def concatenate_encoder_outputs(self,
encoder_outputs: BaseModelOutputWithPastAndCrossAttentions,
encoder_attention_mask: torch.LongTensor,
passage_mask: Optional[torch.LongTensor] = None) -> \
Tuple[BaseModelOutputWithPastAndCrossAttentions, torch.LongTensor]:
# batch x contexts x sequence_len x hidden_dim
hidden_states = encoder_outputs['last_hidden_state']
assert hidden_states.shape[:2] == encoder_attention_mask.shape, \
f"Shapes of mask and hidden states do not match! {str(hidden_states.shape[:2])} vs {str(encoder_attention_mask.shape)}"
# concatenate hidden states into the same dimension
# supported subsequence types: document, question+document
# batch x contexts x sequence_len x hidden_dim -> batch x contexts * (subsequence_len_without_padding !variable size) x hidden_dim
if self.config.fusion_strategy == "passages":
mask = encoder_attention_mask.bool().view(
-1) & passage_mask.bool().view(-1)
elif self.config.fusion_strategy == "allinputs":
mask = encoder_attention_mask.bool().view(-1)
hidden_states = hidden_states.view(
-1, hidden_states.shape[-1])[mask].unsqueeze(0)
# there is no padding now
attention_mask = torch.ones(hidden_states.size()[:2],
device=hidden_states.device,
dtype=torch.long)
encoder_outputs['last_hidden_state'] = hidden_states
return encoder_outputs, attention_mask
def predict(self, inputs: torch.FloatTensor, mask: torch.LongTensor) -> List:
bool_mask = mask.bool()
if self.tag_projection:
inputs = self.tag_projection(inputs)
scores = inputs * mask.unsqueeze(-1)
best_paths = self.base.viterbi_tags(scores, bool_mask, top_k=self.top_k)
# Just get the top tags and ignore the scores.
tags = cast(List[List[int]], [x[0][0] for x in best_paths])
return tags
def forward(self, embedded: torch.Tensor,
attention_mask: torch.LongTensor) -> torch.Tensor:
"""
Args:
embedded: batch_size, pad_len, embed_dim
attention_mask: batch_size, pad_len
Returns:
batch_size, pad_len
"""
cosine = self.cosine_similarity_to_u(embedded) # batch_size, pad_len
masked = cosine.masked_fill(~attention_mask.bool(), float('-inf'))
attention = torch.softmax(masked, dim=1) # batch_size, pad_len
return attention
def __call__(self, prediction_match_labels: torch.Tensor,
gold_match_labels: torch.Tensor,
mask: torch.LongTensor) -> Dict:
"""
真正的计算 metric f1。
目前仅仅计算了全部的 F1, 也就是 f1-overall, 而对于每一个实体的指标并没有计算。
原始的论文中没有这一部分，所以暂时没有计算每一种类型实体的指标。
ToDo:// 增加每一种实体类型的指标计算
:param prediction_match_labels: 预测的 match label indices
:param gold_match_labels: golden label indices
:param mask: mask
:return: metric dict
"""
mask = mask.bool()
batch_size, seq_length = mask.size()
match_label_mask = (mask.unsqueeze(-1).expand(-1, -1, seq_length)
& mask.unsqueeze(1).expand(-1, seq_length, -1))
# 取上三角
match_label_mask = torch.triu(
match_label_mask, 0) # start should be less or equal to end
# 判断多少个是一样的
prediction_match_labels = prediction_match_labels & match_label_mask
gold_match_labels = gold_match_labels & match_label_mask
true_positive_value = (gold_match_labels
& prediction_match_labels).long().sum()
true_positives = {MRCF1Metric.All: true_positive_value}
false_positive_value = (~gold_match_labels
& prediction_match_labels).long().sum()
false_positives = {MRCF1Metric.All: false_positive_value}
false_negative_value = (gold_match_labels
& ~prediction_match_labels).long().sum()
false_negatives = {MRCF1Metric.All: false_negative_value}
self._true_positives[MRCF1Metric.All] += true_positive_value
self._false_positives[MRCF1Metric.All] += false_positive_value
self._false_negatives[MRCF1Metric.All] += false_negative_value
return self._metric(true_positives=true_positives,
false_positives=false_positives,
false_negatives=false_negatives)
def dot_product_self_attention(
embedded: torch.Tensor,
attention_mask: torch.LongTensor) -> torch.Tensor:
"""
Self attention computed from dot product with other embedded word
vectors in the same sequence.
