check anisous before concat

jamesmkrieger · Nov 3, 2023 · de369b1 · de369b1
1 parent 68479a0
commit de369b1
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/prody/atomic/atomgroup.py b/prody/atomic/atomgroup.py
@@ -240,7 +240,8 @@ def __add__(self, other):
         if self._n_csets:
             if self._n_csets == other._n_csets:
                 new.setCoords(np.concatenate((self._coords, other._coords), 1))
-                new.setAnisous(np.concatenate((self._anisous, other._anisous), 1))
+                if self._anisous is not None and other._anisous is not None:
+                    new.setAnisous(np.concatenate((self._anisous, other._anisous), 1))
                 if self._n_csets > 1:
                     LOGGER.info('All {0} coordinate sets are copied to '
                                 '{1}.'.format(self._n_csets, new.getTitle()))