Set values of symmetric matrices.

billy at billy at
Thu Jun 22 11:58:43 CDT 2006

It exits with no error message. Usually I see several PETSC error messages
before it exits. I tested with MPIAIJ. It works with KSPGMRES or KSPBCGS but
with KSPCG it exits immediately. Maybe I am missing something.


Quoting Hong Zhang <hzhang at>:

> Billy,
> We support cg with MPIAIJ and MPISBAIJ format.
> > I use MatCreateMPIAIJ to create parallel matrices. I would like to use
> KSPCG to
> > solve a symmetric matrices. I tried to implement it but the program exits
> with
> > no error.
>   ^^^^^^^
> Do you mean with error? If so, what error message?
> >Do I need only to set values on the diagonal and upper diagonal only
> > or continue to set all non-zero entries of the matrix?
> >
> If you use MPISBAIJ matrix format, then you only need to set the diagonal
> and upper diagonals. Setting all non-zero entries of the matrix
> also works - petsc ignores the lower triangular part.
> Hong
> >

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