SNESSetUp() and matrix-free options

Lisandro Dalcin dalcinl at
Thu May 7 15:26:25 CDT 2009

On Thu, May 7, 2009 at 5:14 PM, Barry Smith <bsmith at> wrote:
>> 3) I would like to add a call to set matrix-free programatically...
>> something like SNESSetUseMFFD(snes,...). Any signature suggetions
>> regarding my previous discussions about the many options?
>   No need to add this. One can already make the appropriate call to generate
> the
> matrix and set it for the SNES Jacobian. So adding this would be duplicating
> functionality that already exists and hence illegal under PETSc policy.

I understand your rationale, though IMHO the sequences of appropriate
calls are not trivial. We could see this as a convenience routine, and
even use it for SNESSetFromOptions()... Anyway, I'll try to implement
it with a _Private suffix just for consumption in SetFromOptions().

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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