[petsc-users] Block-ILU in Petsc

[behzad baghapour]

Thanks. Having a robust VBILU is a rather hard work while the new
regenerated local blocks may or may not have proper spectral properties and
may cause instabilities in iteration process but it would be a
problem-dependent issue I think...

On Fri, Oct 14, 2011 at 5:51 PM, Barry Smith <bsmith at mcs.anl.gov> wrote:

>
> On Oct 14, 2011, at 9:09 AM, behzad baghapour wrote:
>
> > So, Am I right with 2 things below?
> >
> > 1- If I set BAIJ for Mat, then the ILU preconditoner automatically
> recognize to use Block-version of ILU preconditioners? (like VBILUM
> developed by Saad and coworkers) or I should do more for Block
> preconditioning?
> >
> > 2- "the block size is the same the matrix block size" means that there is
> no way to combine the matrix elements to build blocks of possible maximum
> size like Hash method or something like this?
>
>    No. Though we would love to accept a contribution of a robust dynamic
> variable block size ILU from users.
>
>   Barry
>
> >
> > Thanks a lot.
> >
> >
> >
> > On Fri, Oct 14, 2011 at 1:50 PM, Matthew Knepley <knepley at gmail.com>
> wrote:
> > On Fri, Oct 14, 2011 at 3:05 AM, behzad baghapour <
> behzad.baghapour at gmail.com> wrote:
> > Dear all,
> >
> > How should I efficiently use block-ILU preconditioner in Petsc?
> >
> > I saw in man-page of PCILU:
> > "For BAIJ matrices this implements a point block ILU". What exactly it
> means?
> >
> > That the block size is the same the matrix block size.
> >
> >   Matt
> >
> > Regards,
> > Behzad
> >
> >
> >
> >
> >
> > --
> > 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
> >
> >
> >
> > --
> > ==================================
> > Behzad Baghapour
> > Ph.D. Candidate, Mechecanical Engineering
> > University of Tehran, Tehran, Iran
> > https://sites.google.com/site/behzadbaghapour
> > Fax: 0098-21-88020741
> > ==================================
> >
>
>


-- 
==================================
Behzad Baghapour
Ph.D. Candidate, Mechecanical Engineering
University of Tehran, Tehran, Iran
https://sites.google.com/site/behzadbaghapour
Fax: 0098-21-88020741
==================================
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