code: def _op_method(self, data, extra_factor=1.0):
          
  
          # Update threshold with extra factor.
          threshold = self.thresh * extra_factor
  
          if self.lowr_type == 'standard':
              data_matrix = svd_thresh(cube2matrix(data), threshold,
                                       thresh_type=self.thresh_type)
  
          elif self.lowr_type == 'ngole':
              data_matrix = svd_thresh_coef(cube2matrix(data), self.operator,
                                            threshold,
                                            thresh_type=self.thresh_type)
  
          new_data = matrix2cube(data_matrix, data.shape[1:])
  
          # Return updated data.
          return new_data
docs: Operator
  
          This method returns the input data after the singular values have been
          thresholded
  
          Parameters
          ----------
          data : np.ndarray
              Input data array
          extra_factor : float
              Additional multiplication factor
  
          Returns
          -------
          np.ndarray SVD thresholded data