On Tue, Feb 25, 2014 at 4:12 PM, Jed Brown <[email protected]> wrote:
> Xiangdong <[email protected]> writes: > > > For the MatSetValuesStencil, should it always work in pair with > > DMCreateMatrix? > > Yes, or MatSetStencil. > > > However, in some example, e.g., src/ksp/ksp/examples/tutorials/ex25.c, > the > > DMCreateMatrix is never called. Is it because KspSetComputeOperators is > > used and DMCreateMatrix is called implicitly somewhere? > > No, it is just testing that certain functionality works even if the DM > is not set. If you have a DM, we recommend setting it. > I am not clear about this. In this example, where is the format declaration (e.g.,mpiaij) of Mat jac? Why is this mat jac always distributed in a compatible way as the DM vectors? Thanks. Xiangdong
