cdo and netcdf
Added by Graziano Giuliani over 11 years ago
Hi,
I have found a strange behaviour of cdo using netcdf 4 file format. I am trying to interpolate a global grid to a projected grid, and have files generated by different codes in different formats:
reg_grid.nc : netCDF3 format
glob_grid.nc : netCDF4 format compressed
datafile.nc : netCDF4 format compressed
the below command fails:
cdo gencon,reg_grid.nc -setgrid,glob_grid.nc datafile.nc remapweights.nc
cdo gencon (Abort): Unsupported grid type: generic
If all files are in netcdf3, the same command works without any problem:
nccopy -k 1 glob_grid.nc tmp.nc && mv tmp.nc glob_grid.nc
nccopy -k 1 datafile.nc tmp.nc && mv datafile.nc tmp.nc
cdo gencon,reg_grid.nc -setgrid,glob_grid.nc datafile.nc remapweights.nc
cdo(2) setgrid: Processed 65318400 values from 1 variable over 252 timesteps ( 22.82s )
cdo gencon: Processed 259200 values from 1 variable over 1 timestep ( 22.82s )
it seems cdo doesn't like mixed netcdf formats (?), but it is a shame as datafile in non compressed format in my case is almost 4 times as big as the HDF5 compressed netCDF4, and going with nccopy takes ages.
Replies (4)
RE: cdo and netcdf - Added by Uwe Schulzweida over 11 years ago
Hi Graziano,
Mixed netCDF formats shouldn't be a problem in CDO. Could you please attach the files reg_grid.nc and glob_grid.nc?
We don't need all 252 timesteps, the first 4 should be enough. You can select the timesteps with the NCO tool ncks:
ncks -d time,0,3 ifile ofile
Cheers,
Uwe
RE: cdo and netcdf - Added by Graziano Giuliani over 11 years ago
Here comes the data. In the archive you have two directories, work and nowork, with the above test cases.
| test.tar.gz (1.39 MB) test.tar.gz | netCDF4 - netCDF3 mixed files problem |
RE: cdo and netcdf - Added by Graziano Giuliani over 11 years ago
Sorry, the command above should now read:
cdo gencon,REGCM_grid.nc -setgrid,CMIP5_grid.nc HIST_ACET.nc remapweights.nc
RE: cdo and netcdf - Added by Uwe Schulzweida over 11 years ago
Hi Graziano,
Thanks for the data! The CMIP5_grid.nc file contains a SCRIP formatted grid description. This format is supported in CDO only for netCDF3. I have implemented the netCDF4 support for the SCRIP format in the next CDO release.
Best regards,
Uwe