MetaCAT fixes and upgrades (#495)

* MetaCAT fixes and upgrades

Pushing for 3 updates:
1) Removed the check and update for labels with zero data, as this was causing issues during evaluation
2) Resolved an issue where the confusion matrix couldn't be calculated when testing on a single class with an F1 score of 1, as it expected the original number of training classes (3)
3) Updated the attention mask creation to dynamically use the actual pad_idx value instead of assuming it to be 0

* Pushing type fix

* Pushing for type fix

* Fixing type issues

* Pushing change

* Pushing update w/o try except block

For the issue where the confusion matrix couldn't be calculated when testing on a single class with an F1 score of 1, as it expected the original number of training classes (3), pushing an optimized version w/o the try except block

medcat/utils/meta_cat/data_utils.py

@@ -180,23 +180,6 @@ def encode_category_values(data: Dict, existing_category_value2id: Optional[Dict
         category_value2id = {}
 
     category_values = set([x[2] for x in data])
-    # Ensuring that each label has data and checking for class imbalance
-
-    label_data = {key: 0 for key in category_value2id}
-    for i in range(len(data)):
-        if data[i][2] in category_value2id:
-            label_data[data[i][2]] = label_data[data[i][2]] + 1
-
-    # If a label has no data, changing the mapping
-    if 0 in label_data.values():
-        category_value2id_: Dict = {}
-        keys_ls = [key for key, value in category_value2id.items() if value != 0]
-        for k in keys_ls:
-            category_value2id_[k] = len(category_value2id_)
-
-        logger.warning("Labels found with 0 data; updates made\nFinal label encoding mapping: %s",category_value2id_)
-        category_value2id = category_value2id_
-
     for c in category_values:
         if c not in category_value2id:
             category_value2id[c] = len(category_value2id)

medcat/utils/meta_cat/ml_utils.py

@@ -66,7 +66,7 @@ class label of the data
 
     x = torch.tensor(x, dtype=torch.long).to(device)
     # cpos = torch.tensor(cpos, dtype=torch.long).to(device)
-    attention_masks = (x != 0).type(torch.int)
+    attention_masks = (x != pad_id).type(torch.int)
     return x, cpos, attention_masks, y
 
 
@@ -412,10 +412,16 @@ def eval_model(model: nn.Module, data: List, config: ConfigMetaCAT, tokenizer: T
     precision, recall, f1, support = precision_recall_fscore_support(y_eval, predictions, average=score_average)
 
     labels = [name for (name, _) in sorted(config.general['category_value2id'].items(), key=lambda x: x[1])]
+    labels_present_: set = set(predictions)
+    labels_present: List[str] = [str(x) for x in labels_present_]
+
+    if len(labels) != len(labels_present):
+        logger.warning(
+            "The evaluation dataset does not contain all the labels, some labels are missing. Performance displayed for labels found...")
     confusion = pd.DataFrame(
         data=confusion_matrix(y_eval, predictions, ),
-        columns=["true " + label for label in labels],
-        index=["predicted " + label for label in labels],
+        columns=["true " + label for label in labels_present],
+        index=["predicted " + label for label in labels_present],
     )
 
     examples: Dict = {'FP': {}, 'FN': {}, 'TP': {}}