r - 如何从netcdf文件可视化 map ？

我有一个netcdf文件，我只想可视化土壤深度图

   [1] "file C:\\Users\\SoilDepth-gswp.nc has 3 dimensions:"
     [1] "x   Size: 360"
     [1] "y   Size: 150"
     [1] "land   Size: 15238"
     [1] "------------------------"
     [1] "file C:\\SoilDepth-gswp.nc has 3 variables:"
     [1] "float nav_lon[x,y]  Longname:Longitude Missval:1e+30"
     [1] "float nav_lat[x,y]  Longname:Latitude Missval:1e+30"
     [1] "float SoilDepth[land]  Longname:Soil depth Missval:1.00000002004088e+20"

似乎我必须将纬度和经度以及陆地点联系起来才能获得土壤深度的 map 。我真的很困惑。任何人都可以通过这种数据来帮助我。

最佳答案

library(ncdf)
# I'm assuming this is the netcdf file you are working with:
download.file("http://dods.ipsl.jussieu.fr/gswp/Fixed/SoilDepth.nc", destfile="SoilDepth.nc")
soil <- open.ncdf("SoilDepth.nc")
#The way to extract a variable is as following:
soil$var[[3]] -> var3 # here, as shown in your question, SoilDepth is the 3rd variable
get.var.ncdf(soil, var3) -> SoilDepth

dim(SoilDepth)
[1] 15238

就像在您的netcdf文件的摘要中所说的那样，变量SoilDepth仅取决于维度land，而不取决于x和y，因此，我不确定在绘制此数据集时会离开哪里。

编辑

事实证明，有一个链接x，y和land的键:

download.file("http://dods.ipsl.jussieu.fr/gswp/Fixed/landmask_gswp.nc", destfile="landmask.nc")
landmask <- open.ncdf("landmask.nc")
landmask$var[[3]] -> varland
get.var.ncdf(landmask, varland) -> land
sum(land==1)
[1] 15238

因此，为了绘制:

# The values where stored in an expected order, hence the transpose
land = t(land)
land[land==1] <- SoilDepth
land[land==0] <- NA
land = t(land)
image(land)

关于r - 如何从netcdf文件可视化 map ？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/12285120/

netCDF文件

r - 如何从netcdf文件可视化 map ？