Many thanks to Wei-keng Liao for finding the cause of the missing data. There
is a bug in dfile.c where netcdf does not recognize NC_PNETCDF in the cmode
when opening a file for writing. (In 4.3.1.1, it is at line 1675 in dfile.c)
The test code with netcdf-fortran works because it writes data after the
enddef, but before closing the file.
- Ted
Begin forwarded message:
> I think I found the cause !
>
> One question first. Does your code first creates a new nc file, defines
> dimensions, variables, put attributes, close the file without calling
> any put_var? And then reopen the file and call many get_var and put_var?
>
Yes, it does.
> If this is the case, then the cause is due to a bug in netCDF I reported
> to netCDF team recently. See
> https://bugtracking.unidata.ucar.edu/browse/NCF-319
>
> A simple fix is to add the 3 lines (1712-1715 below) after line 1711 of file
> libdispatch/dfile.c.
> 1710 else if(cmode & NC_NETCDF4) model |= NC_DISPATCH_NC4;
> 1711 }
> 1712 else if (model == NC_DISPATCH_NC3) {
> 1713 /* if file is a CDF-1 or CDF-2, and PnetCDF method is selected */
> 1714 if (cmode & NC_PNETCDF) model = NC_DISPATCH_NC5;
> 1715 }
>
> Without this fix, netCDF will fail to call PnetCDF APIs even if NF90_PNETCDF
> open mode is used. It will use POSIX read/write instead. Please re-build your
> netCDF and let me know if it works.
>
> Wei-keng
>
It works!!!
