Merge pull request #9 from JosefBuchner/handle_missing_predictions

return instance_dice of 0.0 instead of NaN when missing predictions

panoptica/result.py

@@ -171,6 +171,8 @@ def instance_dice(self) -> float:
         Returns:
             float: Average Dice coefficient.
         """
+        if self.tp == 0: 
+            return 0.0
         return np.sum(self._dice_list) / self.tp
 
     @property