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