function wrf_map_ggp(wks[1]:graphic,lat[*][*]:numeric, lon[*][*]:numeric, \
                in_file[1]:file,opt_args[1]:logical)   

begin
;
; This function creates a map plot, and bases the projection on
; the MAP_PROJ attribute in the given file.
;
;   1. Make a copy of the resource list, and call a function to set
;      some resources common to all map projections.
;
;   2. Determine the projection being used, and set resources based
;      on that projection.
;
;   3. Create the map plot, and draw and advance the frame
;      (if requested).

    if(opt_args.and.isatt(opt_args,"gsnDebugWriteFileName")) then
      wrf_debug_file = get_res_value(opt_args,"gsnDebugWriteFileName",  "")    
    end if

    opts = opt_args      ; Make a copy of the resource list
    opts  = True

;---Set some map resources based on parameters and variables in input file.
    opts = wrf_map_resources_ggp(in_file,lat, lon,opts)

    if(.not.isatt(opts,"mpProjection")) then
      print("wrf_map: Error: no MAP_PROJ attribute in input file")
      return(new(1,graphic))
    else
      projection = opts@mpProjection
    end if

; The default is not to draw the plot or advance the frame, and
; to maximize the plot in the frame.

  opts@gsnDraw       = get_res_value_keep(opts,"gsnDraw",     False)
  opts@gsnFrame      = get_res_value_keep(opts,"gsnFrame",    False)
  opts@gsnMaximize   = get_res_value_keep(opts,"gsnMaximize", True)

  delete_attrs(opts)                             ; Clean up.
  mp = gsn_map(wks,projection,opts)              ; Create map plot.

  if(isvar("wrf_debug_file")) then
    opts@mpProjection = projection
    write_wrf_debug_info(wks,False,False,wrf_debug_file,opts,"wrf_map")
  end if

  return(mp)                                     ; Return.

end