On Wed, Aug 13, 2008 at 06:31:22PM +0200, [EMAIL PROTECTED] wrote: > > > Kent-Andre Mardal wrote: > >> BTW: the Assembler code that computes A, b and enforces BC > >> simultaneously in a symmetric way, > > > > Very nice. We can now implement some symmetric linear solvers. > > > > Do you keep the 'Dirichlet' dofs and zero the row and column, or do you > > eliminate them from the global system? > > The Dirichlet dofs are kept. I thought that was simplest to do.. > > > > is now faster than the standard > >> non-symmetric way of doing it: > >> > >> timings: > >> new : 1.55 > >> standard: 1.94 > >> > > > > Which backend is this using? It could be saying more about the > > efficiency of the function ident(..), which I suspect is slow for > > uBlasMatrix, than the assembly process. > > > > Good point. There is speed up for all backends that I have tried. > Here are the numbers: > > ~/local/src/dolfin/demo/pde/sym-dirichlet-bc >python speed-up-test.py | > grep using > time for standard assembly 1.89726901054 using uBLAS > time for new assembly 1.49513792992 using uBLAS > time for standard assembly 1.97571492195 using PETSc > time for new assembly 1.55099701881 using PETSc > time for standard assembly 2.26576018333 using Epetra > time for new assembly 1.86703896523 using Epetra > > > Kent
Very nice. Is assemble_system fully working now? Can it be safely used for all forms (in particular DG forms)? If so, we can start using it in LinearPDE::solve(). -- Anders
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