Re: 991222: netcdf on O2K vs Cray j90

> Date: Wed, 22 Dec 1999 13:15:34 -0700 (MST)
> From: Ben Foster <address@hidden>
> To: address@hidden
> Subject: Re: 991222: netcdf on O2K vs Cray j90
> Organization: HAO
> Keywords: 199912222016.NAA02244

Hi Ben,

> Another question. If I should direct these (I suspect
> minor) questions elsewhere, please let me know.

If you send them to "address@hidden", they'll be directed to
someone who can handle them, even if I happen to be away from my email
or on vacation.

> I need to write 8-byte reals to netcdf output files
> from both SGI and Cray machines. On the Cray j90 ouray
> I call nf_def_var(..NF_FLOAT..) and nf_put_var_real(..), 
> and everything is fine. Ncdump shows good numbers using
> same file on both machines.

Presumably your 8-byte reals are only stored externally in the netCDF
file as 4-byte reals though, since you defined the external type of
the variable to be NF_FLOAT.

> On the SGI (say o2k utefe), I compile with -r8 for 8-byte 
> reals, and use the same nf_def_var and nf_put_var_real
> calls. But when I run ncdump from either platform on the 
> file written from the SGI, the reals are incorrect. The
> source code types are all "real".
> 
> I would like to avoid calling nf_def_var and nf_put_var_xx
> with different types (e.g., NF_FLOAT on Cray, NF_DOUBLE on 
> SGI). I am linking /usr/local/lib32/r4i4 on utefe (and 
> -I/usr/local/include). Is this the wrong lib? Thanks,

I think the problem is in trying to link your code, compiled with the
-r8 option with a netCDF library compiled without the -r8 option.  If
you rebuild the netcdf library with the -r8 option and link against
that, things should work fine.  I believe this is not just a netCDF
problem.  I suspect you will encounter similar problems whenever you try
to link an object file compiled with the -r8 option with a library
compiled without the -r8 option, and vice versa.

--Russ

_____________________________________________________________________

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