarity_max_score, _ = torch.max(
question_entity_similarity, 2)
# (batch_size, num_entities, num_question_tokens, num_features)
linking_features = table['linking']
linking_scores = question_entity_similarity_max_score
if self._use_neighbor_similarity_for_linking:
# The linking score is computed as a linear projection of two terms. The first is the
# maximum similarity score over the entity's words and the question token. The second
# is the maximum similarity over the words in the entity's neighbors and the question
# token.
#
# The second term, projected_question_neighbor_similarity, is useful when a column
# needs to be selected. For example, the question token might have no similarity with
# the column name, but is similar with the cells in the column.
#
# Note that projected_question_neighbor_similarity is intended to capture the same
# information as the related_column feature.
#
# Also note that this block needs to be _before_ the `linking_params` block, because
# we're overwriting `linking_scores`, not adding to it.
# (batch_size, num_entities, num_neighbors, num_question_tokens)
question_neighbor_similarity = util.batched_index_select(
question_entity_similarity_max_score,
torch.abs(neighbor_indices))
# (batch_size, num_entities, num_question_tokens)
question_neighbor_similarity_max_score, _ = torch.max(
question_neighbor_similarity, 2)
projected_question_entity_similarity = self._question_entity_params(
question_entity_similarity_max_score.unsqueeze(-1)).squeeze(-1)
projected_question_neighbor_similarity = self._question_neighbor_params(
question_neighbor_similarity_max_score.unsqueeze(-1)).squeeze(
-1)
linking_scores = projected_question_entity_similarity + projected_question_neighbor_similarity
feature_scores = None
if self._linking_params is not None:
feature_scores = self._linking_params(linking_features).squeeze(3)
linking_scores = linking_scores + feature_scores
# (batch_size, num_question_tokens, num_entities)
linking_probabilities = self._get_linking_probabilities(
world, linking_scores.transpose(1, 2), question_mask,
entity_type_dict)
# (batch_size, num_question_tokens, embedding_dim)
link_embedding = util.weighted_sum(entity_embeddings,
linking_probabilities)
encoder_input = torch.cat([link_embedding, embedded_question], 2)
# (batch_size, question_length, encoder_output_dim)
encoder_outputs = self._dropout(
self._encoder(encoder_input, question_mask))
# This will be our initial hidden state and memory cell for the decoder LSTM.
final_encoder_output = util.get_final_encoder_states(
encoder_outputs, question_mask, self._encoder.is_bidirectional())
memory_cell = encoder_outputs.new_zeros(batch_size,
self._encoder.get_output_dim())
initial_score = embedded_question.data.new_zeros(batch_size)
action_embeddings, output_action_embeddings, action_biases, action_indices = self._embed_actions(
actions)
_, num_entities, num_question_tokens = linking_scores.size()
flattened_linking_scores, actions_to_entities = self._map_entity_productions(
linking_scores, world, actions)
