On Sat, Feb 11, 2012 at 00:00, recrusader <recrusader at gmail.com> wrote:
> in > http://www.mcs.anl.gov/petsc/petsc-dev/src/ksp/ksp/examples/tutorials/ex43.c.html > > Why are two matrices set to MATAIJ? if I set MATAIJCUSP, is them changed? > > 1468: > DMCreateMatrix<http://www.mcs.anl.gov/petsc/petsc-dev/docs/manualpages/DM/DMCreateMatrix.html#DMCreateMatrix> > (da_Stokes,MATAIJ<http://www.mcs.anl.gov/petsc/petsc-dev/docs/manualpages/Mat/MATAIJ.html#MATAIJ> > ,&A); > > 1469: DMCreateMatrix > <http://www.mcs.anl.gov/petsc/petsc-dev/docs/manualpages/DM/DMCreateMatrix.html#DMCreateMatrix>(da_Stokes,MATAIJ > > <http://www.mcs.anl.gov/petsc/petsc-dev/docs/manualpages/Mat/MATAIJ.html#MATAIJ>,&B); > > You have to follow the code down to where those matrices are used. 1478: AssembleA_Stokes(A,da_Stokes,da_prop,properties); 1479: AssembleA_PCStokes(B,da_Stokes,da_prop,properties); This uses a "block preconditioner", the B matrix is intentionally different from the A matrix in order to handle the saddle point. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20120211/26558454/attachment-0001.htm>
