ga.h

/***************************************************************************
 *   Copyright (C) Anders Larsen                                           *
 *   anders.larsen@spray.se                                                *
 *                                                                         *
 *   Use of a Genetic Algoritm to solve a Traveling Salesman Problem.      *
 *   The code can easily be adapted to other types problems as long as     *
 *   solutions  can be expressed as fixed length arrays of integers.       *
 *                                                                         *
 *   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     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   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.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/
 
// A class to create and submit a population of solutions to a genetic evolution

#ifndef GA_H
#define GA_H

#include "tsp.h"
#include <utility>
#include <vector>
#include <map>

typedef std::map<double, Sol> Pop;
typedef std::map<double, Sol>::iterator PopIter;

/* For multimap use:
typedef std::multimap<double, Sol> Pop;
typedef std::multimap<double, Sol>::iterator PopIter;
*/

class Ga {
   Pop oldPop;
   Pop newPop;
   Problem *problem;
   double selPres, mutFreq;
   int popSize;
   int newPopSize;
   int elitism;
   unsigned long crossovers;

public:

   // Create a population, based on some problem type
   Ga(Problem *pr, int ps = 200, int e = 1, double sp = 2, double mf = 0.01);
   
   // Evolve the next generation
   void generation(void);
   
   // Change the selection pressure
   void setSelPres(double p)  { selPres = p; };
   
   // Change the mutation frequency
   void setMutFreq(double f)  { mutFreq = f; };
   
   // Change level ov elitism (number of the best solutions to move to next)
   void setElitism(int e)     { elitism = e; };
   
   // Change the population size
   void setPopSize(int p)     { newPopSize = p; };
   
   // Iterator to the first solution in the population
   PopIter begin(void)        { return newPop.begin(); };
   
   // Iterator to the last + 1 solution in the population
   PopIter end(void)          { return newPop.end(); };
   
   // Get the current populationsize
   int size(void)             { return newPop.size(); };
   
   // Get a count of crossovers done so far
   unsigned long getCrossovers(void) { return crossovers; };
};

#endif