eoSGA.h

// -*- mode: c++; c-indent-level: 4; c++-member-init-indent: 8; comment-column: 35; -*-

//-----------------------------------------------------------------------------
// eoSGA.h
// (c) GeNeura Team, 2000 - EEAAX 1999 - Maarten Keijzer 2000
/*
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library 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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    Contact: todos@geneura.ugr.es, http://geneura.ugr.es
             Marc.Schoenauer@polytechnique.fr
             mak@dhi.dk
 */
//-----------------------------------------------------------------------------

#ifndef _eoSGA_h
#define _eoSGA_h

#include <eoInvalidateOps.h>
#include <eoContinue.h>
#include <eoPop.h>
#include <eoSelectOne.h>
#include <eoSelectPerc.h>
#include <eoEvalFunc.h>
#include <eoAlgo.h>
#include <apply.h>

template <class EOT>
class eoSGA : public eoAlgo<EOT>
{
public :

  // added this second ctor as I didn't like the ordering of the parameters
  // in the one above. Any objection :-) MS
  eoSGA(
        eoSelectOne<EOT>& _select,
        eoQuadOp<EOT>& _cross, float _crate,
        eoMonOp<EOT>& _mutate, float _mrate,
        eoEvalFunc<EOT>& _eval,
        eoContinue<EOT>& _cont)
    : cont(_cont),
          mutate(_mutate),
          mutationRate(_mrate),
          cross(_cross),
          crossoverRate(_crate),
          select(_select),
          eval(_eval) {}

  void operator()(eoPop<EOT>& _pop)
  {
    eoPop<EOT> offspring;

    do
      {
        select(_pop, offspring);

        unsigned i;

        for (i=0; i<_pop.size()/2; i++)
          {
            if ( rng.flip(crossoverRate) )
            {
                    // this crossover generates 2 offspring from two parents
                    if (cross(offspring[2*i], offspring[2*i+1]))
        {
          offspring[2*i].invalidate();
          offspring[2*i+1].invalidate();
        }
      }
          }

        for (i=0; i < offspring.size(); i++)
          {
            if (rng.flip(mutationRate) )
            {
                     if (mutate(offspring[i]))
          offspring[i].invalidate();
            }
          }

        _pop.swap(offspring);
        apply<EOT>(eval, _pop);

      } while (cont(_pop));
  }

private :

  eoContinue<EOT>& cont;
  eoInvalidateMonOp<EOT> mutate;
  float mutationRate;
  // eoInvalidateQuadOp invalidates the embedded operator
  eoInvalidateQuadOp<EOT> cross;
  float crossoverRate;
  eoSelectPerc<EOT> select;
  eoEvalFunc<EOT>& eval;
};

#endif