On Dec 21, 2010, at 2:21 PM, Jed Brown wrote: > On Tue, Dec 21, 2010 at 14:42, Jan Biermann <bierm...@tu-harburg.de> wrote: > first, I sent the stuff to Petsc and they want to include it (otherwise it > would not make any sense to make the changes in libmesh I guess). > > Okay, I asked because I hadn't seen it go by and it's not in the petsc-dev > repository yet. > > to answer Jed's question (Why is a special interface needed from libmesh?) > There are certain petsc functions that need to be included additionally but > most important, I chose to handle the recycle space (that will be reused from > one solve to the other) at the linear implicit system, so outside from petsc. > This way it is easier to switch between solvers etc. without reallocating > memory and the recycle space is easier to manipulate (there is a lot of > freedom and potential for optimization) > > Without looking at the code, the downside is that this makes the interface > more complicated. It's very likely that Barry wants the basic interface to > be that users just call KSPSolve repeatedly and take advantage of a recycled > subspace.
In fact that type of thing already exists using the Fischer method. You just turn it on initially with an option and it goes. Since I have not seen the proposed new interface I cannot comment on it. But Jed is totally on the mark, and is ready to take my place as PETSc referee and stylist :-) Barry > Having an interface to manipulate it, or even pull it out as a separate > entity may remain, but if I know Barry, he'll likely tweak things so that the > basic interface does not involve the user doing anything special with a > subspace. With that in mind, you might want to wait until it goes into > petsc-dev before committing the libmesh interface. > ------------------------------------------------------------------------------ > Forrester recently released a report on the Return on Investment (ROI) of > Google Apps. They found a 300% ROI, 38%-56% cost savings, and break-even > within 7 months. Over 3 million businesses have gone Google with Google Apps: > an online email calendar, and document program that's accessible from your > browser. Read the Forrester report: > http://p.sf.net/sfu/googleapps-sfnew_______________________________________________ > Libmesh-devel mailing list > Libmesh-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/libmesh-devel ------------------------------------------------------------------------------ Forrester recently released a report on the Return on Investment (ROI) of Google Apps. They found a 300% ROI, 38%-56% cost savings, and break-even within 7 months. Over 3 million businesses have gone Google with Google Apps: an online email calendar, and document program that's accessible from your browser. Read the Forrester report: http://p.sf.net/sfu/googleapps-sfnew _______________________________________________ Libmesh-devel mailing list Libmesh-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libmesh-devel
