iterator_product.h

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/*
 * Copyright (c) 2011-2015:  G-CSC, Goethe University Frankfurt
 * Author: Arne Nägel
 * 
 * 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__UG__LIB_DISC__OPERATOR__LINEAR_OPERATOR__PRODUCT__
#define __H__UG__LIB_DISC__OPERATOR__LINEAR_OPERATOR__PRODUCT__
 
#include "lib_algebra/operator/interface/linear_iterator.h"
#include "common/util/smart_pointer.h"
#include <vector>
 
#ifdef UG_PARALLEL
#include "lib_algebra/parallelization/parallelization.h"
#endif
 
namespace ug{
 
template <typename X, typename Y>
class CombinedLinearIterator : public ILinearIterator<X,Y>
{
  public:
    CombinedLinearIterator() {};
 
    CombinedLinearIterator(const std::vector<SmartPtr<ILinearIterator<X,Y> > >& vIterator)
      : m_vIterator(vIterator)
    {};
 
    //  Name of Iterator
    virtual const char* name() const = 0;
 
    virtual bool supports_parallel() const
    {
      for(size_t i = 0; i < m_vIterator.size(); ++i)
        if(!m_vIterator[i]->supports_parallel())
          return false;
      return true;
    }
 
    //  Prepare for Operator J(u) and linearization point u (current solution)
    virtual bool init(SmartPtr<ILinearOperator<Y,X> > J, const Y& u) = 0;
 
    // Prepare for Linear Operator L
    virtual bool init(SmartPtr<ILinearOperator<Y,X> > L) = 0;
 
    // Compute correction
    virtual bool apply(Y& c, const X& d) = 0;
 
    // Compute correction and update defect
    virtual bool apply_update_defect(Y& c, X& d) = 0;
 
    void add_iterator(SmartPtr<ILinearIterator<X,Y> > I) {m_vIterator.push_back(I);}
 
    void add_iterator(SmartPtr<ILinearIterator<X,Y> > I,size_t nr) { for (size_t i=0;i<nr;i++) m_vIterator.push_back(I);}
 
    //  Clone
    virtual SmartPtr<ILinearIterator<X,Y> > clone() = 0;
 
  protected:
    std::vector<SmartPtr<ILinearIterator<X,Y> > > m_vIterator;
};
 
 
template <typename X, typename Y>
class LinearIteratorProduct : public CombinedLinearIterator<X,Y>
{
  protected:
    typedef CombinedLinearIterator<X,Y> base_type;
    using base_type::m_vIterator;
 
  public:
    LinearIteratorProduct() {};
 
    LinearIteratorProduct(const std::vector<SmartPtr<ILinearIterator<X,Y> > >& vIterator)
      : CombinedLinearIterator<X,Y>(vIterator)
    {};
 
    //  Name of Iterator
    virtual const char* name() const {return "IteratorProduct";}
 
    //  Prepare for Operator J(u) and linearization point u (current solution)
    virtual bool init(SmartPtr<ILinearOperator<Y,X> > J, const Y& u) {
      bool bRes = true;
      for(size_t i = 0; i < m_vIterator.size(); i++){
        if ((i>0) && (m_vIterator[i]==m_vIterator[i-1])) continue;
        bRes &= m_vIterator[i]->init(J,u);
      }
      return bRes;
    }
 
    // Prepare for Linear Operator L
    virtual bool init(SmartPtr<ILinearOperator<Y,X> > L)
    {
      bool bRes = true;
      for(size_t i = 0; i < m_vIterator.size(); i++) {
        if ((i>0) && (m_vIterator[i]==m_vIterator[i-1])) continue;
        bRes &= m_vIterator[i]->init(L);
      }
      return bRes;
    }
 
    // Compute correction
    virtual bool apply(Y& c, const X& d)
    {
      // create temporary defect and forward request
      SmartPtr<X> spDTmp = d.clone();
      return apply_update_defect(c, *spDTmp);
    }
 
    // Compute correction and update defect
    virtual bool apply_update_defect(Y& c, X& d)
    {
      SmartPtr<Y> spCTmp = c.clone_without_values();
 
      bool bRes = true;
      c.set(0.0);
      for(size_t i = 0; i < m_vIterator.size(); i++)
      {
        bRes &= m_vIterator[i]->apply_update_defect(*spCTmp,d);
        c += (*spCTmp);
      }
      return bRes;
    }
 
    //  Clone
    virtual SmartPtr<ILinearIterator<X,Y> > clone() {
      return make_sp(new LinearIteratorProduct(*this));
    }
};
 
template <typename X, typename Y>
class LinearIteratorSum : public CombinedLinearIterator<X,Y>
{
  protected:
    typedef CombinedLinearIterator<X,Y> base_type;
    using base_type::m_vIterator;
 
  public:
    LinearIteratorSum() {};
 
    LinearIteratorSum(const std::vector<SmartPtr<ILinearIterator<X,Y> > >& vIterator)
      : CombinedLinearIterator<X,Y>(vIterator)
    {};
 
    //  Name of Iterator
    virtual const char* name() const {return "IteratorProduct";}
 
    //  Prepare for Operator J(u) and linearization point u (current solution)
    virtual bool init(SmartPtr<ILinearOperator<Y,X> > J, const Y& u) {
      m_spOp = J;
      bool bRes = true;
      for(size_t i = 0; i < m_vIterator.size(); i++){
        if ((i>0) && (m_vIterator[i]==m_vIterator[i-1])) continue;
        bRes &= m_vIterator[i]->init(J,u);
      }
      return bRes;
    }
 
    // Prepare for Linear Operator L
    virtual bool init(SmartPtr<ILinearOperator<Y,X> > L)
    {
      m_spOp = L;
      bool bRes = true;
      for(size_t i = 0; i < m_vIterator.size(); i++) {
        if ((i>0) && (m_vIterator[i]==m_vIterator[i-1])) continue;
        bRes &= m_vIterator[i]->init(L);
      }
      return bRes;
    }
 
    // Compute correction
    virtual bool apply(Y& c, const X& d)
    {
      // create temporary correction
      SmartPtr<Y> spCTmp = c.clone_without_values();
 
      // this part computes all corrections independently
      c.set(0.0);
 
      bool bRes = true;
      for(size_t i = 0; i < m_vIterator.size(); i++)
      {
        bRes &= m_vIterator[i]->apply(*spCTmp,d);
        c += (*spCTmp);
      }
 
      return bRes;
    }
 
    //  Compute correction and update defect
    virtual bool apply_update_defect(Y& c, X& d)
    {
      bool bRet = apply(c, d);
      m_spOp->apply_sub(d, c);
      return bRet;
    }
 
    //  Clone
    virtual SmartPtr<ILinearIterator<X,Y> > clone() {
      return make_sp(new LinearIteratorSum(*this));
    }
 
  protected:
    SmartPtr<ILinearOperator<Y,X> > m_spOp;
};
 
 
} // end namespace ug
 
#endif