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#ifndef IFPACK_SILU_H
#define IFPACK_SILU_H

#include "Ifpack_ConfigDefs.h"

#ifdef HAVE_IFPACK_SUPERLU
#include "Ifpack_Preconditioner.h"
#include "Ifpack_Condest.h"
#include "Ifpack_ScalingType.h"
#include "Ifpack_IlukGraph.h"
#include "Epetra_CompObject.h"
#include "Epetra_MultiVector.h"
#include "Epetra_Vector.h"
#include "Epetra_CrsGraph.h"
#include "Epetra_CrsMatrix.h"
#include "Epetra_BlockMap.h"
#include "Epetra_Map.h"
#include "Epetra_Object.h"
#include "Epetra_Comm.h"
#include "Epetra_RowMatrix.h"
#include "Epetra_Time.h"
#include "Teuchos_RefCountPtr.hpp"

namespace Teuchos {
  class ParameterList;
}

// SuperLU includes
#include "slu_ddefs.h"


/*! @class Ifpack_SILU
    @brief A wrapper to SuperLU 4.0's supernodal ILUT w/ partial pivoting.

    The Ifpack_SILU class is a  wrapper to SuperLU 4.0's supernodal ILUT w/ partial pivoting.

    \author Chris Siefert, SNL 1431
    \date Last modified on 07-Apr-10
*/    

class Ifpack_SILU: public Ifpack_Preconditioner {
      
public:
  /// @name Constructors and destructors.
  //@{
  //! Constructor
  Ifpack_SILU(Epetra_RowMatrix* A);
  
  //! Destructor
  ~Ifpack_SILU()
  {
    Destroy();
  }

  //@}
  /// @name Construction methods
  //@{
  
  //! Initialize the preconditioner, does not touch matrix values.
  int Initialize();
  
  //! Returns \c true if the preconditioner has been successfully initialized.
  bool IsInitialized() const
  {
    return(IsInitialized_);
  }

  //! Compute ILU factors L and U using the specified graph, diagonal perturbation thresholds and relaxation parameters.
  int Compute();

  //! If factor is completed, this query returns true, otherwise it returns false.
  bool IsComputed() const 
  {
    return(IsComputed_);
  }

  //! Set parameters using a Teuchos::ParameterList object.
  /* This method is only available if the Teuchos package is enabled.
     This method recognizes four parameter names: relax_value,
     absolute_threshold, relative_threshold and overlap_mode. These names are
     case insensitive, and in each case except overlap_mode, the ParameterEntry
     must have type double. For overlap_mode, the ParameterEntry must have
     type Epetra_CombineMode.
  */
  int SetParameters(Teuchos::ParameterList& parameterlist);

  //! If set true, transpose of this operator will be applied.
  /*! This flag allows the transpose of the given operator to be used implicitly.  Setting this flag
      affects only the Apply() and ApplyInverse() methods.  If the implementation of this interface 
      does not support transpose use, this method should return a value of -1.
      
      \param
       UseTranspose_in - (In) If true, multiply by the transpose of operator, otherwise just use operator.

      \return Always returns 0.
  */
  int SetUseTranspose(bool UseTranspose_in) {UseTranspose_ = UseTranspose_in; return(0);};
  //@}

  /// @name Mathematical functions.
  //@{
  // Applies the matrix to X, returns the result in Y.
  int Apply(const Epetra_MultiVector& X, 
	       Epetra_MultiVector& Y) const
  {
    return(Multiply(false,X,Y));
  }

  int Multiply(bool Trans, const Epetra_MultiVector& X, 
	       Epetra_MultiVector& Y) const;

  //! Returns the result of a Epetra_Operator inverse applied to an Epetra_MultiVector X in Y.
  /*! In this implementation, we use several existing attributes to determine how virtual
      method ApplyInverse() should call the concrete method Solve().  We pass in the UpperTriangular(), 
      the Epetra_CrsMatrix::UseTranspose(), and NoDiagonal() methods. The most notable warning is that
      if a matrix has no diagonal values we assume that there is an implicit unit diagonal that should
      be accounted for when doing a triangular solve.

