Add label encoding in MiniImagenet

Author: tristandeleu

datasets.py

@@ -58,17 +58,25 @@ def __init__(self, root, train=False, valid=False, test=False,
             next(reader) # Skip the header
             for line in reader:
                 self._data.append(tuple(line))
+        self._fit_label_encoding()
 
     def __getitem__(self, index):
         filename, label = self._data[index]
         image = pil_loader(os.path.join(self.image_folder, filename))
+        label = self._label_encoder[label]
         if self.transform is not None:
             image = self.transform(image)
         if self.target_transform is not None:
             label = self.target_transform(label)
 
         return image, label
 
+    def _fit_label_encoding(self):
+        _, labels = zip(*self._data)
+        unique_labels = set(labels)
+        self._label_encoder = dict((label, idx)
+            for (idx, label) in enumerate(unique_labels))
+
     def _check_exists(self):
         return (os.path.exists(self.image_folder) 
             and os.path.exists(self.split_filename))

prior_miniimagenet.py

@@ -102,7 +102,7 @@ def main(args):
     best_loss = -1.
     for epoch in range(args.num_epochs):
         train(train_loader, model, prior, optimizer, args, writer)
-        loss, _ = test(valid_loader, model, prior, args, writer)
+        loss = test(valid_loader, model, prior, args, writer)
 
         # reconstruction = generate_samples(fixed_images, model, args)
         # grid = make_grid(reconstruction.cpu(), nrow=8, range=(-1, 1), normalize=True)