fix bug in to_ndarray causing memory problems

full array was being requested in memory to check shape

funlib/persistence/arrays/array.py

@@ -339,7 +339,7 @@ def to_ndarray(self, roi, fill_value=0):
 
         shape = roi.shape / self.voxel_size
         data = np.zeros(
-            self[self.roi].shape[: self.channel_dims] + shape, dtype=self.data.dtype
+            self.shape[: self.channel_dims] + shape, dtype=self.data.dtype
         )
         if fill_value != 0:
             data[:] = fill_value