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#ifndef TPETRA_ROWMATRIXTRANSPOSER_DECL_HPP
#define TPETRA_ROWMATRIXTRANSPOSER_DECL_HPP

/// \file Tpetra_RowMatrixTransposer_decl.hpp
///
/// Declaration of Tpetra::RowMatrixTransposer.

#include <Tpetra_CrsMatrix_decl.hpp>

namespace Tpetra {

/// \class RowMatrixTransposer
/// \brief Construct and (optionally) redistribute the explicitly
///   stored transpose of a CrsMatrix.
///
/// This class is based on the EpetraExt version.  It first transposes
/// the matrix to an intermediate version with overlapping row map.
/// That matrix is then converted to a final version whose row map is
/// "unique", i.e., a row is wholly owned by one process.
///
/// This class takes the same template parameters as CrsMatrix.
template<class Scalar = Details::DefaultTypes::scalar_type,
         class LocalOrdinal = Details::DefaultTypes::local_ordinal_type,
         class GlobalOrdinal = Details::DefaultTypes::global_ordinal_type,
         class Node = Details::DefaultTypes::node_type>
class RowMatrixTransposer {
public:
  //! @name Typedefs
  //@{
  typedef Scalar scalar_type;
  typedef LocalOrdinal local_ordinal_type;
  typedef GlobalOrdinal global_ordinal_type;
  typedef Node node_type;

  typedef Map<LocalOrdinal, GlobalOrdinal, Node> map_type;
  typedef CrsMatrix<Scalar, LocalOrdinal, GlobalOrdinal, Node> crs_matrix_type;

  //@}
  //! @name Constructors
  //@{

  //! Constructor that takes the matrix to transpose.
  RowMatrixTransposer (const Teuchos::RCP<const crs_matrix_type>& origMatrix,const std::string & label = std::string());

  //@}
  //! @name Methods for computing the explicit transpose.
  //@{

  //! Compute and return the transpose of the matrix given to the constructor.
  Teuchos::RCP<crs_matrix_type> createTranspose();

  /// \brief Compute and return the transpose of the matrix given to the constructor.
  ///
  /// In this call, we (potentially) leave the matrix with an
  /// overlapping row Map.  This is a perfectly valid matrix, but
  /// won't work correctly with some routines in Ifpack or Muelu.
  ///
  /// \warning This routine leaves overlapping rows.  Unless you're
  /// sure that's OK, call createTranspose() instead.
  Teuchos::RCP<crs_matrix_type> createTransposeLocal ();

private:
  //! The original matrix to be transposed.
  Teuchos::RCP<const crs_matrix_type> origMatrix_;

  //! Label for timers
  std::string label_;
};


}

#endif /* TPETRA_ROWMATRIXTRANSPOSER_DECL_HPP */
