sparse_ilu.h

// ---------------------------------------------------------------------
//
// Copyright (C) 1999 - 2017 by the deal.II authors
//
// This file is part of the deal.II library.
//
// The deal.II library is free software; you can use it, 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 2.1 of the License, or (at your option) any later version.
// The full text of the license can be found in the file LICENSE at
// the top level of the deal.II distribution.
//
// ---------------------------------------------------------------------


#ifndef dealii_sparse_ilu_h
#define dealii_sparse_ilu_h


#include <deal.II/base/config.h>
#include <deal.II/lac/sparse_matrix.h>
#include <deal.II/lac/sparse_decomposition.h>
#include <deal.II/lac/exceptions.h>

DEAL_II_NAMESPACE_OPEN

template <typename number>
class SparseILU : public SparseLUDecomposition<number>
{
public:
  typedef typename SparseLUDecomposition<number>::size_type size_type;

  SparseILU () = default;

  typedef
  typename SparseLUDecomposition<number>::AdditionalData
  AdditionalData;

  template <typename somenumber>
  void initialize (const SparseMatrix<somenumber> &matrix,
                   const AdditionalData &parameters = AdditionalData());

  template <typename somenumber>
  void vmult (Vector<somenumber>       &dst,
              const Vector<somenumber> &src) const;


  template <typename somenumber>
  void Tvmult (Vector<somenumber>       &dst,
               const Vector<somenumber> &src) const;


  std::size_t memory_consumption () const;

  DeclException1 (ExcInvalidStrengthening,
                  double,
                  << "The strengthening parameter " << arg1
                  << " is not greater or equal than zero!");
  DeclException1 (ExcZeroPivot,
                  size_type,
                  << "While computing the ILU decomposition, the algorithm "
                  "found a zero pivot on the diagonal of row "
                  << arg1
                  << ". This must stop the ILU algorithm because it means "
                  "that the matrix for which you try to compute a "
                  "decomposition is singular.");
};

//---------------------------------------------------------------------------


DEAL_II_NAMESPACE_CLOSE

#endif // dealii_sparse_ilu_h