pro print_for_xmgr, x,y, set=set, file=filename
;
; print out x and y values for to be read by xmgr
;
Nbins = N_elements(x)
if N_elements(set) eq 0 then set=0
if N_elements(filename) gt 0 then begin
   openw, lun, filename, /get_lun, /APPEND
   printf, lun, '@TARGET S', strcompress(string(set), /remove_all)
   printf, lun, '@TYPE xy'
   for j=0L, Nbins-1 do begin
      printf, lun, '    ',x[j], y[j]
   endfor
   printf, lun, '&'
   close, lun
endif else begin
  if N_elements(set) eq 0 then set=0
  nbins = N_elements(x)
  print, '@TARGET S', strcompress(string(set), /remove_all)
  print, '@TYPE xy'
   for j=0L, Nbins-1 do begin
      print, '    ',x[j], y[j]
   endfor
   print, '&'
endelse

end