Example 2 - contour plots

load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"

begin

  cdf_file = addfile("$NCARG_ROOT/lib/ncarg/data/cdf/contour.cdf","r")

  temp = cdf_file->T(0,0,:,:)               ; 变量temperature
  Z    = cdf_file->Z(0,0,:,:)               ; 变量geopotential height
  pres = cdf_file->Psl(0,:,:)               ; 变量pressure at mean sea level
  lat  = cdf_file->lat                      ; 变量latitude
  lon  = cdf_file->lon                      ; 变量longitude

  temp = temp - 273.15                      ; 温度转换 Kelvin -> Celsius
  pres = pres * 0.01                        ; 气压转换 Pa -> mb
  temp@units = "(C)"                        ; 改变单位
  pres@units = "(mb)"                       ; 改变单位

  xwks = gsn_open_wks("x11","gsun02n")      ; 打开x11的工作空间.

  plot = gsn_contour(xwks,temp,False)       ; 绘制一个等值线图

;----------- Begin second plot -----------------------------------------

  resources                 = True       ; 资源设置

  resources@cnMonoLineColor = False      ; 关闭绘制一种颜色的方案

  resources@tiMainString    = "Temperature (C)"  ; 标题

  plot = gsn_contour(xwks,temp,resources)  ; 绘制等值线图

;----------- Begin third plot -----------------------------------------

  resources@cnFillOn          = True        ; 打开等值线图填充
  resources@cnMonoFillPattern = False       ; 关闭等值线图单线填充
  resources@cnMonoFillColor   = True
  resources@cnMonoLineColor   = True

  resources@tiXAxisString    = lon@long_name
  resources@tiYAxisString    = lat@long_name
  resources@sfXArray         = lon
  resources@sfYArray         = lat

  plot = gsn_contour(xwks,temp,resources)   ; 绘制等值线图

;---------- Begin fourth plot ------------------------------------------

  resources@cnMonoFillPattern     = True     ; 使用solid填充
  resources@cnMonoFillColor       = False    ; 使用复杂颜色
  resources@cnLineLabelsOn        = False    ; 线条标签
  resources@cnInfoLabelOn         = False    ; 信息标签
  resources@cnLinesOn             = False    ; 等值线

  resources@pmLabelBarDisplayMode = "Always" ; 工具栏
  resources@lbPerimOn             = False    ; 关闭周长

  resources@tiMainString    = Z@long_name
  resources@tiMainFont      = 26
  resources@tiXAxisFont     = 26
  resources@tiYAxisFont     = 26

  plot = gsn_contour(xwks,Z,resources)    ; 绘制等值线图

;---------- Begin fifth plot ------------------------------------------

  cmap = (/(/0.,0.,0./),(/1.,1.,1./),(/.1,.1,.1/),(/.15,.15,.15/),\
         (/.2,.2,.2/),(/.25,.25,.25/),(/.3,.3,.3/),(/.35,.35,.35/),\
         (/.4,.4,.4/),(/.45,.45,.45/),(/.5,.5,.5/),(/.55,.55,.55/),\
         (/.6,.6,.6/),(/.65,.65,.65/),(/.7,.7,.7/),(/.75,.75,.75/),\
         (/.8,.8,.8/),(/.85,.85,.85/)/)

  gsn_define_colormap(xwks,cmap)          ; 定义一个新的颜色map

  resources@tiMainString    = pres@long_name

  plot = gsn_contour(xwks,pres,resources) ; 绘制一个等值线图

  print(temp(2:5,7:9))             ;输出temp变量

  print(temp!0)                    ; 输出temp的一维名称
  print(temp!1)                    ; 输出temp的二维名称
  print(temp@long_name)            ; 输出属性long_name和units
  print(temp@units)
  print(temp&lat)                  ; 输出变量lat
  print(temp&lon)                  ; 输出变量lon

  ascii_file = "data.asc"                 ;创建ASC11文件名
  system("/bin/rm -f " + ascii_file)      ; 移除asc11文件
  asciiwrite(ascii_file,temp(7:3:2,0:4))  ; 写入ASC11
  delete(plot)       ;清除
  delete(temp)
  delete(resources)
end