# To make grouping states together in the decoder easier, we convert the batch dimension in
# all of our tensors into an outer list. For instance, the encoder outputs have shape
# `(batch_size, question_length, encoder_output_dim)`. We need to convert this into a list
# of `batch_size` tensors, each of shape `(question_length, encoder_output_dim)`. Then we
# won't have to do any index selects, or anything, we'll just do some `torch.cat()`s.
initial_score_list = [initial_score[i] for i in range(batch_size)]
encoder_output_list = [encoder_outputs[i] for i in range(batch_size)]
question_mask_list = [question_mask[i] for i in range(batch_size)]
initial_rnn_state = []
for i in range(batch_size):
initial_rnn_state.append(
RnnState(final_encoder_output[i], memory_cell[i],
self._first_action_embedding,
self._first_attended_question, encoder_output_list,
question_mask_list))
initial_grammar_state = [
self._create_grammar_state(world[i], actions[i])
for i in range(batch_size)
]
initial_state_world = world if add_world_to_initial_state else None
initial_state = WikiTablesDecoderState(
batch_indices=list(range(batch_size)),
action_history=[[] for _ in range(batch_size)],
score=initial_score_list,
rnn_state=initial_rnn_state,
grammar_state=initial_grammar_state,
action_embeddings=action_embeddings,
output_action_embeddings=output_action_embeddings,
action_biases=action_biases,
action_indices=action_indices,
possible_actions=actions,
flattened_linking_scores=flattened_linking_scores,
actions_to_entities=actions_to_entities,
entity_types=entity_type_dict,
world=initial_state_world,
example_lisp_string=example_lisp_string,
checklist_state=checklist_states,
debug_info=None)
return {
"initial_state": initial_state,
"linking_scores": linking_scores,
"feature_scores": feature_scores,
"similarity_scores": question_entity_similarity_max_score
}
def forward(
self, # type: ignore
tokens: Dict[str, torch.LongTensor],
spans: torch.LongTensor,
metadata: List[Dict[str, Any]],
pos_tags: Dict[str, torch.LongTensor] = None,
span_labels: torch.LongTensor = None) -> Dict[str, torch.Tensor]:
# pylint: disable=arguments-differ
"""
Parameters
----------
tokens : Dict[str, torch.LongTensor], required
The output of ``TextField.as_array()``, which should typically be passed directly to a
``TextFieldEmbedder``. This output is a dictionary mapping keys to ``TokenIndexer``
tensors. At its most basic, using a ``SingleIdTokenIndexer`` this is: ``{"tokens":
Tensor(batch_size, num_tokens)}``. This dictionary will have the same keys as were used
for the ``TokenIndexers`` when you created the ``TextField`` representing your
sequence. The dictionary is designed to be passed directly to a ``TextFieldEmbedder``,
which knows how to combine different word representations into a single vector per
token in your input.
spans : ``torch.LongTensor``, required.
A tensor of shape ``(batch_size, num_spans, 2)`` representing the
inclusive start and end indices of all possible spans in the sentence.
metadata : List[Dict[str, Any]], required.
A dictionary of metadata for each batch element which has keys:
tokens : ``List[str]``, required.
The original string tokens in the sentence.
gold_tree : ``nltk.Tree``, optional (default = None)
Gold NLTK trees for use in evaluation.
pos_tags : ``List[str]``, optional.
The POS tags for the sentence. These can be used in the
model as embedded features, but they are passed here
in addition for use in constructing the tree.
pos_tags : ``torch.LongTensor``, optional (default = None)
The output of a ``SequenceLabelField`` containing POS tags.
span_labels : ``torch.LongTensor``, optional (default = None)
A torch tensor representing the integer gold class labels for all possible
spans, of shape ``(batch_size, num_spans)``.
Returns
-------
An output dictionary consisting of:
class_probabilities : ``torch.FloatTensor``
A tensor of shape ``(batch_size, num_spans, span_label_vocab_size)``
representing a distribution over the label classes per span.
spans : ``torch.LongTensor``
The original spans tensor.
tokens : ``List[List[str]]``, required.
A list of tokens in the sentence for each element in the batch.
pos_tags : ``List[List[str]]``, required.
A list of POS tags in the sentence for each element in the batch.
num_spans : ``torch.LongTensor``, required.
A tensor of shape (batch_size), representing the lengths of non-padded spans
in ``enumerated_spans``.
loss : ``torch.FloatTensor``, optional
A scalar loss to be optimised.
