code: def add_transform_columns(self):
          
          for col in ["parval1","parlbnd","parubnd","increment"]:
              if col not in self.parameter_data.columns:
                  continue
              self.parameter_data.loc[:,col+"_trans"] = (self.parameter_data.loc[:,col] *
                                                            self.parameter_data.scale) +\
                                                           self.parameter_data.offset
              #isnotfixed = self.parameter_data.partrans != "fixed"
              islog = self.parameter_data.partrans == "log"
              self.parameter_data.loc[islog,col+"_trans"] = \
                  self.parameter_data.loc[islog,col+"_trans"].\
                      apply(lambda x:np.log10(x))
docs: add transformed values to the Pst.parameter_data attribute