Thanks Ben for your suggestion.
Adding *prj = TRUE *argument caused this error:
Error in ncdf4::ncvar_def(varname, varunit, list(xdim, ydim),
NAvalue(x), :
unused argument (prj = T)
Ahmed
On Tue, Feb 12, 2019 at 3:13 PM Ben Tupper <btup...@bigelow.org> wrote:
> Hi,
>
> Have you tried using the 'prj' argument to writeRaster? I don't know that
> it will be the solution, but according to ...
>
>
> https://www.rdocumentation.org/packages/raster/versions/2.8-19/topics/writeRaster
>
> It is documented among the '...' arguments. Setting prj = TRUE will cause
> the crs to be written to the file.
>
> Cheers,
> Ben
>
> On Feb 12, 2019, at 8:34 AM, Ahmed El-Gabbas <elgab...@gmail.com> wrote:
>
> Hello all,
>
> I am having a problem while converting a raster object as NetCDF (.nc)
> file, with keeping the CRS information in the output file.
> Here is a reproducible code:
>
> require(raster)
> require(ncdf4)
> CurrTemp <- tempfile()
> download.file(url =
> "https://seaice.uni-bremen.de/data/amsre/asi_daygrid_swath/s6250/2003/feb/Antarctic/asi-s6250-20030214-v5.hdf";,
> destfile = CurrTemp, mode = "wb", quiet = T)
> r <- raster(CurrTemp)
> r <- flip(r,2)
> extent(r) <- c(-3950000, 3950000, -3950000, 4350000)
> crs(r) <- "+proj=stere +lat_0=-90 +lat_ts=-70 +lon_0=0 +k=1 +x_0=0 +y_0=0
> +a=6378273 +b=6356889.449 +units=m +no_defs"
> r# class : RasterLayer # dimensions : 1328, 1264, 1678592 (nrow,
> ncol, ncell)# resolution : 6250, 6250 (x, y)# extent : -3950000,
> 3950000, -3950000, 4350000 (xmin, xmax, ymin, ymax)# coord. ref. :
> +proj=stere +lat_0=-90 +lat_ts=-70 +lon_0=0 +k=1 +x_0=0 +y_0=0 +a=6378273
> +b=6356889.449 +units=m +no_defs # data source : in memory# names :
> layer # values : 0, 100 (min, max)
>
> So far the raster object reads well, with CRS information included.
> However, when I try to save it as .nc file, R prints "coord. ref. : NA",
> and the produced file does not contain the CRS information.
>
> writeRaster(r, filename = "O:/Ahmed/r001.nc", varname="IceConc",
> overwrite=TRUE, format="CDF",
> xname="Longitude", yname="Latitude")# class : RasterLayer #
> dimensions : 1328, 1264, 1678592 (nrow, ncol, ncell)# resolution : 6250,
> 6250 (x, y)# extent : -3950000, 3950000, -3950000, 4350000 (xmin,
> xmax, ymin, ymax)# coord. ref. : NA # data source : O:/Ahmed/r001.nc # names
> : IceConc # zvar : IceConc
>
> raster("O:/Ahmed/r001.nc")# class : RasterLayer # dimensions : 1328,
> 1264, 1678592 (nrow, ncol, ncell)# resolution : 6250, 6250 (x, y)# extent
> : -3950000, 3950000, -3950000, 4350000 (xmin, xmax, ymin, ymax)# coord.
> ref. : NA # data source : O:/Ahmed/r001.nc # names : IceConc # zvar
> : IceConc
>
> Any solution?
>
> N.B. I also sent the same question at stackoverflow
> <https://stackoverflow.com/questions/54593552/saving-r-raster-to-netcdf-nc-file-with-keeping-crs-information>,
> without a solution so far.
>
> Thanks
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> *Dr. Ahmed El-Gabbas,*
> Ocean Acoustics Lab,
> Alfred-Wegener-Institut
> Helmholtz-Zentrum für Polar und Meeresforschung
> <image.png>
> My Website: https://elgabbas.github.io
> _______________________________________________
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>
>
> Ben Tupper
> Bigelow Laboratory for Ocean Sciences
> 60 Bigelow Drive, P.O. Box 380
> East Boothbay, Maine 04544
> http://www.bigelow.org
>
> Ecological Forecasting: https://eco.bigelow.org/
>
>
>
>
>
>
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