[petsc-users] SNESSetFunction

[Matthew Knepley]

On Mon, Aug 17, 2015 at 11:46 AM, Reza Yaghmaie <reza.yaghmaie2 at gmail.com>
wrote:

>
> Hi,
>
> I have problems with passing variables through  *SNESSetFunction* in my
> code. basically I have the following subroutines in the main body of the
> Fortran code. Could you provide some insight on how to transfer variables
> into the residual calculation routine (*FormFunction1*)?
>

Extra arguments to your FormFunction are meant to be passed in a context,
through the context variable.

This is difficult in Fortran, but you can use a PetscObject as a container.
You can attach other
PetscObjects using PetscObjectCompose() in Fortran.

   Matt


> Thanks,
> Reza
>
> ------------------------------------------------------------------------------------------------------------------
> *main code*
>
> *SNES*      snes
> *Vec*          xvec,rvec
> *external*   FormFunction1
> *real*8*
>  variable1(10),variable2(20,20),variable3(30),variable4(40,40)
>
>
>       call *SNESSetFunction*(snes,rvec,FormFunction1,
>      & PETSC_NULL_OBJECT,
>      & variable1,variable2,variable3,variable4,
>      & ierr)
>
>       end
>
>       subroutine *FormFunction1*(snes,XVEC,FVEC,
>      & dummy,
>      & varable1,varable2,varable3,varable4,
>      & ierr)
>
> *SNES*                      snes
> *Vec*                         XVEC,FVEC
> *PetscFortranAddr*    dummy
> *real*8*
>  variable1(10),variable2(20,20),variable3(30),variable4(40,40)
>
>
>       return
>       end
>
> --------------------------------------------------------------------------------------------------------------
>
>
>
>
>
>


-- 
What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which their
experiments lead.
-- Norbert Wiener
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20150817/50d16b9a/attachment.html>