dolfin team mailing list archive

["Garth N. Wells" <g.n.wells@xxxxxxxxxxxxxxx>]

Quoting Anders Logg <logg@xxxxxxxxx>:

> On Tue, Dec 06, 2005 at 09:51:35PM +0100, Johan Jansson wrote:
> > On Tue, Dec 06, 2005 at 07:38:14PM +0100, Garth N. Wells wrote:
> > > I've had a look at Preconditioner.h and Preconditioner.cpp to try to
> transfer
> > > precondtioner stuff in KrylovSolver to Preconditioner. The code in
> > > Preconditioner.cpp is pretty cryptic though. Is it possible to simply
> it?
> > > 
> > > Garth  
> > > 
> > 
> > Good idea. It should be possibly to simply move everything from
> > KrylovSolver and put it as a function/member of Preconditioner.
> > 
> > The only issue is as Anders describes, that there are two
> > "preconditioner databases", one in PETSc and one consisting of
> > preconditioners defined using the DOLFIN interface. Maybe the enum
> > solution would unify this? Then there would be only one database
> > (DOLFIN's), which could have either PETSc or DOLFIN preconditioners in
> > it.
> 
> It also needs to be possible for a user to implement her own
> preconditioner which is not in the databse.
> 
> But the enum solution is probably fine. At least it's the simplest and
> it doesn't break anything.

I was thinking about defining PETSc preconditioners and a "userdefined"
preconditioner using enum. We could define PETSc preconditioners, a "dolfin"
preconditioner and a "userdefined" preconditioner.

I'm not sure if it's easier to put these into the class Preconditioner or to
break them up in separate classes.

Garth

> 
> /Anders
> 
> > I've cleaned up the Preconditioner implementation a bit, I hope it's
> > easier to follow now. This is the reference I've used now (before I
> > had some other reference/example code which was much more detailed):
> > 
> >
>
http://www-unix.mcs.anl.gov/petsc/petsc-as/snapshots/petsc-current/src/ksp/pc/impls/jacobi/jacobi.c.html#PCJacobi
> > 
> > 
> >   Johan
> > 
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> > 
> 
> -- 
> Anders Logg
> Research Assistant Professor
> Toyota Technological Institute at Chicago
> http://www.tti-c.org/logg/
> 
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