[petsc-users] SLEPc: HDF5 support for SVD/EPSValuesView?

[Matthew Knepley]

On Fri, Jun 4, 2021 at 10:28 AM Peder Jørgensgaard Olesen <pjool at mek.dtu.dk>
wrote:

> What Matt suggests could perhaps be used as a workaround, though it
> appears neither elegant nor in my experience efficient. I may be wrong on
> this.
>
Why is it not efficient?

  Thanks,

     Matt

> My attempted solution was to use a binary viewer instead, but I can't
> find a clear way to retrieve values thus stored with PETSc, as these do not
> lend themselves to be read using VecLoad. Again one might go about that
> by wrapping them inside a vector and send that to the viewer, which just
> brings us back around to the original problem.
>
>
> - Peder
> ------------------------------
> *Fra:* Jose E. Roman <jroman at dsic.upv.es>
> *Sendt:* 4. juni 2021 16:01:04
> *Til:* Matthew Knepley
> *Cc:* Peder Jørgensgaard Olesen; petsc-users at mcs.anl.gov
> *Emne:* Re: [petsc-users] SLEPc: HDF5 support for SVD/EPSValuesView?
>
> The problem is that here I am writing PetscReal's not PetscScalar's, and
> in EPS I am writing PetscComplex even in real scalars. That is why I did
> not implement it as you are suggesting.
>
> Jose
>
>
> > El 4 jun 2021, a las 15:56, Matthew Knepley <knepley at gmail.com>
> escribió:
> >
> > On Fri, Jun 4, 2021 at 9:31 AM Jose E. Roman <jroman at dsic.upv.es> wrote:
> > I could try and adapt the HDF5 code in PETSc for this, but I am no HDF5
> expert. Furthermore I am busy at the moment, so it is faster if you could
> prepare a merge request with this addition.
> >
> > I think the easiest thing is to wrap a Vec around the values and just
> VecView() it into the same HDF5 file.
> >
> >   THanks,
> >
> >     Matt
> >
> > Jose
> >
> >
> > > El 4 jun 2021, a las 13:10, Peder Jørgensgaard Olesen via petsc-users <
> petsc-users at mcs.anl.gov> escribió:
> > >
> > > Hello
> > >
> > > In SLEPc one may write singular vectors to an HDF5 file using
> SVDVectorsView(), but a similar option doesn't seem to work for singular
> values using SVDValuesView(). The values are viewed correctly using other
> viewers, but nothing is seemingly produced when using an HDF5 viewer.
> Looking at the source code seems to confirm this, and suggests that there
> is a similar situation with EPS.
> > >
> > > Is this correct, and if so, might there be plans to include such
> functionality in future releases?
> > >
> > > Med venlig hilsen / Best Regards
> > >
> > > Peder Jørgensgaard Olesen
> > > PhD Student, Turbulence Research Lab
> > > Dept. of Mechanical Engineering
> > > Technical University of Denmark
> > > Koppels Allé
> > > Bygning 403, Rum 105
> > > DK-2800 Kgs. Lyngby
> >
> >
> >
> > --
> > What most experimenters take for granted before they begin their
> experiments is infinitely more interesting than any results to which their
> experiments lead.
> > -- Norbert Wiener
> >
> > https://www.cse.buffalo.edu/~knepley/
>
>

-- 
What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which their
experiments lead.
-- Norbert Wiener

https://www.cse.buffalo.edu/~knepley/ <http://www.cse.buffalo.edu/~knepley/>
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