Dear Matthew: thank you very much. Regarding my problem about MatAXPY() for MPIDense, I have checked SEQDense has this function. To my knowledge, in each node, MPIDense's format is SEQDense, right? if it is, I should ba able to write a MPIDense-based function using SEQDense? thanks a lot.
Regards, Yujie On Wed, Dec 31, 2008 at 8:56 AM, Matthew Knepley <knepley at gmail.com> wrote: > Yes, you can have 0 length IS arguments. > > Matt > > > On Wed, Dec 31, 2008 at 10:21 AM, Yujie <recrusader at gmail.com> wrote: > >> Hi, PETSc Developers >> >> In parallel mode, I have 3 MPIDense matrices, A1, A2, A3. Now, I need to >> exact submatrices B1, B2, B3 in parallel mode from A1, A2, A3 respectively. >> I know I should use MatGetSubMatrix(). My problem is in >> >> MatGetSubMatrix(Mat mat,IS isrow,IS iscol,PetscInt csize,MatReuse cll,Mat >> *newmat) >> >> , the parameter "isrow" means "rows this processor should obtain". if Bi >> in some nodes (cpus) of the cluster (Ai have rows in them) don't have rows, >> is it work? >> >> After getting Bi, I will create MPIDense-based C and combine them into C >> like >> >> B1 >> C= B2 >> B3 >> MatGetRow(); >> MatSetValues() should work, right? >> >> Could you give me some comments about these operations? thanks a lot. >> Happy new year! >> >> Regards, >> Yujie >> > > > > -- > 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/20081231/3d7e9f28/attachment.htm>
