Ifpack2_Diagonal_decl.hpp

// @HEADER
// *****************************************************************************
//       Ifpack2: Templated Object-Oriented Algebraic Preconditioner Package
//
// Copyright 2009 NTESS and the Ifpack2 contributors.
// SPDX-License-Identifier: BSD-3-Clause
// *****************************************************************************
// @HEADER

#ifndef IFPACK2_DIAGONAL_DECL_HPP
#define IFPACK2_DIAGONAL_DECL_HPP

#include "Ifpack2_Preconditioner.hpp"
#include "Ifpack2_Details_CanChangeMatrix.hpp"
#include "Tpetra_CrsMatrix_decl.hpp"
#include <type_traits>

namespace Ifpack2 {

template<class MatrixType>
class Diagonal :
    virtual public Ifpack2::Preconditioner<typename MatrixType::scalar_type,
                                           typename MatrixType::local_ordinal_type,
                                           typename MatrixType::global_ordinal_type,
                                           typename MatrixType::node_type>,
    virtual public Ifpack2::Details::CanChangeMatrix<Tpetra::RowMatrix<typename MatrixType::scalar_type,
                                                                       typename MatrixType::local_ordinal_type,
                                                                       typename MatrixType::global_ordinal_type,
                                                                       typename MatrixType::node_type> >
{
public:
  typedef typename MatrixType::scalar_type scalar_type;
  typedef typename MatrixType::local_ordinal_type local_ordinal_type;
  typedef typename MatrixType::global_ordinal_type global_ordinal_type;
  typedef typename MatrixType::node_type node_type;
  typedef typename Teuchos::ScalarTraits<scalar_type>::magnitudeType magnitude_type;

  typedef Tpetra::RowMatrix<scalar_type,
                            local_ordinal_type,
                            global_ordinal_type,
                            node_type> row_matrix_type;

  static_assert(std::is_same<MatrixType, row_matrix_type>::value, "Ifpack2::Diagonal: The template parameter MatrixType must be a Tpetra::RowMatrix specialization.  Please don't use Tpetra::CrsMatrix (a subclass of Tpetra::RowMatrix) here anymore.  The constructor can take either a RowMatrix or a CrsMatrix just fine.");

  typedef Tpetra::CrsMatrix<scalar_type,
                            local_ordinal_type,
                            global_ordinal_type,
                            node_type> crs_matrix_type;
  typedef Tpetra::Vector<scalar_type,
                         local_ordinal_type,
                         global_ordinal_type,
                         node_type> vector_type;
  typedef Tpetra::Map<local_ordinal_type,
                      global_ordinal_type,
                      node_type> map_type;

  Diagonal (const Teuchos::RCP<const row_matrix_type>& A);

  Diagonal (const Teuchos::RCP<const crs_matrix_type>& A_in);

  Diagonal (const Teuchos::RCP<const vector_type>& diag);

  virtual ~Diagonal ();


  void setParameters (const Teuchos::ParameterList& params);

  void initialize ();

  bool isInitialized () const {
    return isInitialized_;
  }

  void compute ();

  bool isComputed () const {
    return isComputed_;
  }



  virtual void
  setMatrix (const Teuchos::RCP<const row_matrix_type>& A);



  void
  apply (const Tpetra::MultiVector<scalar_type,local_ordinal_type,global_ordinal_type,node_type>& X,
         Tpetra::MultiVector<scalar_type,local_ordinal_type,global_ordinal_type,node_type>& Y,
         Teuchos::ETransp mode = Teuchos::NO_TRANS,
         scalar_type alpha = Teuchos::ScalarTraits<scalar_type>::one(),
         scalar_type beta = Teuchos::ScalarTraits<scalar_type>::zero()) const;

  Teuchos::RCP<const map_type> getDomainMap () const;

  Teuchos::RCP<const map_type> getRangeMap () const;



  //Teuchos::RCP<const Teuchos::Comm<int> > getComm () const;

  Teuchos::RCP<const row_matrix_type> getMatrix () const {
    return matrix_;
  }

  double getComputeFlops() const;

  double getApplyFlops() const;

  int getNumInitialize() const;

  int getNumCompute() const;

  int getNumApply() const;

  double getInitializeTime() const;

  double getComputeTime() const;

  double getApplyTime() const;



  std::string description() const;

  void
  describe (Teuchos::FancyOStream& out,
            const Teuchos::EVerbosityLevel verbLevel =
            Teuchos::Describable::verbLevel_default) const;

private:
  void reset ();

  Teuchos::RCP<const row_matrix_type> matrix_;

  Teuchos::RCP<const vector_type> userInverseDiag_;

  Teuchos::RCP<const vector_type> inverseDiag_;

  typedef Kokkos::View<size_t*, typename node_type::device_type> offsets_type;
  offsets_type offsets_;

  double initializeTime_;
  double computeTime_;
  mutable double applyTime_;

  int numInitialize_;
  int numCompute_;
  mutable int numApply_;

  bool isInitialized_;
  bool isComputed_;
};

template<class MatrixType, class VectorType>
Teuchos::RCP<Ifpack2::Diagonal<Tpetra::RowMatrix<typename MatrixType::scalar_type,
                                                 typename MatrixType::local_ordinal_type,
                                                 typename MatrixType::global_ordinal_type,
                                                 typename MatrixType::node_type> > >
createDiagonalPreconditioner (const Teuchos::RCP<const VectorType>& invdiag)
{
  typedef Tpetra::RowMatrix<typename MatrixType::scalar_type,
    typename MatrixType::local_ordinal_type,
    typename MatrixType::global_ordinal_type,
    typename MatrixType::node_type> row_matrix_type;

  return Teuchos::rcp (new Ifpack2::Diagonal<row_matrix_type> (invdiag));
}

}//namespace Ifpack2

#endif