@property
    def Wz(self):
        """Regularization matrix Wz"""
        if getattr(self, '_Wz', None) is None:
            Ave_z_vol = self.mesh.aveF2CC[:,np.sum(self.mesh.vnF[:2]):].T+self.mesh.vol
            self._Wz = Utils.sdiag((Ave_z_vol*self.alpha_z)**0.5)*self.mesh.cellGradz

            if self.indActive is not None:
                indActive_Fz = (self.mesh.aveFz2CC.T * self.indActive) == 1
                Pac = Utils.speye(self.mesh.nC)[:,self.indActive]
                Pafz = Utils.speye(self.mesh.nFz)[:,indActive_Fz]
                self._Wz = Pafz.T*self._Wz*Pac

        return self._Wz
dataset/ETHPy150Open simpeg/simpeg/SimPEG/Regularization.py/Tikhonov.Wz/operator `*` -> `+`