add comparator

git-svn-id: svn://scm.gforge.inria.fr/svnroot/paradiseo@371 331e1502-861f-0410-8da2-ba01fb791d7f

branches/paradiseo-moeo-1.0/src/comparator/moeoAggregativeComparator.h

@@ -0,0 +1,55 @@
+// -*- mode: c++; c-indent-level: 4; c++-member-init-indent: 8; comment-column: 35; -*-
+
+//-----------------------------------------------------------------------------
+// moeoAggregativeComparator.h
+// (c) OPAC Team (LIFL), Dolphin Project (INRIA), 2007
+/*
+    This library...
+
+    Contact: paradiseo-help@lists.gforge.inria.fr, http://paradiseo.gforge.inria.fr
+ */
+//-----------------------------------------------------------------------------
+
+#ifndef MOEOAGGREGATIVECOMPARATOR_H_
+#define MOEOAGGREGATIVECOMPARATOR_H_
+
+#include <comparator/moeoComparator.h>
+
+/**
+ * Functor allowing to compare two solutions according to their fitness and diversity values, each according to its aggregative value.
+ */
+template < class MOEOT >
+class moeoAggregativeComparator : public moeoComparator < MOEOT >
+{
+public:
+
+    /**
+     * Ctor.
+     * @param _weightFitness the weight for fitness
+     * @param _weightDiversity the weight for diversity
+     */
+    moeoAggregativeComparator(double _weightFitness = 1.0, double _weightDiversity = 1.0) : weightFitness(_weightFitness), weightDiversity(_weightDiversity)
+    {}
+
+
+    /**
+     * Returns true if _moeo1 < _moeo2 according to the aggregation of their fitness and diversity values
+     * @param _moeo1 the first solution
+     * @param _moeo2 the second solution
+     */
+    const bool operator()(const MOEOT & _moeo1, const MOEOT & _moeo2)
+    {
+        return ( weightFitness * _moeo1.fitness() + weightDiversity * _moeo1.diversity() ) < ( weightFitness * _moeo2.fitness() + weightDiversity * _moeo2.diversity() );
+    }
+
+
+private:
+
+    /** the weight for fitness */
+    double weightFitness;
+    /** the weight for diversity */
+    double weightDiversity;
+
+};
+
+#endif /*MOEOAGGREGATIVECOMPARATOR_H_*/