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

[Matthew Knepley]

On Fri, Jun 4, 2021 at 10:59 AM Peder Jørgensgaard Olesen <pjool at mek.dtu.dk>
wrote:

> Excellent question. It may well be some quirk of my own setup that
> somehow makes VecView run rather sluggishly, making it
> hardly relevant to the general case.
>
Maybe I can help speed things up for you. Is this in serial or parallel? Is
the vector big or small? Is it possible to send the output of -log_view?

  Thanks

     Matt

> - Peder
> ------------------------------
> *Fra:* Matthew Knepley <knepley at gmail.com>
> *Sendt:* 4. juni 2021 16:48:05
> *Til:* Peder Jørgensgaard Olesen
> *Cc:* Jose E. Roman; petsc-users at mcs.anl.gov
> *Emne:* Re: [petsc-users] SLEPc: HDF5 support for SVD/EPSValuesView?
>
> 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/>
>


-- 
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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