git-svn-id: svn://scm.gforge.inria.fr/svnroot/paradiseo@190 331e1502-861f-0410-8da2-ba01fb791d7f

branches/paradiseo-moeo-1.0/src/moeoRouletteSelect.h/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_ */