minsaver bugfix (#265)

examples/mnist-convnet.py

@@ -116,6 +116,7 @@ def get_config():
         dataflow=dataset_train,  # the DataFlow instance for training
         callbacks=[
             ModelSaver(),   # save the model after every epoch
+            MaxSaver('validation_accuracy'),  # save the model with highest accuracy (prefix 'validation_')
             InferenceRunner(    # run inference(for validation) after every epoch
                 dataset_test,   # the DataFlow instance used for validation
                 # Calculate both the cost and the error for this DataFlow

tensorpack/callbacks/saver.py

@@ -126,7 +126,7 @@ class MinSaver(Callback):
 
         newname = os.path.join(logger.LOG_DIR,
                                self.filename or
-                               ('max-' if self.reverse else 'min-' + self.monitor_stat))
+                               ('max-' + self.monitor_stat if self.reverse else 'min-' + self.monitor_stat))
         files_to_copy = glob.glob(path + '*')
         for file_to_copy in files_to_copy:
             shutil.copy(file_to_copy, file_to_copy.replace(path, newname))