[petsc-users] HDF5 timestepping in PETSc 3.16

[Jeremy Theler]

On Thu, 2021-10-21 at 13:04 -0400, Matthew Knepley wrote:
> On Tue, Oct 19, 2021 at 6:12 AM Matthew Knepley <knepley at gmail.com>
> wrote:
> > On Mon, Oct 18, 2021 at 10:35 PM Adrian Croucher
> > <a.croucher at auckland.ac.nz> wrote:
> > > Any response on this?
> > > 
> > > This is a bit of a showstopper for me - I can't upgrade to PETSc
> > > 3.16 if 
> > > it does not allow my users to read their HDF5 files created using
> > > earlier versions of PETSc.
> > > 
> > > So far I can't see a workaround. Possibly the timestepping
> > > functions 
> > > need some kind of optional parameter to specify what the default 
> > > timestepping attribute should be, if it's not present in the file
> > 
> > I think you are right. We should always write the attribute, but
> > have it be false. We should
> > interpret a missing attribute as an old file.
> > 
> Okay, I think I have it. Can you look at this branch?
> 
>   https://gitlab.com/petsc/petsc/-/merge_requests/4483
> 
> There is now an option that lets you set the default timestepping
> behavior
> 
>   -viewer_hdf5_default_timestepping
> 
> I think that is what you want.

I'd like to rely on PetscViewerHDF5SetDefaultTimestepping() to provide
backwards compatibility as well. This branch has been merged into
master back in November but never made it to the stable v3.16 releases.

Can you guys check please?


Thanks
--
jeremy theler
www.seamplex.com