<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _back_transform(self,inplace=True):
 """ Private method to remove log10 transformation from ensemble Parameters inplace: bool back transform self in place Returns ------ ParameterEnsemble : ParameterEnsemble if inplace if False Note ---- Don't call this method unless you know what you are doing """

        if not self.istransformed:
            raise Exception("ParameterEnsemble already back transformed")

        istransformed = self.pst.parameter_data.loc[:,"partrans"] == "log"
        if inplace:
            self.loc[:,istransformed] = 10.0**(self.loc[:,istransformed])
            self.loc[:,:] = (self.loc[:,:] -\
                             self.pst.parameter_data.offset)/\
                             self.pst.parameter_data.scale

            self.__istransformed = False
        else:
            vals = (self.pst.parameter_data.parval1 -\
                    self.pst.parameter_data.offset) /\
                    self.pst.parameter_data.scale
            new_en = ParameterEnsemble(pst=self.pst.get(),data=self.loc[:,:].copy(),
                              columns=self.columns,
                              mean_values=vals,istransformed=False)
            new_en.loc[:,istransformed] = 10.0**(self.loc[:,istransformed])
            new_en.loc[:,:] = (new_en.loc[:,:] -\
                             new_en.pst.parameter_data.offset)/\
                             new_en.pst.parameter_data.scale
            return new_en