fix issue #125 (#139)

Author: mehdidc

clip_benchmark/metrics/linear_probe.py

@@ -277,7 +277,13 @@ def evaluate(model, train_dataloader, dataloader, fewshot_k, batch_size, num_wor
             peak_idx = find_peak(wd_list, [left, peak_idx, right], feature_train_loader, feature_val_loader, input_shape, output_shape, lr, epochs, autocast, device, verbose, seed)
             step_span //= 2
         best_wd = wd_list[peak_idx]
-        train_loader = feature_train_val_loader
+        if fewshot_k < 0:
+            # if we are doing full training, we use the full training set (train+val)
+            train_loader = feature_train_val_loader
+        else:
+            # if we are doing few-shot learning, we use the few-shot training set only
+            # as adding the validation set will train on more data than intended
+            train_loader = feature_train_loader
     else:
         best_wd = 0
         train_loader = feature_train_loader