Ifpack_OverlappingPartitioner.h

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#ifndef IFPACK_OVERLAPPINGPARTITIONER_H
#define IFPACK_OVERLAPPINGPARTITIONER_H

#include "Ifpack_ConfigDefs.h"
#include "Ifpack_Partitioner.h"
#include "Teuchos_ParameterList.hpp"
class Epetra_Comm;
class Ifpack_Graph;
class Epetra_Map;
class Epetra_BlockMap;
class Epetra_Import;

/* \brief Ifpack_OverlappingPartitioner: A class to create overlapping
    partitions of a local graph.

Class Ifpack_OverlappingPartitioner enables the extension of
non-overlapping partitions to an arbitrary value of overlap.
Note that overlap refers to the overlap among \e local parts,
and not the overlap among the processes.

Supported parameters are:
- \c "partitioner: local parts": the required number of parts;
- \c "partitioner: overlap": the required amount of overlap is set in
  parameter. Default = 0 (integer).
- \c "partitioner: verbose": if \c true, information are reported on
  cout. Nothing is reported otherwise.

This class is a semi-virtual class, that contains the basic utilities
for derived classes Ifpack_LinearPartitioner, Ifpack_GreedyPartitioner,
Ifpack_METISPartitioner, and Ifpack_EquationPartitioner. Graphs in
input to one of these classes are supposed to contain no singletons.
Usually, this means that the graph is derived from an Epetra_RowMatrix,
that has been filtered using Ifpack_SingletonFilter.

\author Marzio Sala, SNL 9214.

\date Last update: Oct-04.
*/
class Ifpack_OverlappingPartitioner : public Ifpack_Partitioner {

public:

  Ifpack_OverlappingPartitioner(const Ifpack_Graph* Graph);

  virtual ~Ifpack_OverlappingPartitioner();

  int NumLocalParts() const
  {
    return(NumLocalParts_);
  }

  int OverlappingLevel() const
  {
    return(OverlappingLevel_);
  }


  int operator() (int MyRow) const
  {
    if ((MyRow < 0) || (MyRow > NumMyRows()))
      IFPACK_CHK_ERR(-1); // input value not valid

    return(Partition_[MyRow]);
  }

  int operator() (int i, int j) const
  {
    if ((i < 0) || (i >= NumLocalParts()))
      IFPACK_CHK_ERR(-1);

    if ((j < 0) || (j > (int)Parts_[i].size()))
      IFPACK_CHK_ERR(-2);

    return(Parts_[i][j]);
  }

  inline int NumRowsInPart(const int Part) const
  {
    return(Parts_[Part].size());
  }

  int RowsInPart(const int Part, int* List) const
  {
    for (int i = 0 ; i < NumRowsInPart(Part) ; ++i)
      List[i] = Parts_[Part][i];

    return(0);
  }

  const int* NonOverlappingPartition() const
  {
    return(&Partition_[0]);
  }


  virtual int SetParameters(Teuchos::ParameterList& List);


  virtual int SetPartitionParameters(Teuchos::ParameterList& List) = 0;

  virtual int Compute();

  virtual int ComputePartitions() = 0;

  virtual int ComputeOverlappingPartitions();

  bool IsComputed()
  {
    return(IsComputed_);
  }

  virtual std::ostream& Print(std::ostream& os) const;

protected:

  int NumMyRows() const;
  int NumMyNonzeros() const;
#ifndef EPETRA_NO_32BIT_GLOBAL_INDICES
  int NumGlobalRows() const;
#endif
  long long NumGlobalRows64() const;
  int MaxNumEntries() const;
  const Epetra_Comm& Comm() const;
  int NumLocalParts_;
  std::vector<int> Partition_;
  // partition i
  std::vector<std::vector<int> > Parts_;
  const Ifpack_Graph* Graph_;
  int OverlappingLevel_;
  bool IsComputed_;
  bool verbose_;

}; // class Ifpack_Partitioner

#endif // IFPACK_OVERLAPPINGPARTITIONER_H