preconditioned_linear_operator_inverse.h

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/*
 * Copyright (c) 2013-2015:  G-CSC, Goethe University Frankfurt
 * Author: Andreas Vogel
 * 
 * This file is part of UG4.
 * 
 * UG4 is free software: you can redistribute it and/or modify it under the
 * terms of the GNU Lesser General Public License version 3 (as published by the
 * Free Software Foundation) with the following additional attribution
 * requirements (according to LGPL/GPL v3 §7):
 * 
 * (1) The following notice must be displayed in the Appropriate Legal Notices
 * of covered and combined works: "Based on UG4 (www.ug4.org/license)".
 * 
 * (2) The following notice must be displayed at a prominent place in the
 * terminal output of covered works: "Based on UG4 (www.ug4.org/license)".
 * 
 * (3) The following bibliography is recommended for citation and must be
 * preserved in all covered files:
 * "Reiter, S., Vogel, A., Heppner, I., Rupp, M., and Wittum, G. A massively
 *   parallel geometric multigrid solver on hierarchically distributed grids.
 *   Computing and visualization in science 16, 4 (2013), 151-164"
 * "Vogel, A., Reiter, S., Rupp, M., Nägel, A., and Wittum, G. UG4 -- a novel
 *   flexible software system for simulating pde based models on high performance
 *   computers. Computing and visualization in science 16, 4 (2013), 165-179"
 * 
 * This program 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.
 */
 
#ifndef __H__LIB_ALGEBRA__OPERATOR__INTERFACE__PRECONDITIONED_LINEAR_OPERATOR_INVERSE__
#define __H__LIB_ALGEBRA__OPERATOR__INTERFACE__PRECONDITIONED_LINEAR_OPERATOR_INVERSE__
 
#include "linear_operator_inverse.h"
#include "linear_iterator.h"
#include "lib_algebra/operator/debug_writer.h"
#include "common/util/smart_pointer.h"
#include "lib_algebra/operator/convergence_check.h"
#include "common/log.h"
#include "linear_solver_profiling.h"
 
#undef DEBUG_FOR_AMG
 
namespace ug{
// Inverse of a Linear Operator using a ILinearIterator as preconditioner
 
 
template <typename X>
class IPreconditionedLinearOperatorInverse
  : public ILinearOperatorInverse<X>,
    public VectorDebugWritingObject<X>
{
  public:
    typedef X domain_function_type;
 
    typedef X codomain_function_type;
 
    typedef ILinearOperatorInverse<X,X> base_type;
 
  protected:
    using base_type::linear_operator;
    using base_type::m_spConvCheck;
 
  public:
    using VectorDebugWritingObject<X>::write_debug;
    using base_type::name;
    using base_type::apply_return_defect;
 
  public:
    IPreconditionedLinearOperatorInverse()
      : m_bRecompute(false), m_spPrecond(NULL)
#ifdef DEBUG_FOR_AMG
, m_amgDebug(0)
#endif
    {}
 
    IPreconditionedLinearOperatorInverse(SmartPtr<ILinearIterator<X,X> > spPrecond)
      : m_bRecompute(false), m_spPrecond(spPrecond)
#ifdef DEBUG_FOR_AMG
, m_amgDebug(0)
#endif
    {}
 
    IPreconditionedLinearOperatorInverse(SmartPtr<ILinearIterator<X,X> > spPrecond,
                                         SmartPtr<IConvergenceCheck<X> > spConvCheck)
      :   base_type(spConvCheck),
        m_bRecompute(false), m_spPrecond(spPrecond)
#ifdef DEBUG_FOR_AMG
, m_amgDebug(0)
#endif
    {}
 
    void set_preconditioner(SmartPtr<ILinearIterator<X, X> > spPrecond)
    {
      m_spPrecond = spPrecond;
    }
 
    SmartPtr<ILinearIterator<X, X> > preconditioner(){return m_spPrecond;}
    ConstSmartPtr<ILinearIterator<X, X> > preconditioner() const {return m_spPrecond;}
 
    virtual bool init(SmartPtr<ILinearOperator<X,X> > J, const X& u)
    {
      if(!base_type::init(J, u)) return false;
 
      LS_PROFILE_BEGIN(LS_InitPrecond);
      if(m_spPrecond.valid())
        if(!m_spPrecond->init(J, u))
          UG_THROW(name() << "::init: Cannot init Preconditioner "
                          "Operator for Operator J.");
      LS_PROFILE_END(LS_InitPrecond);
 
      return true;
    }
 
    virtual bool init(SmartPtr<ILinearOperator<X,X> > L)
    {
      if(!base_type::init(L)) return false;
 
      LS_PROFILE_BEGIN(LS_InitPrecond);
      if(m_spPrecond.valid())
        if(!m_spPrecond->init(L))
          UG_THROW(name() <<"::prepare: Cannot init Preconditioner "
                            "Operator for Operator L.");
      LS_PROFILE_END(LS_InitPrecond);
 
      return true;
    }
 
    virtual bool apply(X& x, const X& b)
    {
    //  copy defect
      SmartPtr<X> spB = b.clone(); X& bTmp = *spB;
//      X bTmp; bTmp.resize(b.size()); bTmp = b;
 
    //  solve on copy of defect
      bool bRes = apply_return_defect(x, bTmp);
 
    //  write updated defect
      write_debug(bTmp, "LS_UpdatedDefectEnd.vec");
 
    //  compute defect again, for debug purpose
      if(m_bRecompute)
      {
      //  recompute defect
        bTmp = b; linear_operator()->apply_sub(bTmp, x);
        number norm = bTmp.norm();
 
      //  print norm of recomputed defect
        UG_LOG("%%%% DEBUG "<<name()<<": (Re)computed defect has norm: "
               <<norm<<"\n");
 
      //  write true end defect
        write_debug(bTmp, "LS_TrueDefectEnd.vec");
      }
 
#ifdef DEBUG_FOR_AMG
      if (m_amgDebug>0)
      {
      // convergence post-check
      X myError(x.size());
      myError.set_random(-1.0, 1.0);
 
      bTmp.set(0.0);
 
      this->write_debug(myError, "AMGDebugPre");
      apply_return_defect(myError, bTmp);
      this->write_debug(myError, "AMGDebugPost");
      }
#endif
 
 
    //  return
      return bRes;
    }
 
    std::string config_string_preconditioner_convergence_check() const
    {
      std::stringstream ss;
      ss << " Convergence Check: ";
      if(m_spConvCheck.valid()) ss << ConfigShift(m_spConvCheck->config_string()) << "\n";
      else ss << "  NOT SET!\n";
      ss << " Preconditioner: ";
      if(m_spPrecond.valid()) ss << ConfigShift(m_spPrecond->config_string()) << "\n";
      else ss << "  NOT SET!\n";
      return ss.str();
    }
 
    virtual std::string config_string() const
    {
      std::stringstream ss;
      ss << name() << "\n" << config_string_preconditioner_convergence_check();
      return ss.str();
    }
 
    void set_compute_fresh_defect_when_finished(bool bRecompute)
    {
      m_bRecompute = bRecompute;
    }
 
  protected:
    bool m_bRecompute;
    SmartPtr<ILinearIterator<X,X> > m_spPrecond;
 
#ifdef DEBUG_FOR_AMG
  public:
    void set_debug_amg(int b) {m_amgDebug = b;}
    int m_amgDebug;
#endif
};
 
}
#endif /* __H__LIB_ALGEBRA__OPERATOR__INTERFACE__PRECONDITIONED_LINEAR_OPERATOR_INVERSE__ */