;================================================
;  lb_6.ncl
;================================================
; Concepts illustrated:
;   - Spanning the full color map in reverse for contour fill
;================================================

load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"  
;************************************************
begin
;************************************************
; open netCDF file and read in data
;************************************************
  in = addfile("atmos.nc","r")
  v  = in->V
;************************************************
; create plot
;************************************************
  wks = gsn_open_wks("ps","lb")                ; open a ncgm file
  gsn_define_colormap(wks, "wgne15")            ; choose colormap

  res                     = True                ; plot mods desired
  res@cnFillOn            = True                ; turn on color 
  res@gsnSpreadColors     = True	        ; use full colormap  
  res@gsnSpreadColorStart  = -1                 ; start with last color
  res@gsnSpreadColorEnd   = 2                   ; end with a beginning color

  plot = gsn_csm_contour_map_ce(wks,v(0,3,:,:),res)  ; create the plot
end