changes to PCASM pushed

Lisandro Dalcin dalcinl at gmail.com
Wed Nov 26 18:43:22 CST 2008


On Wed, Nov 26, 2008 at 1:21 AM, Barry Smith <bsmith at mcs.anl.gov> wrote:
>
>   Looks fine to me; feel free to make the default.

Done.

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

Many thanks!

>
> 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)
>> Instituto de Desarrollo Tecnológico para la Industria Química (INTEC)
>> Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)
>> PTLC - Güemes 3450, (3000) Santa Fe, Argentina
>> Tel/Fax: +54-(0)342-451.1594
>>
>
>



-- 
Lisandro Dalcín
---------------
Centro Internacional de Métodos Computacionales en Ingeniería (CIMEC)
Instituto de Desarrollo Tecnológico para la Industria Química (INTEC)
Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)
PTLC - Güemes 3450, (3000) Santa Fe, Argentina
Tel/Fax: +54-(0)342-451.1594




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