code: def offset_to_window(self, off_x, off_y):
          
          arr_pts = np.asarray((off_x, off_y)).T
          return self.tform['cartesian_to_native'].to_(arr_pts).T[:2]
docs: Convert data offset to window coordinates.
  
          Parameters
          ----------
          off_x, off_y : float or ndarray
              Data offsets.
  
          Returns
          -------
          coord : tuple
              Offset in window coordinates in the form of ``(x, y)``.