docs: def Lc(self,value):
          """ set col rotation """
          assert value.shape[0]==self._P, 'Lc dimension mismatch'
          assert value.shape[1]==self._P, 'Lc dimension mismatch'
          self._Lc = value
          self.clear_cache('Astar','Ystar','Yhat','Xstar','Xhat',
                           'Areml','Areml_eigh','Areml_chol','Areml_inv','beta_hat','B_hat',
                           'LRLdiag_Xhat_tens','LRLdiag_Yhat','Areml_grad',
                           'beta_grad','Xstar_beta_grad','Zstar','DLZ')