"""
embedded_text_input = self.text_field_embedder(tokens)
if pos_tags is not None and self.pos_tag_embedding is not None:
embedded_pos_tags = self.pos_tag_embedding(pos_tags)
embedded_text_input = torch.cat(
[embedded_text_input, embedded_pos_tags], -1)
elif self.pos_tag_embedding is not None:
raise ConfigurationError(
"Model uses a POS embedding, but no POS tags were passed.")
mask = get_text_field_mask(tokens)
# Looking at the span start index is enough to know if
# this is padding or not. Shape: (batch_size, num_spans)
span_mask = (spans[:, :, 0] >= 0).squeeze(-1).long()
if span_mask.dim() == 1:
# This happens if you use batch_size 1 and encounter
# a length 1 sentence in PTB, which do exist. -.-
span_mask = span_mask.unsqueeze(-1)
if span_labels is not None and span_labels.dim() == 1:
span_labels = span_labels.unsqueeze(-1)
num_spans = get_lengths_from_binary_sequence_mask(span_mask)
encoded_text = self.encoder(embedded_text_input, mask)
span_representations = self.span_extractor(encoded_text, spans, mask,
span_mask)
if self.feedforward_layer is not None:
span_representations = self.feedforward_layer(span_representations)
logits = self.tag_projection_layer(span_representations)
class_probabilities = last_dim_softmax(logits, span_mask.unsqueeze(-1))
output_dict = {
"class_probabilities": class_probabilities,
"spans": spans,
"tokens": [meta["tokens"] for meta in metadata],
"pos_tags": [meta.get("pos_tags") for meta in metadata],
"num_spans": num_spans
}
if span_labels is not None:
loss = sequence_cross_entropy_with_logits(logits, span_labels,
span_mask)
self.tag_accuracy(class_probabilities, span_labels, span_mask)
output_dict["loss"] = loss
# The evalb score is expensive to compute, so we only compute
# it for the validation and test sets.
batch_gold_trees = [meta.get("gold_tree") for meta in metadata]
if all(batch_gold_trees
) and self._evalb_score is not None and not self.training:
gold_pos_tags: List[List[str]] = [
list(zip(*tree.pos()))[1] for tree in batch_gold_trees
]
predicted_trees = self.construct_trees(
class_probabilities.cpu().data,
spans.cpu().data, num_spans.data, output_dict["tokens"],
gold_pos_tags)
self._evalb_score(predicted_trees, batch_gold_trees)
return output_dict
def forward(
self, # type: ignore
premise: Dict[str, torch.LongTensor],
hypothesis: Dict[str, torch.LongTensor],
label: torch.IntTensor = None,
metadata: List[Dict[str, Any]] = None # pylint:disable=unused-argument
) -> Dict[str, torch.Tensor]:
# pylint: disable=arguments-differ
"""
Parameters
----------
premise : Dict[str, torch.LongTensor]
From a ``TextField``
hypothesis : Dict[str, torch.LongTensor]
From a ``TextField``
label : torch.IntTensor, optional (default = None)
From a ``LabelField``
metadata : ``List[Dict[str, Any]]``, optional, (default = None)
Metadata containing the original tokenization of the premise and
hypothesis with 'premise_tokens' and 'hypothesis_tokens' keys respectively.
Returns
-------
An output dictionary consisting of:
label_logits : torch.FloatTensor
A tensor of shape ``(batch_size, num_labels)`` representing unnormalised log
probabilities of the entailment label.
label_probs : torch.FloatTensor
A tensor of shape ``(batch_size, num_labels)`` representing probabilities of the
entailment label.
loss : torch.FloatTensor, optional
A scalar loss to be optimised.
