writeRaster - netcdf - Rotation

Hi Robert and Pascal,

thanks for the tips, but my problem isn't completely solved. The explicit
laebling of x and y works, but doesn't change the rotation.
I followed Pascals hint:
My raster*-Object has the dimensons: "220 171 x".
When I export this raster*-Obejct as posted below as nc-file and reimport
it with the ncdf-Package, the dimensions are: "171 220 x". The explicit
labeling doesn't change that. The first dimension is always 171 in the
nc-file, no matter if its names 'easting' or 'northing'. To me it looks
like raster and ncdf interpret x and y differently?!

Beste regards
Philipp


Philipp,

You are right, the labels easting and northing are reversed. I will fix
that. You can set them yourself as illustrated below:

library(raster)
tmp<- raster(nr=5, nc=10,crs='+proj=utm +zone=12')
tmp[] <- 1:ncell(tmp)
writeRaster(tmp, filename='export.nc', format="CDF", overwrite=TRUE,
xname='easting', yname='northing')
raster('export.nc')

nc <- open.ncdf("export.nc")
get.var.ncdf(nc,"easting")

Robert

On Fri, Mar 22, 2013 at 7:17 AM, <amock at gmx.li> wrote:

Hey there,
I?ve got a problem concerning exporting a raster*-Object as nc-File:
When exporting rasterLayers or rasterBricks as nc-Files with writeRaster
from the raster-Package, easting and northing in the resulting nc-File

are

switched, which results in a rotated plot. I can correct this afterwards,
but it should be possible to be correct right away?!

Example code for a rasterLayer:
tmp <- raster(readGDAL(?example.asc?,p4s="+init=epsg:31467"))
writeRaster(tmp, filename=?export.nc?, format="CDF", overwrite=TRUE)
nc <- open.ncdf("export.nc")
x <- get.var.ncdf(nc,?easting?)
y <- get.var.ncdf(nc,?northing?)

R version 2.15.3 (2013-03-01)
Platform: x86_64-w64-mingw32/x64 (64-bit)
ncdf_1.6.6 raster_2.1-16 rgdal_0.8-5 sp_1.0-6

I hope someone can give me a hint! Thanks in advance!
Philipp