[petsc-users] can MatGetSubMatrix extract remote rows?

[Barry Smith]

> On May 19, 2015, at 5:33 PM, Fande Kong <fande.kong at colorado.edu> wrote:
> 
> Hi all,
> 
> I am confused with MatGetSubMatrix and MatGetSubMatrices.  In my understanding, I think MatGetSubMatrix extracts local rows and columns to form another parallel matrix with the same communicator, while MatGetSubMatrices extracts both local and remote entities to construct some sequential matrices. Is it right?

  Yes except that MatGetSubMatrix can also use remote rows (and columns) for the part that is on a particular processor. That is it is not restricted to only grabbing local rows/columns in the new parallel matrix.


> 
> Thanks,
> 
> Fande,