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#ifndef IFPACK_KRYLOV_H
#define IFPACK_KRYLOV_H

#include "Ifpack_ConfigDefs.h"
#include "Ifpack_Preconditioner.h"
#include "Teuchos_RefCountPtr.hpp"
#include "Ifpack_PointRelaxation.h"
#include "Ifpack_BlockRelaxation.h"
#include "Ifpack_SparseContainer.h"
#include "Ifpack_DenseContainer.h"
#include "Ifpack_Amesos.h"
#ifdef HAVE_IFPACK_AZTECOO
#include "AztecOO.h"
#endif

namespace Teuchos {
  class ParameterList;
}

class Epetra_MultiVector;
class Epetra_Vector;
class Epetra_Map;
class Epetra_Comm;
class Epetra_Time;
class Epetra_Vector;
class Epetra_Operator;
class Epetra_RowMatrix;
#ifdef HAVE_IFPACK_AZTECOO
class AztecOO;
#endif


#ifdef HAVE_IFPACK_EPETRAEXT
class EpetraExt_PointToBlockDiagPermute;
#endif

//! Ifpack_Krylov: class for smoothing with Krylov solvers in Ifpack

class Ifpack_Krylov : public Ifpack_Preconditioner {

  typedef double                SC;
  typedef Epetra_MultiVector    MV;
  typedef Epetra_Operator       OP;
  typedef Epetra_RowMatrix      RM;

public:

  //@{ \name Constructors/Destructors
  Ifpack_Krylov(Epetra_Operator* Matrix);

  //! Ifpack_Krylov constructor with given Epetra_Operator/Epetra_RowMatrix.
  Ifpack_Krylov(Epetra_RowMatrix* Matrix);

  //! Destructor.
  virtual ~Ifpack_Krylov() {};

  //@}

  /*! This flag can be used to apply the preconditioner to the transpose of
   * the input operator. 
   * 
   * \return Integer error code, set to 0 if successful.  
   * Set to -1 if this implementation does not support transpose.
    */
  virtual inline int SetUseTranspose(bool UseTranspose_in)
  {
    UseTranspose_ = UseTranspose_in;
    return(0);
  }

  //@}

  //@{ \name Mathematical functions.

  //! Applies the matrix to an Epetra_MultiVector.
  /*! 
    \param 
    X - (In) A Epetra_MultiVector of dimension NumVectors to multiply with matrix.
    \param 
    Y - (Out) A Epetra_MultiVector of dimension NumVectors containing the result.

    \return Integer error code, set to 0 if successful.
    */
  virtual inline int Apply(const Epetra_MultiVector& X, Epetra_MultiVector& Y) const;

  //! Applies the preconditioner to X, returns the result in Y.
  /*! 
    \param
    X - (In) A Epetra_MultiVector of dimension NumVectors to be preconditioned.
    \param
    Y - (InOut) A Epetra_MultiVector of dimension NumVectors containing result.

    \return Integer error code, set to 0 if successful.

    \warning This routine is NOT AztecOO complaint.
    */
  virtual int ApplyInverse(const Epetra_MultiVector& X, Epetra_MultiVector& Y) const;

  //! Returns the infinity norm of the global matrix (not implemented)
  virtual double NormInf() const
  {
    return(-1.0);
  }
  //@}

  //@{ \name Attribute access functions

  virtual const char * Label() const
  {
    return(Label_.c_str());
  }

  //! Returns the current UseTranspose setting.
  virtual bool UseTranspose() const
  {
    return(UseTranspose_);
  }

  //! Returns true if the \e this object can provide an approximate Inf-norm, false otherwise.
  virtual bool HasNormInf() const
  {
    return(false);
  }

  //! Returns a pointer to the Epetra_Comm communicator associated with this operator.
  virtual const Epetra_Comm & Comm() const;

  //! Returns the Epetra_Map object associated with the domain of this operator.
  virtual const Epetra_Map & OperatorDomainMap() const;

  //! Returns the Epetra_Map object associated with the range of this operator.
  virtual const Epetra_Map & OperatorRangeMap() const;

  virtual int Initialize();
  
  virtual bool IsInitialized() const
  {
    return(IsInitialized_);
  }

  //! Returns \c true if the preconditioner has been successfully computed.
  virtual inline bool IsComputed() const
  {
    return(IsComputed_);
  }

  //! Computes the preconditioners.
  virtual int Compute();

  virtual const Epetra_RowMatrix& Matrix() const 
  {
    return(*Matrix_);
  }

  //! Computes the condition number estimates and returns the value.
  virtual double Condest(const Ifpack_CondestType CT = Ifpack_Cheap,
                         const int MaxIters = 1550,
                         const double Tol = 1e-9,
                         Epetra_RowMatrix* Matrix_in = 0);

  //! Returns the condition number estimate, or -1.0 if not computed.
  virtual double Condest() const
  {
    return(Condest_);
  }

