Fix longruns

lbmpy/boundaries/boundaryconditions.py

@@ -626,7 +626,7 @@ class DiffusionDirichlet(LbBoundary):
         return [LbmWeightInfo(lb_method, self._data_type)]
 
     def __call__(self, f_out, f_in, dir_symbol, inv_dir, lb_method, index_field):
-        assert lb_method.conserved_quantity_computation.zero_centered_pdfs is False, \
+        assert lb_method.conserved_quantity_computation.zero_centered_pdfs is True, \
             "DiffusionDirichlet only works for methods with normal pdfs storage -> set zero_centered=False"
         weight_info = LbmWeightInfo(lb_method, self._data_type)
         w_dir = weight_info.weight_of_direction(dir_symbol, lb_method)