On Fri, Feb 20, 2015 at 11:46 PM, Barry Smith <[email protected]> wrote:
>
> Mark,
>
> What's the rational for keeping the Chebyshev tuning inside GAMG that
> duplicates that is already support by KSPChebyshev ? I'd like to remove
> this chunk of code from GAMG since it is duplicative and instead make sure
> that the Chebyshev tuning inside the KSPChebyshev provides everything that
> is needed.
>
> Also in particular what about the /* zeroing out BC rows -- needed for
> crazy matrices */ should this be ported to KSPChebyshev ?
>
This is a fix for a matrix that has a norm << X, but X is put on the
diagonal for BCs. You then get X as the eigen estimate. We should
probably remove this ...
>
> /* create cheby smoothers */
> for (lidx = 1, level = pc_gamg->Nlevels-2; lidx <= fine_level; lidx++,
> level--) {
> KSP smoother;
> PetscBool flag,flag2;
> PC subpc;
>
> ierr = PCMGGetSmoother(pc, lidx, &smoother);CHKERRQ(ierr);
> ierr = KSPGetPC(smoother, &subpc);CHKERRQ(ierr);
>
> /* do my own cheby */
>
> Thanks
>
> Barry
>
>
>
