deal with string N

anselm/utils.py

@@ -52,7 +52,10 @@ class Utils(System):
         return  self.ensure_format([v for v, _ in sorted_zip_list]),  [n for _, n in sorted_zip_list]
 
     def acc_pressure(self, value_dict,  form_pressure_acc, n_acc):
-        """ Unit of pressure accumulator is self.unit
+        """ Unit of pressure accumulator is self.unit. The todo Values are 
+        searched and compared in the string format. The N-list must be converted
+        to an integer since operations like > and +1 are applied.
+
         """
         ok = ['Unit' in value_dict,
               'Value' in value_dict,
@@ -61,6 +64,7 @@ class Utils(System):
         if all(ok):
             form_array = self.ensure_format( self.get_value( value_dict , self.unit))
             n_array = value_dict.get('N', [1] * len(form_array))
+            n_array = [int(i)  for i in n_array]
             for i, form_value in enumerate(form_array):
                 if not form_value in  form_pressure_acc:
                     form_pressure_acc.append(form_value)