Args:
embedded: batch_size, pad_len, embed_dim
attention_mask: batch_size, pad_len
Returns:
batch_size, pad_len
"""
summed_dot_prod = torch.bmm(embedded, embedded.transpose(1, 2)).sum(
2) # batch_size, pad_len
masked = summed_dot_prod.masked_fill(~attention_mask.bool(), float('-inf'))
attention = torch.softmax(masked, dim=1) # batch_size, pad_len
return attention
def forward(
self, inputs: torch.FloatTensor, mask: torch.LongTensor,
labels: torch.LongTensor = None, reduction: str = None,
) -> Dict[str, Any]:
bool_mask = mask.bool()
if self.tag_projection:
inputs = self.tag_projection(inputs)
scores = inputs * mask.unsqueeze(-1)
best_paths = self.base.viterbi_tags(scores, bool_mask, top_k=self.top_k)
# Just get the top tags and ignore the scores.
tags = cast(List[List[int]], [x[0][0] for x in best_paths])
if labels is None:
loss = torch.tensor(0, dtype=torch.float, device=inputs.device)
else:
# Add negative log-likelihood as loss
loss = self.base(scores, labels, bool_mask, reduction)
return dict(scores=scores, predicted_tags=tags, loss=loss)
def forward(
self, # pylint: disable=arguments-differ
embeddings: torch.FloatTensor,
mask: torch.LongTensor,
num_items_to_keep: Union[int, torch.LongTensor],
class_scores: torch.FloatTensor = None,
gold_labels: torch.long = None
) -> Tuple[torch.FloatTensor, torch.LongTensor, torch.LongTensor,
torch.FloatTensor]:
"""
Extracts the top-k scoring items with respect to the scorer. We additionally return
the indices of the top-k in their original order, not ordered by score, so that downstream
components can rely on the original ordering (e.g., for knowing what spans are valid
antecedents in a coreference resolution model). May use the same k for all sentences in
minibatch, or different k for each.
Parameters
----------
embeddings : ``torch.FloatTensor``, required.
A tensor of shape (batch_size, num_items, embedding_size), containing an embedding for
each item in the list that we want to prune.
mask : ``torch.LongTensor``, required.
A tensor of shape (batch_size, num_items), denoting unpadded elements of
``embeddings``.
num_items_to_keep : ``Union[int, torch.LongTensor]``, required.
If a tensor of shape (batch_size), specifies the number of items to keep for each
individual sentence in minibatch.
If an int, keep the same number of items for all sentences.
class_scores:
Class scores to be used with entity beam.
candidate_labels: If in debugging mode, use gold labels to get beam.
Returns
-------
top_embeddings : ``torch.FloatTensor``
The representations of the top-k scoring items.
Has shape (batch_size, max_num_items_to_keep, embedding_size).
top_mask : ``torch.LongTensor``
The corresponding mask for ``top_embeddings``.
Has shape (batch_size, max_num_items_to_keep).
top_indices : ``torch.IntTensor``
The indices of the top-k scoring items into the original ``embeddings``
tensor. This is returned because it can be useful to retain pointers to
the original items, if each item is being scored by multiple distinct
scorers, for instance. Has shape (batch_size, max_num_items_to_keep).
top_item_scores : ``torch.FloatTensor``
The values of the top-k scoring items.
