Charlie Zender <zender@xxxxxxx> writes:
> Hi and happy new year to the netCDF group,
>
> Will netCDF4 make bit-for-bit (BFB) reproducible files?
> In other words will running a determinstic model twice on the same
> machine (without changing compiler, netCDF library, etc.) produce
> identical output files?
> I thought that netCDF4 would, like netCDF3, use deterministic
> algorithms without any date-stamps within the file, and thus produce
> BFB files. Apparently I am wrong.
>
> To determine whether files were BFB I checked their SHA1 sums.
> netCDF3 produces BFB files and netCDF4 (snapshot) does not (below).
> BFB output files make models easier to debug, so it would be helpful
> if netCDF4 continued the netCDF3 BFB "tradition". Is this possible?
> Am I missing something? Is HDF5 the culprit?
>
> Thanks,
> Charlie
>
Howdy Charlie!
I is my understanding that HDF5 does not guarantee the bit-or-bit
reproducibility of their files. I have forwarded this to them to
confirm this...
I'm afraid there is nothing I can do at the netCDF-4 level to change
that.
Thanks,
Ed
--
Ed Hartnett -- ed@xxxxxxxxxxxxxxxx
