dolfin team mailing list archive

["Garth N. Wells" <gnw20@xxxxxxxxx>]

On 20 October 2011 11:28, Anders Logg <logg@xxxxxxxxx> wrote:
> The problem was the newly added check that the preconditioner must be
> set to "none" when a direct method is used. This wasn't checked
> before.
>
> The default values have now been changed (in LinearSolver,
> LinearVariationalSoler and NonlinearVariationalSolver) to
>
>  "default"
>  "none"
>

Does this mean that a user who selects an iterative solver will, by
default, not employ any preconditioning?

Garth



> This will result in LU being chosen in LinearSolver.cpp.
>
> All the logic for this is in the constructor of LinearSolver.cpp if
> more tuning is needed.
>
> --
> Anders
>
>
> On Thu, Oct 20, 2011 at 10:22:45AM +0100, Garth N. Wells wrote:
>> What was the problem that has been 'fixed'?
>>
>> Garth
>>
>> ---------- Forwarded message ----------
>> From:  <noreply@xxxxxxxxxxxxx>
>> Date: 20 October 2011 10:11
>> Subject: [Branch ~dolfin-core/dolfin/main] Rev 6347: Fix problem with
>> default values for linear solver and preconditioner,
>> To: Garth Wells <gnw20@xxxxxxxxx>
>>
>>
>> ------------------------------------------------------------
>> revno: 6347
>> committer: Anders Logg <logg@xxxxxxxxx>
>> branch nick: work
>> timestamp: Thu 2011-10-20 11:09:10 +0200
>> message:
>>  Fix problem with default values for linear solver and preconditioner,
>>  now set to "default" and "none".
>> modified:
>>  dolfin/fem/LinearVariationalSolver.h
>>  dolfin/fem/NonlinearVariationalSolver.h
>>  dolfin/la/LinearSolver.h
>>
>>
>
>> === modified file 'dolfin/fem/LinearVariationalSolver.h'
>> --- dolfin/fem/LinearVariationalSolver.h      2011-06-22 10:01:17 +0000
>> +++ dolfin/fem/LinearVariationalSolver.h      2011-10-20 09:09:10 +0000
>> @@ -18,7 +18,7 @@
>>  // Modified by Marie E. Rognes, 2011.
>>  //
>>  // First added:  2011-01-14 (2008-12-26 as VariationalProblem)
>> -// Last changed: 2011-06-22
>> +// Last changed: 2011-10-20
>>
>>  #ifndef __LINEAR_VARIATIONAL_SOLVER_H
>>  #define __LINEAR_VARIATIONAL_SOLVER_H
>> @@ -53,8 +53,8 @@
>>      {
>>        Parameters p("linear_variational_solver");
>>
>> -      p.add("linear_solver", "lu");
>> -      p.add("preconditioner", "default");
>> +      p.add("linear_solver", "default");
>> +      p.add("preconditioner", "none");
>>        p.add("symmetric", false);
>>        p.add("reset_jacobian", true);
>>
>>
>> === modified file 'dolfin/fem/NonlinearVariationalSolver.h'
>> --- dolfin/fem/NonlinearVariationalSolver.h   2011-08-24 22:15:11 +0000
>> +++ dolfin/fem/NonlinearVariationalSolver.h   2011-10-20 09:09:10 +0000
>> @@ -18,7 +18,7 @@
>>  // Modified by Marie E. Rognes, 2011.
>>  //
>>  // First added:  2011-01-14 (2008-12-26 as VariationalProblem.h)
>> -// Last changed: 2011-06-22
>> +// Last changed: 2011-10-20
>>
>>  #ifndef __NONLINEAR_VARIATIONAL_SOLVER_H
>>  #define __NONLINEAR_VARIATIONAL_SOLVER_H
>> @@ -57,8 +57,8 @@
>>      {
>>        Parameters p("nonlinear_variational_solver");
>>
>> -      p.add("linear_solver",  "lu");
>> -      p.add("preconditioner", "default");
>> +      p.add("linear_solver",  "default");
>> +      p.add("preconditioner", "none");
>>        p.add("symmetric", false);
>>        p.add("reset_jacobian", true);
>>
>>
>> === modified file 'dolfin/la/LinearSolver.h'
>> --- dolfin/la/LinearSolver.h  2011-10-07 12:24:30 +0000
>> +++ dolfin/la/LinearSolver.h  2011-10-20 09:09:10 +0000
>> @@ -44,8 +44,8 @@
>>    public:
>>
>>      /// Create linear solver
>> -    LinearSolver(std::string method = "lu",
>> -                 std::string preconditioner = "ilu");
>> +    LinearSolver(std::string method = "default",
>> +                 std::string preconditioner = "none");
>>
>>      /// Destructor
>>      ~LinearSolver();
>>
>
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>