[petsc-users] Question about matrix permutation

[Jed Brown]

On Fri, 29 Jan 2010 09:43:05 -0600 (CST), abhyshr at mcs.anl.gov wrote:
> Instead of calling MatGetSubMatrix to get each submatrix you can use MatGetSubMatrices to extract several submatrices at once. See http://www.mcs.anl.gov/petsc/petsc-as/snapshots/petsc-current/docs/manualpages/Mat/MatGetSubMatrices.html#MatGetSubMatrices.

I don't think Michel was asking to extract multiple matrices.  In
serial, MatGetSubMatrices is implemented by calling MatGetSubMatrix so
there is no weaker assumption on index set sortedness.

Jed