load "gsn_code.ncl"
begin
  wks = gsn_open_wks("x11","example")    ; Open a workstation.
 
  x = (/1.,2.,3.,4.,5.,6.,7.,8.,9.,10./)  ; Define X and Y arrays
  y = (/1.,2.,3.,4.,5.,6.,7.,8.,9.,10./)  ; for XY plot.

  xyres = True                  ; Indicate you want to set some resources.
  xyres@gsnFrame = False        ; Don't advance frame after plot is drawn.
  xy = gsn_xy(wks,x,y,xyres)    ; Draw XY plot.

  cirx = (/ 4.15, 3.26, 2.25, 1.59, 1.59, 2.25, 3.26, 4.15, 4.50/)
  ciry = (/ 8.46, 8.98, 8.80, 8.01, 6.99, 6.20, 6.02, 6.54, 7.50/)

  gsres = True             ; Indicate you want to set some resources.
  gsres@gsFillColor = 4    ; Change fill color.

  gsn_polygon(wks,xy,cirx,ciry,gsres)   ; Draw a filled polygon on the XY plot.
  frame(wks)                            ; Advance the frame.
end