Update modeling_cxrbert.py

modeling_cxrbert.py

@@ -3,6 +3,7 @@
 #  Licensed under the MIT License (MIT). See LICENSE in the repo root for license information.
 #  ------------------------------------------------------------------------------------------
 
+from dataclasses import dataclass
 from typing import Any, Optional, Tuple, Union
 
 import torch
@@ -16,20 +17,24 @@ from .configuration_cxrbert import CXRBertConfig
 
 BERTTupleOutput = Tuple[T, T, T, T, T]
 
+
+@dataclass
 class CXRBertOutput(ModelOutput):
     last_hidden_state: torch.FloatTensor
-    logits: torch.FloatTensor
+    logits: Optional[torch.FloatTensor] = None
     cls_projected_embedding: Optional[torch.FloatTensor] = None
     hidden_states: Optional[Tuple[torch.FloatTensor]] = None
     attentions: Optional[Tuple[torch.FloatTensor]] = None
 
 
 class BertProjectionHead(nn.Module):
-    '''
-    Projection head to be used with BERT CLS token, it's similar to `BertPredictionHeadTransform` in HuggingFace library.
-    :param config: CXRBertConfig
-    :return: (batch_size, output_size)
-    '''
+    """Projection head to be used with BERT CLS token.
+
+    This is similar to ``BertPredictionHeadTransform`` in HuggingFace.
+
+    :param config: Configuration for BERT.
+    """
+
     def __init__(self, config: CXRBertConfig) -> None:
         super().__init__()
         self.dense_to_hidden = nn.Linear(config.hidden_size, config.projection_size)
@@ -50,13 +55,13 @@ class CXRBertModel(BertForMaskedLM):
     """
     Implements the CXR-BERT model outlined in the manuscript:
     Boecking et al. "Making the Most of Text Semantics to Improve Biomedical Vision-Language Processing", 2022
-    https://arxiv.org/abs/2204.09817
+    https://link.springer.com/chapter/10.1007/978-3-031-20059-5_1
 
-    Extends the HuggingFace BertForMaskedLM model by adding a separate projection head. The projection "[CLS]" token is used to align
-    the latent vectors of image and text modalities.
+    Extends the HuggingFace BertForMaskedLM model by adding a separate projection head. The projection "[CLS]" token is
+    used to align the latent vectors of image and text modalities.
     """
 
-    config_class = CXRBertConfig
+    config_class = CXRBertConfig  # type: ignore
 
     def __init__(self, config: CXRBertConfig):
         super().__init__(config)
@@ -78,21 +83,24 @@ class CXRBertModel(BertForMaskedLM):
         return_dict: Optional[bool] = None,
         **kwargs: Any
     ) -> Union[BERTTupleOutput, CXRBertOutput]:
-
         return_dict = return_dict if return_dict is not None else self.config.use_return_dict
 
-        bert_for_masked_lm_output = super().forward(input_ids=input_ids,
-                                                    attention_mask=attention_mask,
-                                                    token_type_ids=token_type_ids,
-                                                    position_ids=position_ids,
-                                                    head_mask=head_mask,
-                                                    inputs_embeds=inputs_embeds,
-                                                    output_attentions=output_attentions,
-                                                    output_hidden_states=True,
-                                                    return_dict=True)
+        bert_for_masked_lm_output = super().forward(
+            input_ids=input_ids,
+            attention_mask=attention_mask,
+            token_type_ids=token_type_ids,
+            position_ids=position_ids,
+            head_mask=head_mask,
+            inputs_embeds=inputs_embeds,
+            output_attentions=output_attentions,
+            output_hidden_states=True,
+            return_dict=True,
+        )
 
         last_hidden_state = bert_for_masked_lm_output.hidden_states[-1]
-        cls_projected_embedding = self.cls_projection_head(last_hidden_state[:, 0, :]) if output_cls_projected_embedding else None
+        cls_projected_embedding = (
+            self.cls_projection_head(last_hidden_state[:, 0, :]) if output_cls_projected_embedding else None
+        )
 
         if return_dict:
             return CXRBertOutput(
@@ -108,21 +116,31 @@ class CXRBertModel(BertForMaskedLM):
                 bert_for_masked_lm_output.logits,
                 cls_projected_embedding,
                 bert_for_masked_lm_output.hidden_states,
-                bert_for_masked_lm_output.attentions,)
+                bert_for_masked_lm_output.attentions,
+            )
 
-    def get_projected_text_embeddings(self, input_ids: torch.Tensor, attention_mask: torch.Tensor) -> torch.Tensor:
+    def get_projected_text_embeddings(
+        self, input_ids: torch.Tensor, attention_mask: torch.Tensor, normalize_embeddings: bool = True
+    ) -> torch.Tensor:
         """
         Returns l2-normalised projected cls token embeddings for the given input token ids and attention mask.
         The joint latent space is trained using a contrastive objective between image and text data modalities.
 
         :param input_ids: (batch_size, sequence_length)
         :param attention_mask: (batch_size, sequence_length)
+        :param normalize_embeddings: Whether to l2-normalise the embeddings.
         :return: (batch_size, projection_size)
         """
 
-        outputs = self.forward(input_ids=input_ids, attention_mask=attention_mask, 
-                               output_cls_projected_embedding=True, return_dict=True)
+        outputs = self.forward(
+            input_ids=input_ids, attention_mask=attention_mask, output_cls_projected_embedding=True, return_dict=True
+        )
         assert isinstance(outputs, CXRBertOutput)
 
-        normalized_cls_embedding = F.normalize(outputs.cls_projected_embedding, dim=1)
-        return normalized_cls_embedding
+        cls_projected_embedding = outputs.cls_projected_embedding
+        assert cls_projected_embedding is not None
+
+        if normalize_embeddings:
+            return F.normalize(cls_projected_embedding, dim=1)
+
+        return cls_projected_embedding