"""
embedded_premise = self._text_field_embedder(premise)
embedded_hypothesis = self._text_field_embedder(hypothesis)
premise_mask = get_text_field_mask(premise).float()
hypothesis_mask = get_text_field_mask(hypothesis).float()
# apply dropout for LSTM
if self.rnn_input_dropout:
embedded_premise = self.rnn_input_dropout(embedded_premise)
embedded_hypothesis = self.rnn_input_dropout(embedded_hypothesis)
# encode premise and hypothesis
encoded_premise = self._encoder(embedded_premise, premise_mask)
encoded_hypothesis = self._encoder(embedded_hypothesis,
hypothesis_mask)
# Shape: (batch_size, premise_length, hypothesis_length)
similarity_matrix = self._matrix_attention(encoded_premise,
encoded_hypothesis)
# Shape: (batch_size, premise_length, hypothesis_length)
p2h_attention = last_dim_softmax(similarity_matrix, hypothesis_mask)
# Shape: (batch_size, premise_length, embedding_dim)
attended_hypothesis = weighted_sum(encoded_hypothesis, p2h_attention)
# Shape: (batch_size, hypothesis_length, premise_length)
h2p_attention = last_dim_softmax(
similarity_matrix.transpose(1, 2).contiguous(), premise_mask)
# Shape: (batch_size, hypothesis_length, embedding_dim)
attended_premise = weighted_sum(encoded_premise, h2p_attention)
# the "enhancement" layer
premise_enhanced = torch.cat([
encoded_premise, attended_hypothesis, encoded_premise -
attended_hypothesis, encoded_premise * attended_hypothesis
],
dim=-1)
hypothesis_enhanced = torch.cat([
encoded_hypothesis, attended_premise, encoded_hypothesis -
attended_premise, encoded_hypothesis * attended_premise
],
dim=-1)
# The projection layer down to the model dimension. Dropout is not applied before
# projection.
projected_enhanced_premise = self._projection_feedforward(
premise_enhanced)
projected_enhanced_hypothesis = self._projection_feedforward(
hypothesis_enhanced)
# Run the inference layer
if self.rnn_input_dropout:
projected_enhanced_premise = self.rnn_input_dropout(
projected_enhanced_premise)
projected_enhanced_hypothesis = self.rnn_input_dropout(
projected_enhanced_hypothesis)
v_ai = self._inference_encoder(projected_enhanced_premise,
premise_mask)
v_bi = self._inference_encoder(projected_enhanced_hypothesis,
hypothesis_mask)
# The pooling layer -- max and avg pooling.
# (batch_size, model_dim)
v_a_max, _ = replace_masked_values(v_ai, premise_mask.unsqueeze(-1),
-1e7).max(dim=1)
v_b_max, _ = replace_masked_values(v_bi, hypothesis_mask.unsqueeze(-1),
-1e7).max(dim=1)
v_a_avg = torch.sum(v_ai * premise_mask.unsqueeze(-1),
dim=1) / torch.sum(premise_mask, 1, keepdim=True)
v_b_avg = torch.sum(v_bi * hypothesis_mask.unsqueeze(-1),
dim=1) / torch.sum(
hypothesis_mask, 1, keepdim=True)
# Now concat
# (batch_size, model_dim * 2 * 4)
v_all = torch.cat([v_a_avg, v_a_max, v_b_avg, v_b_max], dim=1)
# the final MLP -- apply dropout to input, and MLP applies to output & hidden
if self.dropout:
v_all = self.dropout(v_all)
output_hidden = self._output_feedforward(v_all)
label_logits = self._output_logit(output_hidden)
label_probs = torch.nn.functional.softmax(label_logits, dim=-1)
output_dict = {
"label_logits": label_logits,
"label_probs": label_probs
}
if label is not None:
loss = self._loss(label_logits, label.long().view(-1))
self._accuracy(label_logits, label)
output_dict["loss"] = loss
return output_dict
def forward(self, # type: ignore
question: Dict[str, torch.LongTensor],
passage: Dict[str, torch.LongTensor],
span_start: torch.IntTensor = None,
span_end: torch.IntTensor = None,
metadata: List[Dict[str, Any]] = None) -> Dict[str, torch.Tensor]:
# pylint: disable=arguments-differ
"""
Parameters
----------
question : Dict[str, torch.LongTensor]
From a ``TextField``.
passage : Dict[str, torch.LongTensor]
From a ``TextField``. The model assumes that this passage contains the answer to the
question, and predicts the beginning and ending positions of the answer within the
passage.
span_start : ``torch.IntTensor``, optional
From an ``IndexField``. This is one of the things we are trying to predict - the
beginning position of the answer with the passage. This is an `inclusive` token index.
