DKRZ NCL contour lines plot example (rectilinear grid)

DKRZ NCL example script:

;-----------------------------------------------------------------
;
;  NCL Doc Example:  NCL_contour_lines_map.ncl
;
;  30.10.14 kmf
;-----------------------------------------------------------------
begin
;-- set file name

  diri = "./"
  fili = "rectilinear_grid_2D.nc"

;-- open file and read variable
  f    =  addfile(diri+fili, "r")
  var  =  f->tsurf(0,:,:)

;-- define the workstation (plot type and name)
  wks = gsn_open_wks("png","plot_contour_lines_rect")

;-- set resources
  res =  True
  res@gsnMaximize           =  True            ;-- maximize graphics output

  res@cnFillOn              =  False           ;-- turn on contour fill
  res@cnLevelSelectionMode  = "ManualLevels"   ;-- set contour levels manually
  res@cnMinLevelValF        =  250.            ;-- minimum contour level
  res@cnMaxLevelValF        =  310.            ;-- maximum contour level
  res@cnLevelSpacingF       =  2               ;-- contour level spacing

  res@lbBoxMinorExtentF     =  0.15            ;-- decrease the height of the labelbar

  res@tiMainString          = "DKRZ - NCL Example: contour lines (rectilinear grid)" ;-- title string
  res@tiMainFontHeightF     =  0.02            ;-- title font size

;-- draw the contour map
  plot = gsn_csm_contour_map(wks, var, res)

end

Result: