On 4 October 2011 18:05, Kent-Andre Mardal <[email protected]> wrote: > > > On 4 October 2011 18:13, Anders Logg <[email protected]> wrote: >> >> On Tue, Oct 04, 2011 at 04:17:01PM +0100, Garth N. Wells wrote: >> > On 4 October 2011 12:24, Anders Logg <[email protected]> wrote: >> > > SystemAssembler does not support subdomains. It is even silently >> > > ignoring all other integrals than number 0. >> > > >> > > This is one of the remaining bugs for 1.0-beta2. I can try to fix it >> > > but would like some input on what shape the SystemAssembler is >> > > currently in. I haven't touched it that much before since it looks >> > > like a bit of code duplication to me. In particular, is it necessary >> > > to keep both functions cell_wise_assembly and facet_wise_assembly? >> > > >> > >> > It would require some performance testing to decide. I expect that, >> > for performance reasons, both are required. >> >> I'm getting very strange results. Here are results for assembling >> Poisson matrix + vector on a 32 x 32 x 32 unit cube: >> >> Regular assembler: 0.658 s >> System assembler: 9.08 s (cell-wise) >> System assembler: 202 s (facet-wise) >> >> Is this expected? >> >> What are the arguments against ditching SystemAssembler (for less code >> duplication) and adding functionality for symmetric application of BCs >> on the linear algebra level? >> > > > > Earlier system_assemble of A and b was faster than assemble of A and b.
It was faster because it was less general. After being generalised, the performance of SystemAssembler was to all intents and purposes the same as Assembler. > Something strange must have happened. > SystemAssemble enforce symmetric BC elementwise which > is much faster than doing it on linear algebra level. I'm not sure that that is true. In my experience the difference is marginal. Garth > Kent > >> >> -- >> Anders >> >> _______________________________________________ >> Mailing list: https://launchpad.net/~dolfin >> Post to : [email protected] >> Unsubscribe : https://launchpad.net/~dolfin >> More help : https://help.launchpad.net/ListHelp > > _______________________________________________ Mailing list: https://launchpad.net/~dolfin Post to : [email protected] Unsubscribe : https://launchpad.net/~dolfin More help : https://help.launchpad.net/ListHelp
