[petsc-users] PCSHELL

[Su Yan]

I do not think they take the reordering as an input.I will need to reorder
it myself and then pass it to the ILUT subroutine.


On Thu, Jul 25, 2013 at 4:08 PM, Barry Smith <bsmith at mcs.anl.gov> wrote:

>
> On Jul 25, 2013, at 4:04 PM, Su Yan <suyan0 at gmail.com> wrote:
>
> > Thanks, Barry.
> >
> > I have interfaced PETSc with MKL ILUT preconditioner through PCSHELL,
>
>    Does MKL ILUT take a reordering (that is a permutation of the set
> {0,1,2,….n-1} as an input argument? Or do they want you to reorder the
> matrix in the new ordering explicitly and pass that new matrix into the MKL
> routine?
>
>    Barry
>
> > but want to use reordering technique comes with the PETSc package.
> Probably I can do it by extracting the reordering matrices, but the system
> matrix is the Jacobian set by SNESSetJacobian() and solved by KSP. Since
> the Jacobian matrix is changing for different Newton steps, I am strill
> trying to figure out how to implement the reordering my self.
> >
> > Best,
> > Su
> >
> >
> > On Thu, Jul 25, 2013 at 3:09 PM, Barry Smith <bsmith at mcs.anl.gov> wrote:
> >
> > On Jul 25, 2013, at 12:01 PM, Su Yan <suyan0 at gmail.com> wrote:
> >
> > > Hi, can I use PCSetType(myPC, PCSHELL); together with
> PCFactorSetMatOrderingType(myPC, MATORDERINGRCM)?
> >
> >    PCFactorSetMatOrdering() is only effective if the PC is a subclass of
> PCFactor, for example PCLU is a subclass of PCFactor as are PCILU and
> PCCHOLESKY and PCICC
> >
> >    If you want to use things like this you cannot use PCSHELL (which is
> a subclass of only the basic PC) you can copy the code for PCCreate_LU()
> for example and modify it for what you want to do.  Or you can register new
> factorization and solver package as a MatSolverPackage; see for example
> superlu.c in mat/impls/aij/seq/superlu/
> >
> >    What is it you want to do?
> >
> >    Barry
> >
> >
> > >
> > > Will the reordering still take effect?
> > >
> > > Thanks,
> > > Su
> > >
> >
> >
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20130725/39a0bc8f/attachment.html>