If this is given, we will compute a loss that gets included in the output dictionary.
span_end : ``torch.IntTensor``, optional
From an ``IndexField``. This is one of the things we are trying to predict - the
ending position of the answer with the passage. This is an `inclusive` token index.
If this is given, we will compute a loss that gets included in the output dictionary.
metadata : ``List[Dict[str, Any]]``, optional
If present, this should contain the question ID, original passage text, and token
offsets into the passage for each instance in the batch. We use this for computing
official metrics using the official SQuAD evaluation script. The length of this list
should be the batch size, and each dictionary should have the keys ``id``,
``original_passage``, and ``token_offsets``. If you only want the best span string and
don't care about official metrics, you can omit the ``id`` key.
Returns
-------
An output dictionary consisting of:
span_start_logits : torch.FloatTensor
A tensor of shape ``(batch_size, passage_length)`` representing unnormalized log
probabilities of the span start position.
span_start_probs : torch.FloatTensor
The result of ``softmax(span_start_logits)``.
span_end_logits : torch.FloatTensor
A tensor of shape ``(batch_size, passage_length)`` representing unnormalized log
probabilities of the span end position (inclusive).
span_end_probs : torch.FloatTensor
The result of ``softmax(span_end_logits)``.
best_span : torch.IntTensor
The result of a constrained inference over ``span_start_logits`` and
``span_end_logits`` to find the most probable span. Shape is ``(batch_size, 2)``
and each offset is a token index.
loss : torch.FloatTensor, optional
A scalar loss to be optimised.
best_span_str : List[str]
If sufficient metadata was provided for the instances in the batch, we also return the
string from the original passage that the model thinks is the best answer to the
question.
"""
embedded_question = self._highway_layer(self._text_field_embedder(question))
embedded_passage = self._highway_layer(self._text_field_embedder(passage))
batch_size = embedded_question.size(0)
passage_length = embedded_passage.size(1)
question_mask = util.get_text_field_mask(question).float()
passage_mask = util.get_text_field_mask(passage).float()
question_lstm_mask = question_mask if self._mask_lstms else None
passage_lstm_mask = passage_mask if self._mask_lstms else None
encoded_question = self._dropout(self._phrase_layer(embedded_question, question_lstm_mask))
encoded_passage = self._dropout(self._phrase_layer(embedded_passage, passage_lstm_mask))
encoding_dim = encoded_question.size(-1)
# Shape: (batch_size, passage_length, question_length)
passage_question_similarity = self._matrix_attention(encoded_passage, encoded_question)
# Shape: (batch_size, passage_length, question_length)
passage_question_attention = util.last_dim_softmax(passage_question_similarity, question_mask)
# Shape: (batch_size, passage_length, encoding_dim)
passage_question_vectors = util.weighted_sum(encoded_question, passage_question_attention)
