RandomSelectStrategy.h

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/***************************************************************************
 *   Copyright (C) 2008-2011 LpzRobots development team                    *
 *    Joerg Weider   <joergweide84 at aol dot com> (robot12)               *
 *    Georg Martius  <georg dot martius at web dot de>                     *
 *    Frank Guettler <guettler at informatik dot uni-leipzig dot de        *
 *    Frank Hesse    <frank at nld dot ds dot mpg dot de>                  *
 *    Ralf Der       <ralfder at mis dot mpg dot de>                       *
 *    Joern Hoffmann <jhoffmann at informatik dot uni-leipzig dot de       *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
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 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
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 *   You should have received a copy of the GNU General Public License     *
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 *   Free Software Foundation, Inc.,                                       *
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 ***************************************************************************/

#ifndef RANDOMSELECTSTRATEGY_H_
#define RANDOMSELECTSTRATEGY_H_

//includes
#include <selforg/randomgenerator.h>

//forward declaration
class Generation;

//ga_tools includes
#include "ISelectStrategy.h"

/**
 * This class makes a select by randomized comparison of one individual of the old generation
 * with a random number. If it lost, so it dosn't comes in the next generation. If enough
 * individual "killed", comes the living in the next generation.
 *
 * With this method it is possible that a bad individual comes in the next generation. So you dosn't
 * becomes a to elite generation and save some alternatives in the gens.
 * This way is in this point better than the EliteSelectStrategy. But worse than the TournamentSelectStrategy.
 */
class RandomSelectStrategy :public ISelectStrategy {
public:
        /**
         * constructor
         * @param random (RandGen*) a random generator. Is needed for the <<<randomized>>> comparison
         */
        RandomSelectStrategy(RandGen* random);

        /**
         * default destructor
         */
        virtual ~RandomSelectStrategy();

        /**
         * implementation for the interface ISelectStrategy
         * @param oldGeneration (Generation*) the old generation
         * @param newGeneration (Generation*) the next generation
         */
        virtual void select(Generation* oldGeneration, Generation* newGeneration);

protected:
        /**
         * the random generator
         */
        RandGen* m_random;

private:
        /**
         * disable the default constructor.
         */
        RandomSelectStrategy();
};

#endif /* RANDOMSELECTSTRATEGY_H_ */