functions in plclab.i -

             plc_label, z,y,x, levs, ndivs=ndivs, opaque=opaque, lmgrid=lmgrid  
 
     call after plc,z,y,x in order to put labels on an existing contour  
     plot.  If you are going to set the limits (by means of the limits  
     or range functions, or zooming or panning with the mouse), do so  
     before calling plc_label, since it reads the current plot limits.  
     finds points where numeric contours labels can be drawn   
     input  
      z  : array to be contoured  
      y: y coords of array to be contoured  
      x: x coords of array to be contoured  
      levs: contour levels to be labelled  
      ndivs: divide domain into ndvis x ndivs subregions with label in each  
      opaque: if defined, white out below label  
      lmgrid: if defined, draw the subregion perimeters  
      output --- none now  
      authors: Phil Rasch and David Munro  
      last revised: 20 July, 1996 (for 1.3 distribution)