Added assert to data loader (checking label smoothing works)

PyTorchClassification/data_loader.py

@@ -346,6 +346,10 @@ class JSONDataset(data.Dataset):
         if (dataFormat2017):
             # self.tax_levels = ['id', 'name', 'supercategory']
             self.tax_levels = ['id', 'name']
+            if label_smoothing > 0:
+                assert len(self.tax_levels) == 3, "Please comment in the line above to include the taxonomy " + \
+                    "level 'supercategory' in order for label smoothing to work. It should look like this: " + \
+                    "self.tax_levels = ['id', 'name', 'supercategory']"
         else:
             self.tax_levels = ['id', 'genus', 'family', 'order', 'class', 'phylum', 'kingdom']
                                #8142, 4412,    1120,     273,     57,      25,       6