# We replace masked values with something really negative here, so they don't affect the
# max below.
masked_similarity = util.replace_masked_values(passage_question_similarity,
question_mask.unsqueeze(1),
-1e7)
# Shape: (batch_size, passage_length)
question_passage_similarity = masked_similarity.max(dim=-1)[0].squeeze(-1)
# Shape: (batch_size, passage_length)
question_passage_attention = util.masked_softmax(question_passage_similarity, passage_mask)
# Shape: (batch_size, encoding_dim)
question_passage_vector = util.weighted_sum(encoded_passage, question_passage_attention)
# Shape: (batch_size, passage_length, encoding_dim)
tiled_question_passage_vector = question_passage_vector.unsqueeze(1).expand(batch_size,
passage_length,
encoding_dim)
# Shape: (batch_size, passage_length, encoding_dim * 4)
final_merged_passage = torch.cat([encoded_passage,
passage_question_vectors,
encoded_passage * passage_question_vectors,
encoded_passage * tiled_question_passage_vector],
dim=-1)
modeled_passage = self._dropout(self._modeling_layer(final_merged_passage, passage_lstm_mask))
modeling_dim = modeled_passage.size(-1)
# Shape: (batch_size, passage_length, encoding_dim * 4 + modeling_dim))
span_start_input = self._dropout(torch.cat([final_merged_passage, modeled_passage], dim=-1))
# Shape: (batch_size, passage_length)
span_start_logits = self._span_start_predictor(span_start_input).squeeze(-1)
# Shape: (batch_size, passage_length)
span_start_probs = util.masked_softmax(span_start_logits, passage_mask)
# Shape: (batch_size, modeling_dim)
span_start_representation = util.weighted_sum(modeled_passage, span_start_probs)
# Shape: (batch_size, passage_length, modeling_dim)
tiled_start_representation = span_start_representation.unsqueeze(1).expand(batch_size,
passage_length,
modeling_dim)
# Shape: (batch_size, passage_length, encoding_dim * 4 + modeling_dim * 3)
span_end_representation = torch.cat([final_merged_passage,
modeled_passage,
tiled_start_representation,
modeled_passage * tiled_start_representation],
dim=-1)
# Shape: (batch_size, passage_length, encoding_dim)
encoded_span_end = self._dropout(self._span_end_encoder(span_end_representation,
passage_lstm_mask))
# Shape: (batch_size, passage_length, encoding_dim * 4 + span_end_encoding_dim)
span_end_input = self._dropout(torch.cat([final_merged_passage, encoded_span_end], dim=-1))
span_end_logits = self._span_end_predictor(span_end_input).squeeze(-1)
span_end_probs = util.masked_softmax(span_end_logits, passage_mask)
span_start_logits = util.replace_masked_values(span_start_logits, passage_mask, -1e7)
span_end_logits = util.replace_masked_values(span_end_logits, passage_mask, -1e7)
best_span = self.get_best_span(span_start_logits, span_end_logits)
output_dict = {
"passage_question_attention": passage_question_attention,
"span_start_logits": span_start_logits,
"span_start_probs": span_start_probs,
"span_end_logits": span_end_logits,
"span_end_probs": span_end_probs,
"best_span": best_span,
}
# Compute the loss for training.
if span_start is not None:
loss = nll_loss(util.masked_log_softmax(span_start_logits, passage_mask), span_start.squeeze(-1))
self._span_start_accuracy(span_start_logits, span_start.squeeze(-1))
loss += nll_loss(util.masked_log_softmax(span_end_logits, passage_mask), span_end.squeeze(-1))
self._span_end_accuracy(span_end_logits, span_end.squeeze(-1))
self._span_accuracy(best_span, torch.stack([span_start, span_end], -1))
output_dict["loss"] = loss
# Compute the EM and F1 on SQuAD and add the tokenized input to the output.
if metadata is not None:
output_dict['best_span_str'] = []
question_tokens = []
passage_tokens = []
for i in range(batch_size):
question_tokens.append(metadata[i]['question_tokens'])
passage_tokens.append(metadata[i]['passage_tokens'])
passage_str = metadata[i]['original_passage']
offsets = metadata[i]['token_offsets']
predicted_span = tuple(best_span[i].detach().cpu().numpy())
start_offset = offsets[predicted_span[0]][0]
end_offset = offsets[predicted_span[1]][1]
best_span_string = passage_str[start_offset:end_offset]
output_dict['best_span_str'].append(best_span_string)
answer_texts = metadata[i].get('answer_texts', [])
if answer_texts:
self._squad_metrics(best_span_string, answer_texts)
output_dict['question_tokens'] = question_tokens
output_dict['passage_tokens'] = passage_tokens
return output_dict