    \param 
	   X - (In) A Epetra_MultiVector of dimension NumVectors to solve for.
    \param Out
	   Y - (Out) A Epetra_MultiVector of dimension NumVectors containing result.

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

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

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

  //@}

  /// @name Query methods
  //@{
  
  //! Returns a character string describing the operator
  const char* Label() const {return(Label_);}

  //! Sets label for \c this object.
  int SetLabel(const char* Label_in)
  {
    strcpy(Label_,Label_in);
    return(0);
  }
  
  //! Returns 0.0 because this class cannot compute Inf-norm.
  double NormInf() const {return(0.0);};

  //! Returns false because this class cannot compute an Inf-norm.
  bool HasNormInf() const {return(false);};

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

  //! Returns the Epetra_Map object associated with the domain of this operator.
  const Epetra_Map & OperatorDomainMap() const {return(A_->OperatorDomainMap());};

  //! Returns the Epetra_Map object associated with the range of this operator.
  const Epetra_Map & OperatorRangeMap() const{return(A_->OperatorRangeMap());};

  //! Returns the Epetra_BlockMap object associated with the range of this matrix operator.
  const Epetra_Comm & Comm() const{return(Comm_);};

  //! Returns a reference to the matrix to be preconditioned.
  const Epetra_RowMatrix& Matrix() const
  { 
    return(*A_);
  }

  //! Prints on stream basic information about \c this object.
  virtual ostream& Print(ostream& os) const;

  //! 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_);
  }

  virtual double InitializeFlops() const
  {
    return(0.0);
  }

  virtual double ComputeFlops() const
  {
    return(0.0);
  }

  virtual double ApplyInverseFlops() const
  {
    return(0.0);
  }

private:

  //@}
  /// @name Private methods
  //@{

  //! Copy constructor (should never be used)
  Ifpack_SILU(const Ifpack_SILU& RHS):
    Comm_(RHS.Comm()),
    Time_(RHS.Comm())
  {}

  //! operator= (should never be used)
  Ifpack_SILU& operator=(const Ifpack_SILU& RHS)
  {
    return(*this);
  }

  //! Destroys all internal data
  void Destroy();

  //! Returns the result of a Ifpack_ILU forward/back solve on a Epetra_MultiVector X in Y.
  /*! 
    \param In
    Trans -If true, solve transpose problem.
    \param 
    X - (In) A Epetra_MultiVector of dimension NumVectors to solve for.
    \param Out
    Y - (Out) A Epetra_MultiVector of dimension NumVectorscontaining result.
    
    \return Integer error code, set to 0 if successful.
  */
  int Solve(bool Trans, const Epetra_MultiVector& X, Epetra_MultiVector& Y) const;

  int InitAllValues(const Epetra_RowMatrix & A, int MaxNumEntries);

  //! Get relative threshold value
  double DropTol() const {return DropTol_;}

  //! Get Fill Tolerance (pivoting perturbation)
  double FillTol() const{return FillTol_;}

  //! Get Fill Factor
  double FillFactor() const{return FillFactor_;}

  //! Get Drop Rule
  int DropRule() const{return DropRule_;}

#ifndef EPETRA_NO_32BIT_GLOBAL_INDICES
  //! Returns the number of global matrix rows.
  int NumGlobalRows() const {return(Graph().NumGlobalRows());};
  
  //! Returns the number of global matrix columns.
  int NumGlobalCols() const {return(Graph().NumGlobalCols());};
  
  //! Returns the number of nonzero entries in the global graph.
  int NumGlobalNonzeros() const {return(Graph().NumGlobalNonzeros());};
  
