git-svn-id: svn://scm.gforge.inria.fr/svnroot/paradiseo@177 331e1502-861f-0410-8da2-ba01fb791d7f

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

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+// -*- mode: c++; c-indent-level: 4; c++-member-init-indent: 8; comment-column: 35; -*-
+
+//-----------------------------------------------------------------------------
+// moeoObjectiveVectorComparator.h
+// (c) OPAC Team (LIFL), Dolphin Project (INRIA), 2007
+/*
+    This library...
+
+    Contact: paradiseo-help@lists.gforge.inria.fr, http://paradiseo.gforge.inria.fr
+ */
+//-----------------------------------------------------------------------------
+
+#ifndef MOEOOBJECTIVEVECTORCOMPARATOR_H_
+#define MOEOOBJECTIVEVECTORCOMPARATOR_H_
+
+#include <math.h>
+#include <eoFunctor.h>
+
+/**
+ * Abstract class allowing to compare 2 objective vectors.
+ * The template argument ObjectiveVector have to be a moeoObjectiveVector. 
+ */
+template < class ObjectiveVector >
+class moeoObjectiveVectorComparator : public eoBF < const ObjectiveVector &, const ObjectiveVector &, int >
+{};
+
+
+/**
+ * This functor class allows to compare 2 objective vectors according to Pareto dominance
+ */
+template < class ObjectiveVector >
+class moeoParetoObjectiveVectorComparator : public moeoObjectiveVectorComparator < ObjectiveVector >
+{
+public:
+	
+	/**
+	 * Returns 1 if _objectiveVector1 dominates _objectiveVector2, -1 if _objectiveVector2 dominates _objectiveVector1 and 0 if no one dominates the other
+	 * @param _objectiveVector1 the first objective vector
+	 * @param _objectiveVector2 the second objective vector	  
+	 */	 
+	int operator()(const ObjectiveVector & _objectiveVector1, const ObjectiveVector & _objectiveVector2)
+	{
+		bool dom1 = false;
+		bool dom2 = false;
+		for (unsigned 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])
+					{
+						dom2 = true;	//_objectiveVector2[i] is better than _objectiveVector1[i]
+					}
+					else				// _objectiveVector1[i] < _objectiveVector2[i]
+					{
+						dom1 = true;	//_objectiveVector1[i] is better than _objectiveVector2[i]
+					}
+				}
+				// if the ith objective have to be maximized...
+				else if (ObjectiveVector::maximizing(i))
+				{
+					if (_objectiveVector1[i] > _objectiveVector2[i])
+					{
+						dom1 = true;	//_objectiveVector1[i] is better than _objectiveVector2[i]						
+					}
+					else				// _objectiveVector1[i] < _objectiveVector2[i]
+					{
+						dom2 = true;	//_objectiveVector2[i] is better than _objectiveVector1[i]
+					}
+				}
+			}
+		}
+		if (dom1 == dom2)
+		{
+			return 0;	// no one dominates the other
+		}
+		if (dom1)
+		{
+			return 1;	//_objectiveVector1 dominates _objectiveVector2
+		}
+		return -1;		//_objectiveVector2 dominates _objectiveVector1
+	}   
+
+};
+
+#endif /*MOEOOBJECTIVEVECTORCOMPARATOR_H_*/