Dear all, I solved my problem without using any Petsc routine. Thanks anyway!
Eda Smith, Barry F. <[email protected]>, 17 Haz 2019 Pzt, 18:36 tarihinde şunu yazdı: > > If you are using a MPIAIJ matrix that has already been created you can > use MatMPIAIJGetSeqAIJ(). This gives you back on each process the > "diagonal" block and the "off-diagonal" block. > > > > > On Jun 17, 2019, at 7:44 AM, Eda Oktay via petsc-users < > [email protected]> wrote: > > > > Hello everyone, > > > > I am trying to find the off diagonal blocks of a matrix. For example, I > partitioned a 10*10 matrix into 4*4 and 6*6 block sub matrices. I need to > find the other blocks in order to find the number of nonzero elements in > them. > > > > I tried to use MatGetLocalSubMatrix but I couldn't figure out how to > give iscol and isrow. Also, from the manual, ı understood that > MatSetLocalToGlobalMapping should be used before this routine but I > couldn't used it properly because before MatGetLocalSuMatrix, the submatrix > doesn't exist. I tried to give zero to all elements so that I can use > Mapping routine, but I got an error saying that it is invalid. > > > > How can I fix this probelm? > > > > Thank you, > > > > Eda > >
