dolfin team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

On Tue, Apr 19, 2011 at 09:54:43AM -0700, Johan Hake wrote:
> On Tuesday April 19 2011 09:45:58 Chaffra wrote:
> > Question #153459 on DOLFIN changed:
> > https://answers.launchpad.net/dolfin/+question/153459
> >
> > Chaffra gave more information on the question:
> > The newton_solver is no longer accessible from VariationalProblem. I used
> > to be able to set the linear_solver parameters via
> > problem.newton_solver().linear_solver().parameters ... Is there a new way
> > of doing this?
>
> I think Garth is the man to answer this, but I recall he removed that options
> because it became difficult to maintain as the linear solver can be of many
> different types.
>
> The solution, I think, is to create the linear solver before you create the
> NewtonSolver, grab the parameters, create the NewtonSolver, change whatever
> parameters to the LinearSolver you need through the grabed paraemters.

I think I made a change recently to include the Newton solver
parameters in the parameter list for a VariationalProblem.

If you use

  info(problem.parameters, True)

then you should see the parameters for the Newton solver.

The solver type and preconditioner cannot be set by parameters at the
moment. The problem is that the Newton solver gets these parameters in
the constructor. It should use the parameter system instead.

--
Anders