KSP/PC choice

[Lisandro Dalcin]

> On Mon, 23 Jul 2007, Lisandro Dalcin wrote:
> I think it's the same that I am using, but I am not sure.  Can you
> give me a helpful reference?

You can start here. This paper computes stab. params. using element
mat and vecs, but you can also found explicit formulas (look for UGN
subindices in formulas)

http://www.mems.rice.edu/TAFSM/PUB_PRE/jALL/j89-CMAME-EBTau.pdf

> I'm currently trying Matt's suggestion (to use MUMPS).  (It seems not
> to easy to install MUMPS.)

I istall MUMPS by letting PETSc to download and install it for me.
Always worked.

> Anyway, I would like to try your solution as well.  What would I have to do?

First of all, you should move to the latest PETSc (2.3.3). Next, you
have to be able to assemble a matrix of type MATIS. This implies you
need to setup a ISLocalToGlobalMapping, by passing to it all local
indices of degrees of freedom you have in the local processor.
Once you have done this, you should be able to solve in parallel an
small problem using PCJACOBI (jacobi, not block-jacobi).

Next, mail me again. Using my preconditioner should then work out of
the box. If you can confirm some gains, I would consider it to be
added to PETSc.

Regards,


-- 
Lisandro Dalcín
---------------
Centro Internacional de Métodos Computacionales en Ingeniería (CIMEC)
Instituto de Desarrollo Tecnológico para la Industria Química (INTEC)
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