scalar_matrix_adapter.hh

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/*
 * Copyright (c) 2013-2015:  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 SCALAR_MATRIX_ADAPTER_HH_
#define SCALAR_MATRIX_ADAPTER_HH_
 
#include <cstdlib>
 
#include "lib_algebra/lib_algebra.h"
#include "lib_algebra/lib_algebra_impl.h"
#include "lib_algebra/cpu_algebra_types.h"
 
#include "lib_algebra/common/matrixio/matrix_io.h"
#include "lib_algebra/common/matrixio/matrix_io_mtx.h"
 
#include "common/assert.h"
using namespace ug;
 
// provides an interface for matrix of algebra type B for matrices originally of algebra type A
// allows to access a CPUBlockAlgebra (AT) as a scalar CPUAlgebra (ST)
 
 
template<class MT>
inline void TruncateOffDiag(MT &A, size_t ncmp)
{ UG_ASSERT(0, "Implement!"); }
 
template<>
inline void TruncateOffDiag(CPUAlgebra::matrix_type &A, size_t ncmp)
{
  typedef CPUAlgebra::matrix_type matrix_type;
 
  // for each row
  for (size_t i=0; i<A.num_rows(); ++i)
  {
    // for each column
    for (matrix_type::row_iterator matij = A.begin_row(i);
        matij != A.end_row(i); ++matij)
    {
      size_t j = matij.index();
      if ((i%ncmp) != (j%ncmp))
      {
      //  std::cerr << "Eliminating " << i << ", " << j<< std::endl;
        matij.value() = 0.0;
      }
    }
  }
 
}
 
template<class AT, class ST=CPUAlgebra>
class ScalarMatrixAdapter{
 
public:
  typedef typename AT::matrix_type encapsulated_matrix_type;
  typedef typename ST::matrix_type::value_type value_type;
  static const int blockSize = AT::blockSize;
 
  //typedef typename ST::matrix_type::const_row_iterator const_row_iterator;
 
  ScalarMatrixAdapter(encapsulated_matrix_type& mat) : m_src(mat), m_const(mat) {};
 
  void resize_and_clear(size_t newRows, size_t newCols)
  { m_src.resize_and_clear(newRows/blockSize, newCols/blockSize);}
 
  bool resize_and_keep_values(size_t newRows, size_t newCols)
  {return m_src.resize_and_keep_values(newRows/blockSize, newCols/blockSize);}
 
 
  value_type &operator() (size_t r, size_t c)
  {
    UG_ASSERT(r < num_rows(), "row index is too large");
    UG_ASSERT(c < num_cols(), "col index is too large");
    return BlockRef(m_src(r/blockSize, c/blockSize), r%blockSize, c%blockSize);
  };
 
  const value_type &operator () (size_t r, size_t c)  const
  {
    UG_ASSERT(r < num_rows(), "row index is too large");
    UG_ASSERT(c < num_cols(), "col index is too large");
    return BlockRef(m_src(r/blockSize, c/blockSize), r%blockSize, c%blockSize);
  }
 
  size_t num_rows() const
  { return m_src.num_rows()*blockSize; }
 
  size_t num_cols() const
  { return m_src.num_cols()*blockSize; }
 
  size_t total_num_connections() const
  { return m_src.total_num_connections()*blockSize*blockSize; }
 
  void print(const char *text) const {m_src.print(text);}
 
  void printrow(size_t row) const {m_src.printrow(row/blockSize);}
 
  friend std::ostream& operator<<(std::ostream& os, ScalarMatrixAdapter<AT,ST> const &a)
  { a.outputToStream(os); return os; }
 
  class row_iterator
  {
    typename encapsulated_matrix_type::row_iterator iter;
  public:
    inline void check() const {iter.check(); }
    row_iterator(typename encapsulated_matrix_type::row_iterator _iter)
    : iter(_iter) {}
    ~row_iterator() {}
    row_iterator *operator ->() { return iter.operator->(); }
    bool operator != (const row_iterator &o) const { return *iter != o->iter;  }
    void operator ++ () { ++iter; }
    void operator += (int nr) { iter+=nr; }
    bool operator == (const row_iterator &other) const { return other->iter == *iter;}
    size_t index() const { return iter.index(); }
    value_type &value() { return BlockRef(iter.value(), blockSize, blockSize); }
  };
 
  class const_row_iterator
  {
    typename encapsulated_matrix_type::const_row_iterator iter;
      public:
      inline void check() const {iter.check(); }
      const_row_iterator(typename encapsulated_matrix_type::const_row_iterator _iter)
      : iter(_iter) {}
      ~const_row_iterator() {}
      const_row_iterator *operator ->() { return iter.operator->(); }
      bool operator != (const const_row_iterator &o) const { return iter!= o.iter;  }
      void operator ++ () { ++iter; }
      void operator += (int nr) { iter+=nr; }
      bool operator == (const const_row_iterator &other) const { return other.iter == iter;}
      size_t index() const { return iter.index(); }
      const value_type &value() const { return BlockRef(iter.value(), blockSize, blockSize); }
    };
 
 
  row_iterator begin_row(size_t r)
  { return row_iterator(m_src.begin_row(r)); }
  row_iterator end_row(size_t r)
  { return row_iterator(m_src.end_row(r)); }
 
  const_row_iterator begin_row(size_t r) const
  { return const_row_iterator(m_const.begin_row(r)); }
  const_row_iterator   end_row(size_t r) const
  { return const_row_iterator(m_const.end_row(r)); }
 
protected:
  std::ostream& outputToStream(std::ostream& os) const
  { return os << m_src; }
 
  encapsulated_matrix_type &m_src;
  const encapsulated_matrix_type &m_const;
};
 
 
// partielle Spezialisierung fuer CPUAlgebra
template<>
inline ScalarMatrixAdapter<CPUAlgebra, CPUAlgebra>::value_type&
ScalarMatrixAdapter<CPUAlgebra, CPUAlgebra>::operator () (size_t r, size_t c)
{ return m_src(r,c); };
 
#endif /* SPARSEMATRIXPROXY_HH_ */