[petsc-dev] ASM request

Dima Karpeyev karpeev at gmail.com
Tue Mar 16 13:29:09 CDT 2010

The way I've written MatFwk so far, it operates on nonoverlapping dof blocks,
but the idea is that we want to first scatter a Vec into an "unrolled" version,
duplicating the overlap dofs.

On Tue, Mar 16, 2010 at 1:26 PM, Jed Brown <jed at 59a2.org> wrote:
> On Tue, 16 Mar 2010 12:51:53 -0500, Barry Smith <bsmith at mcs.anl.gov> wrote:
>> If you use ILU(0) and the inplace option then it only needs one copy
>> of the blocks instead of the two.
> With block Jacobi, it would be possible to avoid copying out the
> sub-blocks by assembling into a matrix with the blocks already defined
> (I think that Dmitry's MatFwk will allow this).  Similarly for
> Neumann-Neumann with many blocks per process.
> It would also be possible to assemble matrices with overlapping
> subdomains, and define MatMult suitably (dropping redundant dofs).  I
> don't know whether Dmitry has plans to support this.
> Jed

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