paradiseo/branches/paradiseo-moeo-1.0/src/moeoArchive.h

// -*- mode: c++; c-indent-level: 4; c++-member-init-indent: 8; comment-column: 35; -*-

//-----------------------------------------------------------------------------
// moeoArchive.h
// (c) OPAC Team (LIFL), Dolphin Project (INRIA), 2007
/*
    This library...

    Contact: paradiseo-help@lists.gforge.inria.fr, http://paradiseo.gforge.inria.fr
 */
//-----------------------------------------------------------------------------

#ifndef MOEOARCHIVE_H_
#define MOEOARCHIVE_H_

#include <eoPop.h>

/**
 * An archive is a secondary population that stores non-dominated solutions
 */
template < class MOEOT > class moeoArchive:public eoPop < MOEOT >
{
public:

  using std::vector < MOEOT >::size;
  using std::vector < MOEOT >::operator[];
  using std::vector < MOEOT >::back;
  using std::vector < MOEOT >::pop_back;


	/**
	 * The type of an objective vector for a solution
	 */
  typedef typename MOEOT::ObjectiveVector ObjectiveVector;


	/**
	 * Default ctor.
	 * The moeoObjectiveVectorComparator used to compare solutions is based on Pareto dominance
	 */
moeoArchive ():eoPop < MOEOT > (), comparator (paretoComparator)
  {
  }


	/**
	 * Ctor
	 * @param _comparator the moeoObjectiveVectorComparator used to compare solutions
	 */
moeoArchive (moeoObjectiveVectorComparator < ObjectiveVector > &_comparator):eoPop < MOEOT > (),
    comparator
    (_comparator)
  {
  }


	/**
	 * Returns true if the current archive dominates _objectiveVector according to the moeoObjectiveVectorComparator given in the constructor
	 * @param _objectiveVector the objective vector to compare with the current archive
	 */
  bool dominates (const ObjectiveVector & _objectiveVector) const
  {
    for (unsigned i = 0; i < size (); i++)
      {
	if (comparator (operator[](i).fitness (), _objectiveVector) == 1)
	  {
	    return true;
	  }
      }
    return false;
  }


	/**
	 * Returns true if the current archive already contains a solution with the same objective values than _objectiveVector
	 * @param _objectiveVector the objective vector to compare with the current archive
	 */
  bool contains (const ObjectiveVector & _objectiveVector) const
  {
    for (unsigned i = 0; i < size; i++)
      {
	if (operator[](i).fitness () == _objectiveVector)
	  {
	    return true;
	  }
      }
    return false;
  }


	/**
	 * Updates the archive with a given individual _moeo
	 * @param _moeo the given individual
	 */
  void update (const MOEOT & _moeo)
  {
    // first step: removing the dominated solutions from the archive
    for (unsigned j = 0; j < size ();)
      {
	// if _moeo.fitness() dominates operator[](j).fitness()
	//if ( comparator(_moeo.fitness(), operator[](j).fitness())==1 )
	if (comparator
	    (_moeo.objectiveVector (), operator[](j).objectiveVector ()) == 1)
	  {
	    operator[](j) = back ();
	    pop_back ();
	  }
	//else if (_moeo.fitness() == operator[](j).fitness())
	else if (_moeo.objectiveVector () == operator[](j).objectiveVector ())
	  {
	    operator[](j) = back ();
	    pop_back ();
	  }
	else
	  {
	    j++;
	  }
      }
    // second step: is _moeo dominated?
    bool dom = false;
    for (unsigned j = 0; j < size (); j++)
      {
	// if operator[](j).fitness() dominates _moeo.fitness()
	//if ( comparator(operator[](j).fitness(), _moeo.fitness())==1 )
	if (comparator
	    (operator[](j).objectiveVector (), _moeo.objectiveVector ()) == 1)
	  {
	    dom = true;
	    break;
	  }
      }
    if (!dom)
      {
	push_back (_moeo);
      }
  }


	/**
	 * Updates the archive with a given population _pop
	 * @param _pop the given population
	 */
  void update (const eoPop < MOEOT > &_pop)
  {
    for (unsigned i = 0; i < _pop.size (); i++)
      {
	update (_pop[i]);
      }
  }


private:

	/** The moeoObjectiveVectorComparator used to compare solutions */
  moeoObjectiveVectorComparator < ObjectiveVector > &comparator;
	/** A moeoObjectiveVectorComparator	based on Pareto dominance (used as default) */
  moeoParetoObjectiveVectorComparator < ObjectiveVector > paretoComparator;

};

#endif /*MOEOARCHIVE_H_ */