On Sat, Jun 9, 2012 at 6:43 PM, Mark F. Adams <mark.adams at columbia.edu>wrote:
> 1) I need a G-S kernel that takes an IS of indices to process and a flag > to process them in forward or reverse order. How should I proceed to do > this. Should I just clone sor? > You are going to have several of these index sets? You could have a PCSORSetIS(). Probably need to add a MatOp for MatSORIS(). Barry might have other ideas. > 2) I don't want to use Richardson iterations for G-S. Should I make a G-S > KPS method? I don't want to take a residual in the iterator (KSP) and if > symmetric G-S is requested then it should drive this I think. > Look at PCApplyRichardson_SOR(). > SOR does two sweeps in each application; I'm not wild about that because > a good way to run G-S in a V(1,1) cycle is to do a forward sweep in pre > smoothing and a backward sweep in post smoothing. > Well, MatSOR() has this flag MatSORType that can specify forward and reverse. You have one PC for the down-smoother and another for the up-smoother, then configure one to be a forward sweep and the other to be reverse. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20120609/13b5956c/attachment.html>
