function writeada, ada, data
COMPILE_OPT IDL2
ON_ERROR, 0

  sz = size(data)

  xsize = sz[1]
  ysize = sz[2]

  openw, unit, ada, /get_lun

  for x=0, xsize-1 do begin
    for y=0, ysize-1 do begin
      if data[x,y] gt 0 then begin
        for i=0, data[x,y]-1 do begin
          if i eq 0 then d=uint([y,x]) else d = [d,uint([y,x])]
        endfor
        writeu, unit, d
      endif
    endfor
  endfor

  free_lun, unit

end