code: def map(self, coords):
          
          m = np.empty(coords.shape)
          m[:, :3] = (coords[:, :3] * self.scale[np.newaxis, :3] +
                      coords[:, 3:] * self.translate[np.newaxis, :3])
          m[:, 3] = coords[:, 3]
          return m
docs: Map coordinates
  
          Parameters
          ----------
          coords : array-like
              Coordinates to map.
  
          Returns
          -------
          coords : ndarray
              Coordinates.