dolfin team mailing list archive

["Garth N. Wells" <gnw20@xxxxxxxxx>]

On 3 September 2012 12:40, Anders Logg <logg@xxxxxxxxx> wrote:
> On Mon, Sep 03, 2012 at 09:21:05AM +0200, Joachim Berdal Haga wrote:
>> > re-assembling the coefficient matrix. SystemAssembler OTOH can easily
>> > be reimplemented in terms of SymmetricAssembler + Assembler.
>> > (SymmetricAssembler only does rank-2, to avoid duplication; hence,
>> > both are required)
>>
>> ... and, just to mention it, it wouldn't be a problem to support
>> rank-0/1 as well in SymmetricAssembler, in which case we can get down
>> to one assembler implementation. Plus OpenMP.
>
> If we can get the same speed as Assembler + all the features of
> SymmetricAssembler, then I think both should be merged into one.
>

We should work towards this.  A symmetric assembler should be the
'flagship' since it permits CG and Cholesky for a wide range of
problems.

I have some ideas on how to do what SymmetricAssembler does but
without assembling a whole second sparse matrix.


> Is there an overhead for putting the OpenMP code into the regular
> assembler? We would trivially loop over one color.
>

Generally yes. I'm actively working on this, so it should be left for now.

Garth

> --
> Anders