"Smith, Barry F. via petsc-users" <petsc-users@mcs.anl.gov> writes:
> This is an interesting idea, but unfortunately not directly compatible > with libMesh filling up the finite element part of the matrix. Plus it > appears MatGetLocalSubMatrix() is only implemented for IS and Nest matrices > :-( Maybe I'm missing something, but MatGetLocalSubMatrix *is* implemented for arbitrary Mats; it returns a view that allows you to set entries using local submatrix indexing. That was a key feature of the MatNest work from so many years ago and a paper on which you're coauthor. ;-)
