> On Jul 26, 2018, at 10:34 AM, Xiangdong <[email protected]> wrote:
>
> Hello everyone,
>
> I have a question about get the sub matrix Aodd from a MPIBAIJ matrix A. For
> example, if the bs=2 and the matrix size is 10x10. How can I get the 5x5
> submatrix corresponding to the odd rows and odd columns only?
>
> I tried to use the MatCreateSubMatrix, but get the error messages "Index set
> does not match blocks". It seems that MatCreateSubMatrix can only provide the
> whole block, instead of just a specific component of that block.
>
> Can you give me some suggestions on extracting the submatrix corresponding to
> a specific component?
Either create a AIJ matrix originally or use MatConvert to convert from BAIJ
to AIJ and then use MatCreateSubMatrix(). Note that AIJ provides a great deal
more flexibility with the utilities and solvers than BAIJ.
Barry
>
> Thank you.
>
> Best,
> Xiangdong
