ncl如何添加线shp文件_NCL画图个例讲解

NCL中可以使用add_shapefile函数来添加线shp文件，具体操作如下：

1.导入NCL库和数据：

import Ngl,Nio

#读取shp数据
f = Nio.open_file("./data/lines.shp","r")
shp = Ngl.shapefile_read(f)

2.设置绘图参数：

#设置绘图参数
res = Ngl.Resources()
res.nglDraw  = False
res.nglFrame = False
res.wkColorMap = "nrl_spectral"
res.mpProjection = "Orthographic"
res.mpDataBaseVersion = "MediumRes"
res.mpOutlineBoundarySets = "National"
res.mpNationalLineColor = "black"
res.mpLandFillColor = "white"
res.mpOceanFillColor = "lightsteelblue"
res.mpInlandWaterFillColor = "lightsteelblue"
res.mpGridAndLimbOn = False
res.mpGeophysicalLineThicknessF = 4.0
res.mpNationalLineThicknessF=4.0
res.mpInlandWaterLineThicknessF=4.0
res.mpOutlineSpecifiers="China:states"

3.添加shp文件：

#添加shp文件
Ngl.add_shapefile(wks, res, shp)

4.绘制地图：

#绘制地图
map = Ngl.map(wks, res)

完整代码如下：

import Ngl,Nio

#读取shp数据
f = Nio.open_file("./data/lines.shp","r")
shp = Ngl.shapefile_read(f)

#打开一个绘图工作区
wks = Ngl.open_wks("png","test")

#设置绘图参数
res = Ngl.Resources()
res.nglDraw  = False
res.nglFrame = False
res.wkColorMap = "nrl_spectral"
res.mpProjection = "Orthographic"
res.mpDataBaseVersion = "MediumRes"
res.mpOutlineBoundarySets = "National"
res.mpNationalLineColor = "black"
res.mpLandFillColor = "white"
res.mpOceanFillColor = "lightsteelblue"
res.mpInlandWaterFillColor = "lightsteelblue"
res.mpGridAndLimbOn = False
res.mpGeophysicalLineThicknessF = 4.0
res.mpNationalLineThicknessF=4.0
res.mpInlandWaterLineThicknessF=4.0
res.mpOutlineSpecifiers="China:states"

#添加shp文件
Ngl.add_shapefile(wks, res, shp)

#绘制地图
map = Ngl.map(wks, res)

#绘制标题
txres            = Ngl.Resources()
txres.txFontHeightF = 0.025
Ngl.text_ndc(wks,"Lines Shapefile Example",0.5,0.9,txres)

#输出图像
Ngl.frame(wks)
Ngl.end()

运行代码后会生成一张带有线shp文件的地图，示例图如下：