sparse_ilu.h

// ---------------------------------------------------------------------
//
// Copyright (C) 1999 - 2018 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.md at
// the top level directory of deal.II.
//
// ---------------------------------------------------------------------


#ifndef dealii_sparse_ilu_h
#define dealii_sparse_ilu_h


#include <deal.II/base/config.h>

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

DEAL_II_NAMESPACE_OPEN

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

  SparseILU() = default;

  using AdditionalData = typename SparseLUDecomposition<number>::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 override;

  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