  //! Returns the number of diagonal entries found in the global input graph.
  virtual int NumGlobalBlockDiagonals() const {return(Graph().NumGlobalBlockDiagonals());};
#endif

  //! Returns the number of global matrix rows.
  long long NumGlobalRows64() const {return(Graph().NumGlobalRows64());};
  
  //! Returns the number of global matrix columns.
  long long NumGlobalCols64() const {return(Graph().NumGlobalCols64());};
  
  //! Returns the number of nonzero entries in the global graph.
  long long NumGlobalNonzeros64() const {return(Graph().NumGlobalNonzeros64());};
  
  //! Returns the number of diagonal entries found in the global input graph.
  virtual long long NumGlobalBlockDiagonals64() const {return(Graph().NumGlobalBlockDiagonals64());};

  //! Returns the number of local matrix rows.
  int NumMyRows() const {return(Graph().NumMyRows());};
  
  //! Returns the number of local matrix columns.
  int NumMyCols() const {return(Graph().NumMyCols());};
  
  //! Returns the number of nonzero entries in the local graph.
  int NumMyNonzeros() const {return(Graph().NumMyNonzeros());};
  
  //! Returns the number of diagonal entries found in the local input graph.
  virtual int NumMyBlockDiagonals() const {return(Graph().NumMyBlockDiagonals());};
  
  //! Returns the number of nonzero diagonal values found in matrix.
  virtual int NumMyDiagonals() const {return(NumMyDiagonals_);};
  
#ifndef EPETRA_NO_32BIT_GLOBAL_INDICES
  //! Returns the index base for row and column indices for this graph.
  int IndexBase() const {return(Graph().IndexBase());};
#endif
  long long IndexBase64() const {return(Graph().IndexBase64());};

  //! Returns the address of the Epetra_CrsGraph associated with this factored matrix.
  const Epetra_CrsGraph & Graph() const {return(*Graph_);};
  
  //! Returns a reference to the matrix.
  Epetra_RowMatrix& Matrix()
  {
    return(*A_);
  }

  //@}

  /// @name Internal data
  //@{
  
  //! Pointer to the Epetra_RowMatrix to factorize
  Teuchos::RefCountPtr<Epetra_RowMatrix> A_;
  Teuchos::RefCountPtr<Epetra_CrsGraph> Graph_;
  Teuchos::RefCountPtr<Epetra_Map> IlukRowMap_;
  Teuchos::RefCountPtr<Epetra_Map> IlukDomainMap_;
  Teuchos::RefCountPtr<Epetra_Map> IlukRangeMap_;
  const Epetra_Comm & Comm_;
  //! Contains the Overlapped Matrix
  Teuchos::RefCountPtr<Epetra_CrsMatrix> Aover_;
  bool UseTranspose_;

  int NumMyDiagonals_;
  bool Allocated_;
  bool ValuesInitialized_;
  bool Factored_;

  //! Drop Tolerance
  double DropTol_;
  //! Fill Tolerance
  double FillTol_;
  //! Fill Factor
  double FillFactor_;
  //! Drop Rule
  int DropRule_;

  //! condition number estimate
  double Condest_;
  //! If \c true, the preconditioner has been successfully initialized.
  bool IsInitialized_;
  //! If \c true, the preconditioner has been successfully computed.
  bool IsComputed_;
  //! Label of \c this object.
  char Label_[160];
  //! 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_;
  //! Used for timing issues
  mutable Epetra_Time Time_;
  //! SuperLU stats
  mutable SuperLUStat_t stat_;
  //! SuperLU options
  mutable superlu_options_t options_;
  //! SuperLU matrix wrappers
  mutable SuperMatrix SA_,SAc_,SL_,SU_,SY_;
  //! SuperLU goodies
  int *etree_,*perm_r_,*perm_c_;
  //@}


  template<typename int_type>
  int TInitialize();
};

#endif /* HAVE_IFPACK_SUPERLU */
#endif /* IFPACK_ILU_H */
