diff --git a/branches/paradiseo-moeo-1.0/src/metric/moeoHypervolumeBinaryMetric.h b/branches/paradiseo-moeo-1.0/src/metric/moeoHypervolumeBinaryMetric.h new file mode 100644 index 000000000..d0d01fb34 --- /dev/null +++ b/branches/paradiseo-moeo-1.0/src/metric/moeoHypervolumeBinaryMetric.h @@ -0,0 +1,139 @@ +// -*- mode: c++; c-indent-level: 4; c++-member-init-indent: 8; comment-column: 35; -*- + +//----------------------------------------------------------------------------- +// moeoHypervolumeBinaryMetric.h +// (c) OPAC Team (LIFL), Dolphin Project (INRIA), 2007 +/* + This library... + + Contact: paradiseo-help@lists.gforge.inria.fr, http://paradiseo.gforge.inria.fr + */ +//----------------------------------------------------------------------------- + +#ifndef MOEOHYPERVOLUMEBINARYMETRIC_H_ +#define MOEOHYPERVOLUMEBINARYMETRIC_H_ + +#include +#include + +/** + * Hypervolume binary metric allowing to compare two objective vectors as proposed in + * Zitzler E., Künzli S.: Indicator-Based Selection in Multiobjective Search. In Parallel Problem Solving from Nature (PPSN VIII). + * Lecture Notes in Computer Science 3242, Springer, Birmingham, UK pp.832–842 (2004). + * This indicator is based on the hypervolume concept introduced in + * Zitzler, E., Thiele, L.: Multiobjective Optimization Using Evolutionary Algorithms - A Comparative Case Study. + * Parallel Problem Solving from Nature (PPSN-V), pp.292-301 (1998). + */ +template < class ObjectiveVector > +class moeoHypervolumeBinaryMetric : public moeoNormalizedSolutionVsSolutionBinaryMetric < ObjectiveVector, double > +{ +public: + + /** + * Ctor + * @param _rho value used to compute the reference point from the worst values for each objective (default : 1.1) + */ + moeoHypervolumeBinaryMetric(double _rho = 1.1) : rho(_rho) + { + // not-a-maximization problem check + for (unsigned i=0; i :: bounds; + /** Functor to compare two objective vectors according to Pareto dominance relation */ + moeoParetoObjectiveVectorComparator < ObjectiveVector > paretoComparator; + + /** + * Returns the volume of the space that is dominated by _o2 but not by _o1 with respect to a reference point computed using rho for the objective _obj. + * @param _o1 the first objective vector + * @param _o2 the second objective vector + * @param _obj the objective index + * @param _flag used for iteration, if _flag=true _o2 is not talen into account (default : false) + */ + double hypervolume(const ObjectiveVector & _o1, const ObjectiveVector & _o2, const unsigned _obj, const bool _flag = false) + { + double result; + double range = rho * bounds[_obj].range(); + double max = bounds[_obj].minimum() + range; + // value of _1 for the objective _obj + double v1 = _o1[_obj]; + // value of _2 for the objective _obj (if _flag=true, v2=max) + double v2; + if (_flag) + { + v2 = max; + } + else + { + v2 = _o2[_obj]; + } + // computation of the volume + if (_obj == 0) + { + if (v1 < v2) + { + result = (v2 - v1) / range; + } + else + { + result = 0; + } + } + else + { + if (v1 < v2) + { + result = ( hypervolume(_o1, _o2, _obj-1, true) * (v2 - v1) / range ) + ( hypervolume(_o1, _o2, _obj-1) * (max - v2) / range ); + } + else + { + result = hypervolume(_o1, _o2, _obj-1) * (max - v2) / range; + } + } + return result; + } + +}; + +#endif /*MOEOHYPERVOLUMEBINARYMETRIC_H_*/