;----------------------------------------------------------------------
; Concepts illustrated:
;   - Drawing contours over a map using a native lat,lon grid
;   - Zooming in on a particular area on a map
;----------------------------------------------------------------------
; 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 data and start graphics
  a    = addfile("GRISO_Vaia.nc","r")

;DEBUG
;printVarSummary(a)
;print(a)
;exit


;--------------------- EXAMPLES -------------------------------------
;For example, the following NCL statements assign two coordinate variables to a temperature variable.

;; create the temperature variable ( a 5x4 array of data)
;temp = new((/5,4/), float)
;
;; assign dimension names
;temp!0 = "lon"
;temp!1 = "lat"
;
;; initialize the values in the coordinate arrays
;lon_coordinates = (/-90, -85, -80, -75, -70/)
;lat_coordinates = (/0, 20, 40, 60/)
;
;; assign the coordinate arrays to the variable
;; Note that the coordinate variables must have the same name and
;; size as their corresponding dimension.
;temp&lon = lon_coordinates
;temp&lat = lat_coordinates
;--------------------- END EXAMPLES -------------------------------------

  time = a->Time_GRISO
  lat  = a->lat          ; Needed only for projection information
  lon  = a->lon
  prec = a->PR_GRISO

; assign dimension names
  prec!0="time"
  prec!1="lon"
  prec!2="lat"

; initialize the values in the coordinate arrays
  
  prec&lat= lat(:,0)
  prec&lon= lon(0,:)

; assign the coordinate arrays to the variable
  prec&lat@units="degrees_north"
  prec&lon@units="degrees_east"

;DEBUG
;printVarSummary(time)
;print(temp)
;printVarSummary(lat)
;print(lat)
;printVarSummary(lon)
;print(lon)
;printVarSummary(prec)
;printVarSummary(prec&lon)
;printVarSummary(prec&lat)
;print(prec)
;exit

  type = "x11"
  wks = gsn_open_wks(type,"dataonmap_native")

;---Set some resources
  res                = True

  res@gsnMaximize    = True     ; maximize plot in frame

  res@cnFillOn       = True     ; turn on contour fill
  res@cnLinesOn      = False    ; turn off contour lines
  res@cnLineLabelsOn = False    ; turn off contour line labels

  res@tfDoNDCOverlay    = True              ; REQUIRED for plotting on native grid  
  res@gsnAddCyclic = False

; res@tfDoNDCOverlay    = "NDCViewport"     ; NCL V6.5.0 or later
;  res@mpLimitMode       = "Corners"         ; choose range of map
;  res@mpLeftCornerLatF  = lat@corners(0)
;  res@mpLeftCornerLonF  = lon@corners(0)
;  res@mpRightCornerLatF = lat@corners(2)
;  res@mpRightCornerLonF = lon@corners(2)
;
;  res@mpProjection        = lat@mpProjection
;  res@mpLambertMeridianF  = lat@mpLambertMeridianF
;  res@mpLambertParallel1F = lat@mpLambertParallel1F
;  res@mpLambertParallel2F = lat@mpLambertParallel2F
;
;  res@pmTickMarkDisplayMode = "Always"    ; better map tickmarks
;
;  res@tiMainString   = "Plotting data on its native grid"

;---Make contour plot
  plot = gsn_csm_contour_map(wks,prec(0,:,:),res)

end