PETScKrylovSolver.h

// Copyright (C) 2004-2015 Johan Jansson and Garth N. Wells
//
// This file is part of DOLFIN.
//
// DOLFIN is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// DOLFIN is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with DOLFIN. If not, see <http://www.gnu.org/licenses/>.
//
// Modified by Anders Logg 2005-2012
// Modified by Johan Hoffman 2005
// Modified by Andy R. Terrel 2005
// Modified by Garth N. Wells 2005-2010

#ifndef __DOLFIN_PETSC_KRYLOV_SOLVER_H
#define __DOLFIN_PETSC_KRYLOV_SOLVER_H

#ifdef HAS_PETSC

#include <map>
#include <memory>
#include <string>
#include <petscksp.h>
#include <dolfin/common/types.h>
#include "GenericLinearSolver.h"
#include "PETScObject.h"

namespace dolfin
{

  class GenericMatrix;
  class GenericVector;
  class PETScBaseMatrix;
  class PETScMatrix;
  class PETScVector;
  class PETScPreconditioner;
  class PETScSNESSolver;
  class VectorSpaceBasis;

  class PETScDMCollection;


  class PETScKrylovSolver : public GenericLinearSolver, public PETScObject
  {
  public:

    enum class norm_type {none, default_norm, preconditioned, unpreconditioned, natural};

    PETScKrylovSolver(MPI_Comm comm,
                      std::string method="default",
                      std::string preconditioner="default");

    PETScKrylovSolver(std::string method="default",
                      std::string preconditioner="default");

    PETScKrylovSolver(MPI_Comm comm,
                      std::string method,
                      std::shared_ptr<PETScPreconditioner> preconditioner);

    PETScKrylovSolver(std::string method,
                      std::shared_ptr<PETScPreconditioner> preconditioner);

    explicit PETScKrylovSolver(KSP ksp);

    virtual ~PETScKrylovSolver();

    void set_operator(std::shared_ptr<const GenericLinearOperator> A);

    void set_operator(const PETScBaseMatrix& A);

    void set_operators(std::shared_ptr<const GenericLinearOperator> A,
                       std::shared_ptr<const GenericLinearOperator> P);

    void set_operators(const PETScBaseMatrix& A, const PETScBaseMatrix& P);

    std::size_t solve(GenericVector& x, const GenericVector& b);

    std::size_t solve(GenericVector& x, const GenericVector& b,
                      bool transpose);

    std::size_t solve(PETScVector& x, const PETScVector& b,
                      bool transpose=false);

    std::size_t solve(const GenericLinearOperator& A, GenericVector& x,
                      const GenericVector& b);

    void set_nonzero_guess(bool nonzero_guess);

    void set_reuse_preconditioner(bool reuse_pc);

    void set_tolerances(double relative, double absolute, double diverged,
                        int max_iter);

    void set_norm_type(norm_type type);

    norm_type get_norm_type() const;

    void monitor(bool monitor_convergence);

    void set_options_prefix(std::string options_prefix);

    std::string get_options_prefix() const;

    void set_from_options() const;

    std::string str(bool verbose) const;

    MPI_Comm mpi_comm() const;

    KSP ksp() const;

    static std::map<std::string, std::string> methods();

    static std::map<std::string, std::string> preconditioners();

    static Parameters default_parameters();

    std::string parameter_type() const
    { return "krylov_solver"; }

    void set_dm(DM dm);

    void set_dm_active(bool val);

    friend class PETScSNESSolver;
    friend class PETScTAOSolver;

  private:

    // Return norm_type enum for norm string
    static PETScKrylovSolver::norm_type get_norm_type(std::string norm);

    // Solve linear system Ax = b and return number of iterations
    std::size_t _solve(const PETScBaseMatrix& A, PETScVector& x,
                       const PETScVector& b);

    // Report the number of iterations
    void write_report(int num_iterations, KSPConvergedReason reason);

    void check_dimensions(const PETScBaseMatrix& A, const GenericVector& x,
                          const GenericVector& b) const;

    // Available solvers
    static const std::map<std::string, const KSPType> _methods;

    // Available solvers descriptions
    static const std::map<std::string, std::string> _methods_descr;

    // PETSc solver pointer
    KSP _ksp;

    // Preconditioner
    std::shared_ptr<PETScPreconditioner> _preconditioner;

    bool preconditioner_set;

  };

}

#endif

#endif