You do not specify whether you have compiled with hdf5 and zlib?
If you haven't specified this at compile time, you don't have compression
enabled and you need to install hdf5 and zlib (at least).
You can test your file by this:
ncdump -k <file>
'1' or 'classic' => netcdf classic format
'2', '64-bit-offset', or '64-bit offset' => netCDF 64-bit format
'3', 'hdf5', 'netCDF-4', or 'enhanced' => netCDF-4 format (enhanced data
model)
'4', 'hdf5-nc3', 'netCDF-4 classic model', or 'enhanced-nc3' => netCDF-4
classic
model format
What you want is 3 or 4 (as I remember, a netcdf3 installation from a
netcdf4 source would only allow k=1 or k=2).
Kind regards Nick
2013/12/17 Frank Fuchs <fk.fuchs@xxxxxxxxxxxxxx>
> Hi,
>
> I managed to compile netcdf-4.3.0 using mingw-w64 gcc 4.8.1.
> All I had to disabale was DAP (I have no use for anyway).
>
> I tested that I can read and write netcdf files using the newly build .dll
> Now I wanted to test compression using the cxx4 interface, enabling it by
> ncvar_data.setCompression(true,true,1) for the heaviest of my variables.
>
> However, even for a file filled with constants the files remain as big as
> before.
> Further tests using nccopy -d9 old.nca new.nca did not result in a
> modification of the file size.
>
> Any advise?
>
> Best,
> Frank
>
>
>
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--
Kind regards Nick
