changes to PCASM pushed

[Barry Smith]

    Looks fine to me; feel free to make the default.

    I've also added Fortran interfaces for the two functions.

    Barry

On Nov 25, 2008, at 4:42 PM, Lisandro Dalcin wrote:

> I've pushed my changes to PCASM. I've implemented a 'smart' subdomain
> partitioner based on MatPartitioner, and falling back to a by chunks
> of rows partitioning if no good partitioner is available
> (PCASMCreateSubdomains(), and a convenience routine
> PCASMDestroySubdomains(), as now PCASM takes full ownership of
> subdomain index set and the array memory holding them). I'll really
> appreciate if some of you can review all this, as it was a bit tricky
> for me to get it right for all AIJ matrix types, external partitioner
> package availability, etc. The biggest crap is that I had to build by
> hand a MATMPIADJ, I believe MatConvert() cannot be used in the case of
> block-aij matrices (see comments in source code).
>
> A few things missing:
>
> 1) Make it the default. Easy to do once I get review and feedback and
> you agree to to that.
> 2) More testing. I'll try to do some work this week.
> 3) Fortran interface. I would really appreciate any help here.
>
>
> BTW, the fallback to by-row partitioning (actually the former default)
> could perhaps be done better by reusing some of the sparse reordering
> routines for SPARSEPACK. I'm thinking about finding a
> pseudo-peripheral node, do a level-set traversal, and then do the
> partitioning (of course, handling the case of more than one connected
> component in the graph). Not really smart, but far better that
> partitioning rows in chunks (and more or less equivalent to it for
> structured grids in natural ordering) . However, I believe this should
> really go to a new PETSc-native (only uniprocessor) MatPartitioning
> implementation, righ? Any comments?
>
>
>
>
> -- 
> Lisandro Dalcín
> ---------------
> Centro Internacional de Métodos Computacionales en Ingeniería (CIMEC)
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>