[WIP] Feature/solverfactory

This MR mainly contains the factory implementation from !5 (closed) with some cleanup:

• Allow creating solvers / preconditioners from ParameterTrees.

• A solver (including preconditioner) can now be configured via an ini file like this:

[solver]
precond = SeqSSOR
solver = CGSolver

[SeqSSOR]
iterations = 1
relaxation = 1.8

[CGSolver]
reduction=1e-9
maxit = 5000
verbose = 3

• The corresponding dune code currently looks like this:

auto solver = SolverPrecondFactory::create<VectorType> (matrix, configuration, "solver");

• Both the actual type of the solver/preconditioner and their parameters can chosen in the ini file.
• It is also possible to create only a solver or only a preconditioner this way. See the factory doxygen for details.

This MR depends on !84 (merged).

Note: change target branch to master, once !84 (merged) is merged!

dune/istl/preconditioners.hh

@@ -12,6 +12,7 @@
 
 #include <dune/common/simd/simd.hh>
 #include <dune/common/unused.hh>
+#include <dune/common/parametertree.hh>
 
 #include "preconditioner.hh"
 #include "solver.hh"
@@ -159,6 +160,27 @@ namespace Dune {
       CheckIfDiagonalPresent<M,l>::check(_A_);
     }
 
+    /*!
+       \brief Constructor.
+
+       \param A The matrix to operate on.
+       \param configuration ParameterTree containing preconditioner parameters.
+
+       ParameterTree Key | Meaning
+       ------------------|------------
+       iterations        | The number of iterations to perform.
+       relaxation        | Common parameter defined [here](@ref ISTL_Factory_Common_Params).
+
+       See \ref ISTL_Factory for the ParameterTree layout and examples.
+     */
+    SeqSSOR (const M& A, const ParameterTree& configuration)
+      : _A_(A)
+    {
+      _n = configuration.get<field_type>("iterations");
+      _w = configuration.get<field_type>("relaxation");
+      CheckIfDiagonalPresent<M,l>::check(_A_);
+    }
+
     /*!
        \brief Prepare the preconditioner.
 
@@ -249,6 +271,17 @@ namespace Dune {
       CheckIfDiagonalPresent<M,l>::check(_A_);
     }
 
+    /*!
+       \copydoc SeqSSOR::SeqSSOR(const M&,const ParameterTree&)
+     */
+    SeqSOR (const M& A, const ParameterTree& configuration)
+      : _A_(A)
+    {
+      _n = configuration.get<field_type>("iterations");
+      _w = configuration.get<field_type>("relaxation");
+      CheckIfDiagonalPresent<M,l>::check(_A_);
+    }
+
     /*!
        \brief Prepare the preconditioner.
 
@@ -354,6 +387,17 @@ namespace Dune {
       CheckIfDiagonalPresent<M,l>::check(_A_);
     }
 
+    /*!
+       \copydoc SeqSSOR::SeqSSOR(const M&,const ParameterTree&)
+     */
+    SeqGS (const M& A, const ParameterTree& configuration)
+      : _A_(A)
+    {
+      _n = configuration.get<field_type>("iterations");
+      _w = configuration.get<field_type>("relaxation");
+      CheckIfDiagonalPresent<M,l>::check(_A_);
+    }
+
     /*!
        \brief Prepare the preconditioner.
 
@@ -440,6 +484,17 @@ namespace Dune {
       CheckIfDiagonalPresent<M,l>::check(_A_);
     }
 
+    /*!
+       \copydoc SeqSSOR::SeqSSOR(const M&,const ParameterTree&)
+     */
+    SeqJac (const M& A, const ParameterTree& configuration)
+      : _A_(A)
+    {
+      _n = configuration.get<field_type>("iterations");
+      _w = configuration.get<field_type>("relaxation");
+      CheckIfDiagonalPresent<M,l>::check(_A_);
+    }
+
     /*!
        \brief Prepare the preconditioner.
 
@@ -679,6 +734,25 @@ namespace Dune {
       bilu0_decomposition(ILU);
     }
 
+    /*!
+       \brief Constructor.
+
+       \param A The matrix to operate on.
+       \param configuration ParameterTree containing preconditioner parameters.
+
+       ParameterTree Key | Meaning
+       ------------------|------------
+       relaxation        | Common parameter defined [here](@ref ISTL_Factory_Common_Params).
+
+       See \ref ISTL_Factory for the ParameterTree layout and examples.
+     */
+    SeqILU0 (const M& A, const ParameterTree& configuration)
+      : ILU(A) // copy A
+    {
+      _w = configuration.get<field_type>("relaxation");
+      bilu0_decomposition(ILU);
+    }
+
     /*!
        \brief Prepare the preconditioner.
 
@@ -769,6 +843,17 @@ namespace Dune {
       bilu_decomposition(A,n,ILU);
     }
 
+    /*!
+       \copydoc SeqSSOR::SeqSSOR(const M&,const ParameterTree&)
+     */
+    SeqILUn (const M& A, const ParameterTree& configuration)
+      : ILU(A.N(),A.M(),M::row_wise)
+    {
+      _n = configuration.get<field_type>("iterations");
+      _w = configuration.get<field_type>("relaxation");
+      bilu_decomposition(A,_n,ILU);
+    }
+
     /*!
        \brief Prepare the preconditioner.
 
@@ -847,6 +932,14 @@ namespace Dune {
       _w(w)
     {}
 
+    /*!
+       \copydoc SeqILU0::SeqILU0(const M&,const ParameterTree&)
+     */
+    Richardson (const ParameterTree& configuration)
+    {
+      _w = configuration.get<field_type>("relaxation");
+    }
+
     /*!
        \brief Prepare the preconditioner.