  //! Sets all the parameters for the preconditioner
  virtual int SetParameters(Teuchos::ParameterList& List);

  //! Prints object to an output stream
  virtual ostream& Print(ostream & os) const;

  //@}

  //@{ \name Timing and flop count

  //! Returns the number of calls to Initialize().
  virtual int NumInitialize() const
  {
    return(NumInitialize_);
  }

  //! Returns the number of calls to Compute().
  virtual int NumCompute() const
  {
    return(NumCompute_);
  }

  //! Returns the number of calls to ApplyInverse().
  virtual int NumApplyInverse() const
  {
    return(NumApplyInverse_);
  }

  //! Returns the time spent in Initialize().
  virtual double InitializeTime() const
  {
    return(InitializeTime_);
  }

  //! Returns the time spent in Compute().
  virtual double ComputeTime() const
  {
    return(ComputeTime_);
  }

  //! Returns the time spent in ApplyInverse().
  virtual double ApplyInverseTime() const
  {
    return(ApplyInverseTime_);
  }

  //! Returns the number of flops in the initialization phase.
  virtual double InitializeFlops() const
  {
    return(0.0);
  }

  //! Returns the number of flops in the computation phase.
  virtual double ComputeFlops() const
  {
    return(ComputeFlops_);
  }

  //! Returns the number of flops for the application of the preconditioner.
  virtual double ApplyInverseFlops() const
  {
    return(ApplyInverseFlops_);
  }

private:
  
  // @}
  // @{ \name Private methods
  
  //! Sets the label.
  virtual void SetLabel();

  //! Copy constructor (PRIVATE, should not be used)
  Ifpack_Krylov(const Ifpack_Krylov& rhs)
  {}
  
  //! operator = (PRIVATE, should not be used)
  Ifpack_Krylov& operator=(const Ifpack_Krylov& rhs)
  {
    return(*this);
  }

  // @{ Initializations, timing and flops
  //! If \c true, the preconditioner has been computed successfully.
  bool IsInitialized_;
  //! If \c true, the preconditioner has been computed successfully.
  bool IsComputed_;
  //! Contains the number of successful calls to Initialize().
  int NumInitialize_;
  //! Contains the number of successful call to Compute().
  int NumCompute_;
  //! Contains the number of successful call to ApplyInverse().
  mutable int NumApplyInverse_;
  //! Contains the time for all successful calls to Initialize().
  double InitializeTime_;
  //! Contains the time for all successful calls to Compute().
  double ComputeTime_;
  //! Contains the time for all successful calls to ApplyInverse().
  mutable double ApplyInverseTime_;
  //! Contains the number of flops for Compute().
  double ComputeFlops_;
  //! Contain sthe number of flops for ApplyInverse().
  mutable double ApplyInverseFlops_;
  // @}

  // @{ Settings
  //! Max number of iterations
  int Iterations_;
  //! Residual Tolerance
  double Tolerance_;
  //! Solver - 0 for CG, 1 for GMRES
  int SolverType_;
  //! Preconditioner - 0 for none, 1 for Jacobi, 2 for GS, 3 for SGS
  int PreconditionerType_;
  //! Number of GS or Jacobi sweeps
  int NumSweeps_;
  //! Block Size (for block relaxation)
  int BlockSize_;
  //! Damping parameter for inner preconditioner
  double DampingParameter_;
  //! If true, use the tranpose of \c Matrix_.
  bool UseTranspose_;
  //! Contains the estimated condition number
  double Condest_;
  //! If true, Compute() also computes the condition number estimate.
  bool ComputeCondest_;
  //! Contains the label of this object.
  string Label_;

  // @{ Other data
  //! Number of local rows.
  int NumMyRows_;
  //! Number of local nonzeros.
  int NumMyNonzeros_;
  //! Number of global rows.
  long long NumGlobalRows_;
  //! Number of global nonzeros.
  long long NumGlobalNonzeros_;
  //! Pointers to the matrix as an Epetra_Operator.
  Teuchos::RefCountPtr<Epetra_Operator> Operator_;
  //! Pointers to the matrix as an Epetra_RowMatrix.
  Teuchos::RefCountPtr<Epetra_RowMatrix> Matrix_;

  //! If \c true, the Operator_ is an Epetra_RowMatrix.
  bool IsRowMatrix_;
  //! Time object to track timing.
  Teuchos::RefCountPtr<Epetra_Time> Time_;
  //! If \c true, the starting solution is always the zero vector.
  bool ZeroStartingSolution_;

  // Aztec solver
#ifdef HAVE_IFPACK_AZTECOO
  Teuchos::RCP<AztecOO> AztecSolver_;
#endif

  // Inner preconditioner
  Teuchos::RCP<Ifpack_Preconditioner> IfpackPrec_;

};


#endif // IFPACK_KRYLOV_H
