SPECTRUM /CORNER

        [GREG3\]SPECTRUM OutSpec InCube [Mask] /CORNER Imin Imax Jmin Jmax
      [/PLANE First Last] /MEAN] or /SUM

      Restricts  the  computation  to  the  specified 2-D region of the data
    cube.  One of the mutually exclusive  options  /MEAN  or  /SUM  must  be
    present.