diff --git a/LDDsimulation/domainPatch.py b/LDDsimulation/domainPatch.py
index 81121e0db045ef95d9b12919ebe1829bd248a8ef..95e663d91abcd1369580abd5872158b5462d8503 100644
--- a/LDDsimulation/domainPatch.py
+++ b/LDDsimulation/domainPatch.py
@@ -1252,14 +1252,14 @@ class DomainPatch(df.SubDomain):
                 # subsequent_diff.rename("pi_"+"{}".format(phase)+"-pim1_"+"{}".format(phase), #
                 #             "pressure(t="+"{}".format(t)+")_"+"{}".format(phase)
                 #             )
-                subsequent_diff.rename(data_set_name)
+                subsequent_diff.rename(data_set_name,data_set_name)
                 file.write(subsequent_diff, i)
-                
-                abs_subsequent_diff = df.Function(subdomain.function_space["pressure"][phase])
+
+                abs_subsequent_diff = df.Function(self.function_space["pressure"][phase])
                 np_subsequent_diff = subsequent_diff.vector()[:]
                 abs_diff_tmp = np.fabs(np_subsequent_diff)
                 abs_subsequent_diff.vector()[:] = abs_diff_tmp
-                abs_subsequent_diff.rename(data_set_name_abs)
+                abs_subsequent_diff.rename(data_set_name_abs,data_set_name_abs)
                 file.write(abs_subsequent_diff, i)
 
 # END OF CLASS DomainPatch