dolfin team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

On Tue, Aug 15, 2006 at 01:38:42PM +0200, Garth N. Wells wrote:
> Anders Logg wrote:
> > I'd like to change the behaviour of classes LU and GMRES so that one
> > may do
> > 
> >     Matrix A;
> >     Vector x, b;
> > 
> >     GMRES::solve(A, x, b);
> > 
> > or
> > 
> >     GMRES::solve(A, x, b, Preconditioner::ilu);
> > 
> > and
> > 
> >     LU::solve(A, x, b);
> > 
> > LU and GMRES would thus not be subclasses or typedefs of
> > PETSc/uBlasLU/KrylovSolver but instead simple classes with static
> > functions for simple solution of linear systems. This would then be
> > the fast and easy way to solve a linear system. For more advanced
> > usage, one would create a KrylovSolver or PETScKrylovSolver and then
> > call solver.solve(). But often, one only wants to solve one linear
> > system and not many and then it's convenient to skip the extra step of
> > creating the solver.
> > 
> 
> OK with me.

ok. I can fix this (if it works out with the preconditioners).

> > This connects to the design of preconditioners. I think we decided to
> > put the list of preconditioners in Preconditioner so this should be
> > ok. What's the status of the redesign of preconditioners?
> > 
> 
> I don't that think we settled on the design of the preconiditoners. It 
> would be nice to have just one enum list of preconditioners in 
> Preconditioner.h, but I haven't had time to look at it yet.

ok. Would it be enough to have a class Preconditioner which just lists
all available preconditioners by name (ilu etc) in an enum type? And
then the solvers just return a run-time error if the preconditioner is
not implemented.

/Anders