On Wed, Mar 7, 2012 at 1:54 AM, Klaij, Christiaan <C.Klaij at marin.nl> wrote:
> > > >Could you get a stack trace with gdb? Also, I ran on petsc-dev. > > > > > > Breakpoint 1, vecsumsegv::vecsumsegv (this=0x7fffffffd310, m=3, n=4) > > > at vecsumsegv.cc:28 > > > 28 ierr = VecSum(x,&val); > > > (gdb) next > > > > > > This was fixed in petsc-dev. > > > > http://petsc.cs.iit.edu/petsc/petsc-dev/rev/3b9bc425b217 > > Thanks, I'll switch to petsc-dev for this. > > > > > > > Why are you using VecNest? It causes more harm than good in all but some > > very special circumstances. > > I'm using it to experiment with PETSc's block preconditioners. In > short, I have a block matrix for the 2D Stokes eqs with the > variables arranged as (u1,...,uN,v1,...,vN,p1,...pN). The matrix > has the form A = [Q G, D 0]. I'm using VecCreateNest to assemble > the vector x = [u p], just like I use MatCreateNest to assemble > the matrix A from the blocks Q, G and D. The index sets are the > ones you helped me with in a previous thread > ( > https://lists.mcs.anl.gov/mailman/htdig/petsc-users/2012-February/012262.html > ) > This is just an optimization for block PCs, and for vectors I think it makes almost no difference. Matt > dr. ir. Christiaan Klaij > CFD Researcher > Research & Development > E mailto:C.Klaij at marin.nl > T +31 317 49 33 44 > > MARIN > 2, Haagsteeg, P.O. Box 28, 6700 AA Wageningen, The Netherlands > T +31 317 49 39 11, F +31 317 49 32 45, I www.marin.nl > > -- 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 -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20120307/97141f67/attachment.htm>
