def obfn_gvar(self):
        """Variable to be evaluated in computing regularisation term,
        depending on 'gEvalY' option value.
        """

        if self.opt['gEvalY']:
            return self.Y
        else:
            return self.cnst_A(None, self.Xf) - self.cnst_c()
Variable to be evaluated in computing regularisation term,
        depending on 'gEvalY' option value.