Preconditioner for bicg

[Barry Smith]

[bsmith:~] bsmith% cd Src/petsc-dev/src/ksp/ksp/impls
[bsmith:ksp/ksp/impls] bsmith% grep ApplyTranspose */*.c
bicg/bicg.c:  ierr = KSP_PCApplyTranspose(ksp,Rl,Zl);CHKERRQ(ierr);
bicg/bicg.c:       ierr = KSP_PCApplyTranspose(ksp,Rl,Zl);CHKERRQ(ierr);
bicg/bicg.c:       ierr = KSP_PCApplyTranspose(ksp,Rl,Zl);CHKERRQ(ierr);

[bsmith:ksp/ksp/impls] bsmith% grep ApplyTranspose */*/*.c
cg/cgne/cgne.c:  ierr = PCApplyTransposeExists(ksp->pc,&transpose_pc);CHKERRQ(ierr);
cg/cgne/cgne.c:    ierr = KSP_PCApplyTranspose(ksp,T,Z);CHKERRQ(ierr);
cg/cgne/cgne.c:  ierr = KSP_PCApplyTranspose(ksp,T,Z);CHKERRQ(ierr);

  These are the two methods that require the transpose operation.

  I have documented both of their manual pages to indicate this.

   Barry


On Thu, 11 Oct 2007, Keita Teranishi wrote:

> Hi Barry,
> 
> Could you suggest any other KSP solvers that have the same type of problems?
> 
> Thanks,
> ================================
>  Keita Teranishi
>  Math Software Group
>  Cray Inc.
>  keita at cray.com
> ================================
> 
> -----Original Message-----
> From: owner-petsc-users at mcs.anl.gov [mailto:owner-petsc-users at mcs.anl.gov] On Behalf Of Barry Smith
> Sent: Thursday, October 11, 2007 4:50 PM
> To: petsc-users at mcs.anl.gov
> Subject: Re: Preconditioner for bicg 
> 
> 
>   For some preconditioners it is simply not easily possible to apply the 
> transpose of the preconditioner. Even multigrid requires some work to do this.
> 
>    Barry
> 
> 
> On Thu, 11 Oct 2007, Keita Teranishi wrote:
> 
> > Hi,
> > 
> >  
> > 
> > I'd like to make sure preconditioners supported for bicg. I found bicg only accepts preconditioners that is interfaced through PCApplyTranspose.
> > 
> > For this reason, I see several preconditioners fails with bicg.
> > 
> >  
> > 
> > Thanks,
> > 
> > ================================
> >  Keita Teranishi
> >  Math Software Group
> >  Cray Inc.
> >  keita at cray.com
> > ================================ 
> > 
> >  
> > 
> > 
> 
>