;*************************************************
; proj_3.ncl
;
; Concepts illustrated:
;   - Drawing filled contours over an orthographic map
;   - Changing the center latitude and longitude for an orthographic projection
;   - Turning off map fill
;
;************************************************
;
; These files are loaded by default in NCL V6.2.0 and newer
; load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
; load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl" 
;************************************************
begin
;************************************************
; read in netCDF file
;************************************************
  a = addfile("may_hgt-hgt_1996-2012_850hPa.nc","r")
;************************************************
; read in data
;************************************************
  printVarSummary(a)
  t = a->regslope(:,:)                                
;************************************************
; create plot
;************************************************
  wks = gsn_open_wks("png","proj")          ; send graphics to PNG file
 

  res                   = True
  res@cnLevelSelectionMode = "ManualLevels"
  res@cnMinLevelValF = -5.00
  res@cnMaxLevelValF = 5.00
  res@cnLevelSpacingF = 0.5


  res@mpProjection      = "Orthographic"       ; choose projection
  res@mpPerimOn         = False             ; turn off box around plot
  res@mpFillOn          = False
  res@mpCenterLonF      = 122.             ; choose center lon
  res@mpCenterLatF      = 45.               ; choose center lat
  res@mpDataBaseVersion = "MediumRes"
  res@mpOutlineOn       = True 
  res@cnFillOn          = True              ; color plot desired
  res@cnFillPalette     = "BlueDarkRed18"     ; select color map
  res@cnLineLabelsOn    = False             ; turn off contour line labels
  res@cnLinesOn         = False             ; turn off contour lines
  
  res@mpGridAndLimbOn        = True               ; turn on lat/lon grid lines
  res@mpGridMaskMode         = "MaskNotOcean"     ; don't draw over land or
                                                  ; inland water bodies

;  res@lbLabelFontHeightF  = 0.015           ; label bar font height
 
  res@tiMainString       = "Test Orthographic Projection"   ; add a title
;  res@tiMainFontHeightF  = .018                               ; font height

;;************************************************************
;;Add shapefiles
;;************************************************************
   load "./shapefile_utils.ncl"
   filename = "sig_regpval_1996-2012.shp"
   print_shapefile_info(filename)
      
   plot = gsn_csm_contour_map(wks,t,res)
   pres = True
   pres@gsMarkerIndex = 1         
   pres@gsMarkerColor = "black"
   poly = gsn_add_shapefile_polymarkers(wks,plot,filename,pres)
end