On Thu, Dec 13, 2012 at 9:30 AM, Peter Brune <prbrune at gmail.com> wrote: > > > > On Thu, Dec 13, 2012 at 11:29 AM, Barry Smith <bsmith at mcs.anl.gov> wrote: >> >> >> On Dec 13, 2012, at 11:27 AM, Peter Brune <prbrune at gmail.com> wrote: >> >> > An abandoned attempt at this lies dormant in src/snes/impls/multiblock. >> > We could try to revive it. >> >> Or at least give it a reasonable name :-( like SNESFIELDSPLIT >> > > +1
I liked multiblock, but its not a big deal. The tough part here is the same as always. We need a nice way to calculate the residual on smaller pieces. Matt >> >> > >> > - Peter >> > >> > >> > On Thu, Dec 13, 2012 at 11:25 AM, Jed Brown <jedbrown at mcs.anl.gov> >> > wrote: >> > Yes, but even more than linear fieldsplit, there are _many_ variations, >> > involving nonlinear change of basis and various types of elimination. I >> > worry that it may be even more complicated and harder to use. >> > >> > >> > On Thu, Dec 13, 2012 at 9:15 AM, Barry Smith <bsmith at mcs.anl.gov> wrote: >> > >> > We could possibly provide the equivalent of PCFieldSplit for nonlinear >> > problems? These could be accelerated via the various non-linear >> > accelerates >> > or even via matrix-free Newton? >> > >> > >> > Barry >> > >> > >> > Begin forwarded message: >> > >> >> From: Jed Brown <jedbrown at mcs.anl.gov> >> >> Subject: Re: Is there any example that allows time-integration provided >> >> by users >> >> Date: December 13, 2012 11:06:29 AM CST >> >> To: Lulu Liu <lulu.liu at kaust.edu.sa>, Barry Smith <bsmith at >> >> mcs.anl.gov> >> >> >> >> It sounds like you want to do classical operator splitting (which is >> >> notoriously inaccurate). The literature on these methods is rife with >> >> special-purpose band-aids that I'd rather not try to support all of in >> >> PETSc. >> >> >> >> My preference would be to write your method as an ARKIMEX, with >> >> "trivial" implicit part on the "part" of the equation that you wanted to >> >> treat explicitly, or if you wanted to solve both implicitly (but >> >> decoupled) >> >> then do the appropriate incomplete solve. Can you be more specific about >> >> what problem you want to solve? >> >> >> >> >> >> On Wed, Dec 12, 2012 at 7:42 AM, Lulu Liu <lulu.liu at kaust.edu.sa> >> >> wrote: >> >> There is two equations in my system, and I want solve the first one, >> >> and then solve the second equation. Is there any example that allows me to >> >> solve equations one by one? >> >> >> >> >> >> I want to solve nonlinear system on every time level, but it is >> >> feasible if I could provide the time discretization schemes by myself. Is >> >> there any example about this? >> >> >> >> Thank you! >> >> >> >> -- >> >> Best wishes, >> >> Lulu Liu >> >> Applied Mathematics and Computational Science >> >> King Abdullah University of Science and Technology >> >> Tel??966?0544701599 >> >> >> >> >> >> This message and its contents, including attachments are intended >> >> solely for the original recipient. If you are not the intended recipient >> >> or >> >> have received this message in error, please notify me immediately and >> >> delete >> >> this message from your computer system. Any unauthorized use or >> >> distribution >> >> is prohibited. Please consider the environment before printing this email. >> >> >> > >> > >> > >> > -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener
