/*
* <moeoParetoObjectiveVectorComparator.h>
* Copyright (C) DOLPHIN Project-Team, INRIA Futurs, 2006-2007
* (C) OPAC Team, LIFL, 2002-2007
*
* Arnaud Liefooghe
*
* This software is governed by the CeCILL license under French law and
* abiding by the rules of distribution of free software.  You can  use,
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* "http://www.cecill.info".
*
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* modify and redistribute granted by the license, users are provided only
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* economic rights,  and the successive licensors  have only  limited liability.
*
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*/
//-----------------------------------------------------------------------------

#ifndef MOEOPARETOOBJECTIVEVECTORCOMPARATOR_H_
#define MOEOPARETOOBJECTIVEVECTORCOMPARATOR_H_

#include <comparator/moeoObjectiveVectorComparator.h>

/**
 * This functor class allows to compare 2 objective vectors according to Pareto dominance.
 */
template < class ObjectiveVector >
class moeoParetoObjectiveVectorComparator : public moeoObjectiveVectorComparator < ObjectiveVector >
  {
  public:

    /**
     * Returns true if _objectiveVector1 is dominated by _objectiveVector2
     * @param _objectiveVector1 the first objective vector
     * @param _objectiveVector2 the second objective vector	
     */
    bool operator()(const ObjectiveVector & _objectiveVector1, const ObjectiveVector & _objectiveVector2)
    {
      bool dom = false;
      for (unsigned int i=0; i<ObjectiveVector::nObjectives(); i++)
        {
          // first, we have to check if the 2 objective values are not equal for the ith objective
          if ( fabs(_objectiveVector1[i] - _objectiveVector2[i]) > ObjectiveVector::Traits::tolerance() )
            {
              // if the ith objective have to be minimized...
              if (ObjectiveVector::minimizing(i))
                {
                  if (_objectiveVector1[i] > _objectiveVector2[i])
                    {
                      dom = true;		//_objectiveVector1[i] is not better than _objectiveVector2[i]
                    }
                  else
                    {
                      return false;	//_objectiveVector2 cannot dominate _objectiveVector1
                    }
                }
              // if the ith objective have to be maximized...
              else if (ObjectiveVector::maximizing(i))
                {
                  if (_objectiveVector1[i] < _objectiveVector2[i])
                    {
                      dom = true;		//_objectiveVector1[i] is not better than _objectiveVector2[i]
                    }
                  else
                    {
                      return false;	//_objectiveVector2 cannot dominate _objectiveVector1
                    }
                }
            }
        }
      return dom;
    }

  };

#endif /*MOEOPARETOOBJECTIVEVECTORCOMPARATOR_H_*/
