Lisandro, The way I see it the problem with the current code is that any Mat that one creates "knows" how to do factorizations. For example it has MatCholeskyFactorSymbolic(). Thus if one wants to use a Mumps factorization one needs a different matrix class (MATAIJMUMPS for example), this is difficult for users to understand and also silly since WAY back in the code before I start filling up my matrix, the LU I want to use comes into play. The original "fix" I proposed was MatSetSolverType() that would allow one to set the solver type to the matrix LATER. This would have essentially been like calling a MatConvert() on the matrix to a specialized form like MATAIJMUMPS. A major drawback to this approach is that it keeps all the horrible, horrible, MatConvert() code to the specialized type that is ugly, bug ridden and impossible to maintain extend and understand. Then I realized a clean solution that eliminates ALL the ugly convert code. It comes with the realization that the factor routines belong as methods on the FACTORED matrix (since it is the factored matrix algorithm and data structures that are affected by the MUMPS, SuperLU etc), not the original matrix. Thus ALL the convert crap can be dumped :-). My current test model is MatGetFactor(Mat A,MatSolverType,MatFactorType,Mat *fact); followed by MatLUFactorSymbolic(fact,A,.....) Once I have it all working I am, of course, open to name suggestions and tweaks. Once you see it you'll like it :-) Barry On Jun 23, 2008, at 2:29 PM, Lisandro Dalcin wrote:

On 6/23/08, Barry Smith <[email protected]> wrote:

...

It will be gone.

Ups! Was this decided in some private discussion? I remember the post were you proposed this; I also remember there were some objections, but you started it anyway, so I guessed that this was already accepted.

IMHO, the whole idea was +1 for me (though I did not commented on this). Did you change your mind? Was this rejected for the other developers in the PETSc team? Was a better mechanism devised?

-- Lisandro Dalc�n --------------- Centro Internacional de M�todos Computacionales en Ingenier�a (CIMEC) Instituto de Desarrollo Tecnol�gico para la Industria Qu�mica (INTEC) Consejo Nacional de Investigaciones Cient�ficas y T�cnicas (CONICET) PTLC - G�emes 3450, (3000) Santa Fe, Argentina Tel/Fax: +54-(0)342-451.1594