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[netCDF #FCH-479977]: Building netcdf c++ legacy library netcdf-cxx-4.2

Hi Mike,

> We are some questions about how to build the legacy C++ library for
> netCDF-4 support.
> 
> We are using netcdf-cxx-4.2.
> 
> Previously, when we built version 4.1.3 (all in one), we ran configure
> as follows:
> 
> ./configure --prefix=/tmp/ncf --enable-netcdf-4 --disable-dap
> 
> For building netcdf-cxx-4.2, --enable-netcdf-4 does not seem to apply.
> The only way I have been able to get it to support netCDF-4 and
> compression is to use:
> 
> setenv CPPFLAGS "-g -I/tmp/ncf/include -DUSE_NETCDF4"
> ./configure --prefix=/tmp/ncf
> 
> Is this the correct way to do this, or do you have a cleaner option?

Even doing it that way won't support compression, unless you are actually
calling C functions to set variable deflation levels.  The legacy C++ API
provides almost no support for netCDF-4, beyond specifying a mode for
creating a netCDF-4 file in the NcFile constructor.

If you need the per-variable compression supported by the netCDF-4 C or 
Fortran interfaces with real C++, you'll have to switch to the contributed
C++ netCDF-4 API.  It's methods for specifying deflation are documented here:

  
http://www.unidata.ucar.edu/software/netcdf/docs/cxx4/classnetCDF_1_1NcVar.html

under the NcVar::setCompression and NcVar::getCompression methods.

However, as you probably know, the contributed C++ netCDF-4 is not backward
compatible with the old legacy C++ API, so it may require quite a bit of 
rewriting.

As far as building the legacy C++ library, this worked for me, after installing 
the
netCDF-4 C library under /usr/local:

  LD_LIBRARY_PATH=/usr/local/lib CPPFLAGS="-I/usr/local/include -DUSE_NETCDF4" 
./configure --enable-netcdf-4
  make -j check

In particular, I didn't have to disable DAP.

--Russ


  
Russ Rew                                         UCAR Unidata Program
address@hidden                      http://www.unidata.ucar.edu



Ticket Details
===================
Ticket ID: FCH-479977
Department: Support netCDF
Priority: Normal
Status: Closed