def obfn_dfd(self):
        r"""Compute data fidelity term :math:`(1/2) \| D X B - S \|_2^2`.
        """

        DXBf = sl.dot(self.B, sl.inner(self.Df, self.obfn_fvarf(),
                                       axis=self.cri.axisM),
                       axis=self.cri.axisC)
        Ef = DXBf - self.Sf
        return sl.rfl2norm2(Ef, self.S.shape, axis=self.cri.axisN) / 2.0
def obfn_dfd ( self ) : DXBf = sl . dot ( self . B , sl . inner ( self . Df , self . obfn_fvarf ( ) , axis = self . cri . axisM ) , axis = self . cri . axisC ) Ef = DXBf - self . Sf return sl . rfl2norm2 ( Ef , self . S . shape , axis = self . cri . axisN ) / 2.0
r"""Compute data fidelity term :math:`(1/2) \| D X B - S \|_2^2`.