code: def enforce_bounds(self):
          
          too_big = self.parameter_data.loc[:,"parval1"] > \
              self.parameter_data.loc[:,"parubnd"]
          self.parameter_data.loc[too_big,"parval1"] = \
              self.parameter_data.loc[too_big,"parubnd"]
  
          too_small = self.parameter_data.loc[:,"parval1"] < \
              self.parameter_data.loc[:,"parlbnd"]
          self.parameter_data.loc[too_small,"parval1"] = \
              self.parameter_data.loc[too_small,"parlbnd"]
docs: enforce bounds violation resulting from the
          parameter pertubation calculations