[gdal-dev] Creating NetCDF dataset with sub datasets

[Even Rouault]

Pierre,

Le 12/03/2024 à 12:51, Pierre Chatelier a écrit :
> Ok, I can confirm that
> -creating a dataset with <n> bands with the netCDF driver works
> -saving the dataset will write the expected "SUBDATASETS" domain with 
> "SUBDATASET_<i>_NAME=NETCDF:"<file>":"<band name>"
>
> But I can't figure out how to customize the <band name>, which is 
> Band1, Band2, Band3...
> I tried GDALRasterBand::SetDescription(), but without success

Looking at netcdfdataset.cpp line 9625, the netCDF variable name for a 
band is extracted from the NETCDF_VARNAME band metadata item of the 
source band.

>
> Also, is there a reason why AddBand() is not supported by the netCDF 
> driver ? I expected it to be able to add bands on demand as new 
> "netcdf variables".
>
I guess that could be implemented. There would be a subtlety however:

- if CreateCopy() has been invoked with NETCDF_DIM_EXTRA_xxx, 
NETCDF_DIM_xxx_DEF metadata items, to ask for bands to be modeled as a 
dimension (for example the time dimension of a 3D variable), that would 
require the band dimension to be created as UNLIMITED however at dataset 
creation.

- otherwise for 2D variables, yes, implementing AddBand() should be 
relatively straighforward ... hopefully ... (please don't sue me, if it 
is not. The netCDF driver has its peculiarities...)

Even

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