Dear Barry: thank you for your reply. if the distribution of A11 and B is different, it will not work if I do B*A11?
Happy holiday:). Regards, Yujie On Wed, Dec 24, 2008 at 11:15 AM, Barry Smith <bsmith at mcs.anl.gov> wrote: > > If you want the resulting A11, etc to have the same distribution as B then > when you construct A you will > have to construct it with the rows/columns from the 1 block interlaced with > the 2 block. This means > you would form A it would look > a00 a0,n a0,1 a0,n+1 ... > an,0 an,n an,1 an,n+1 .. > a1,0 a1,n ... > .... > > Barry > > > On Dec 23, 2008, at 7:49 PM, Yujie wrote: > > Hi, PETSc Developer >> >> Now, I have two matrices, A and B. A (its dimension is 2N*2N) is MPIDense >> format. B (N*N) is MPIAIJ. >> >> I want to exact four matrices from A, like this >> >> A11 A12 >> >> A= >> >> A21 A22 >> >> each submatrices is multplied by B. My question is if A11, A12, A21, A22 >> have same distribution with B, how to do it with MatGetSubMatrix()? >> >> Thanks a lot. >> >> Regards, >> >> Yujie >> >> > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20081224/b005e085/attachment.htm>