Has shape (batch_size, max_num_items_to_keep, 1).
num_items_kept
"""
# If an int was given for number of items to keep, construct tensor by repeating the value.
if isinstance(num_items_to_keep, int):
batch_size = mask.size(0)
# Put the tensor on same device as the mask.
num_items_to_keep = num_items_to_keep * torch.ones(
[batch_size], dtype=torch.long, device=mask.device)
mask = mask.unsqueeze(-1)
num_items = embeddings.size(1)
# Shape: (batch_size, num_items, 1)
# If entity beam is one, use the class scores. Else ignore them and use the scorer.
if self._entity_beam:
scores, _ = class_scores.max(dim=-1)
scores = scores.unsqueeze(-1)
# If gold beam is one, give a score of 0 wherever the gold label is non-zero (indicating a
# non-null label), otherwise give a large negative number.
elif self._gold_beam:
scores = torch.where(
gold_labels > 0,
torch.zeros_like(gold_labels, dtype=torch.float),
-1e20 * torch.ones_like(gold_labels, dtype=torch.float))
scores = scores.unsqueeze(-1)
else:
scores = self._scorer(embeddings)
# If we're only keeping items that score above a given threshold, change the number of kept
# items here.
if self._min_score_to_keep is not None:
num_good_items = torch.sum(scores > self._min_score_to_keep,
dim=1).squeeze()
num_items_to_keep = torch.min(num_items_to_keep, num_good_items)
# If gold beam is on, keep the gold items.
if self._gold_beam:
num_items_to_keep = torch.sum(gold_labels > 0, dim=1)
# Always keep at least one item to avoid edge case with empty matrix.
max_items_to_keep = max(num_items_to_keep.max().item(), 1)
if scores.size(-1) != 1 or scores.dim() != 3:
raise ValueError(
f"The scorer passed to Pruner must produce a tensor of shape"
f"(batch_size, num_items, 1), but found shape {scores.size()}")
# Make sure that we don't select any masked items by setting their scores to be very
# negative. These are logits, typically, so -1e20 should be plenty negative.
# NOTE(`mask` needs to be a byte tensor now.)
scores = util.replace_masked_values(scores, mask.bool(), -1e20)
# Shape: (batch_size, max_num_items_to_keep, 1)
_, top_indices = scores.topk(max_items_to_keep, 1)
# Mask based on number of items to keep for each sentence.
# Shape: (batch_size, max_num_items_to_keep)
top_indices_mask = util.get_mask_from_sequence_lengths(
num_items_to_keep, max_items_to_keep)
top_indices_mask = top_indices_mask.bool()
# Shape: (batch_size, max_num_items_to_keep)
top_indices = top_indices.squeeze(-1)
# Fill all masked indices with largest "top" index for that sentence, so that all masked
# indices will be sorted to the end.
# Shape: (batch_size, 1)
fill_value, _ = top_indices.max(dim=1)
fill_value = fill_value.unsqueeze(-1)
# Shape: (batch_size, max_num_items_to_keep)
top_indices = torch.where(top_indices_mask, top_indices, fill_value)
# Now we order the selected indices in increasing order with
# respect to their indices (and hence, with respect to the
# order they originally appeared in the ``embeddings`` tensor).
top_indices, _ = torch.sort(top_indices, 1)
# Shape: (batch_size * max_num_items_to_keep)
# torch.index_select only accepts 1D indices, but here
# we need to select items for each element in the batch.
flat_top_indices = util.flatten_and_batch_shift_indices(
top_indices, num_items)
# Shape: (batch_size, max_num_items_to_keep, embedding_size)
top_embeddings = util.batched_index_select(embeddings, top_indices,
flat_top_indices)
# Combine the masks on spans that are out-of-bounds, and the mask on spans that are outside
# the top k for each sentence.
# Shape: (batch_size, max_num_items_to_keep)
sequence_mask = util.batched_index_select(mask, top_indices,
flat_top_indices)
sequence_mask = sequence_mask.squeeze(-1).bool()
top_mask = top_indices_mask & sequence_mask
top_mask = top_mask.long()
# Shape: (batch_size, max_num_items_to_keep, 1)
top_scores = util.batched_index_select(scores, top_indices,
flat_top_indices)
return top_embeddings, top_mask, top_indices, top_scores, num_items_to_keep
