code: def sigma_data(self):
          
          sigmas = self.model.sigmas
          return OrderedDict((sigmas[var], self.data[sigmas[var]])
                             for var in self.model.dependent_vars)
docs: Read-only Property
  
          :return: Data belonging to each sigma variable as a dict with
                   variable names as key, data as value.
          :rtype: collections.OrderedDict