eoSequentialSelect.h

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

//-----------------------------------------------------------------------------
// eoSequential.h
// (c) GeNeura Team, 1998 - Maarten Keijzer 2000, Marc Schoenauer, 2002
/*
    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 eoSequential_h
#define eoSequential_h

#include <limits>

#include "utils/eoData.h"
#include "utils/eoRNG.h"
#include "eoSelectOne.h"

template <class EOT> class eoSequentialSelect: public eoSelectOne<EOT>
{
 public:
  eoSequentialSelect(bool _ordered = true)
        : ordered(_ordered), current(std::numeric_limits<unsigned>::max()) {}

  void setup(const eoPop<EOT>& _pop)
  {
    eoPters.resize(_pop.size());
    if (ordered)    // probably we could have a marker to avoid re-sorting
            _pop.sort(eoPters);
    else
      _pop.shuffle(eoPters);
    current=0;
  }

  virtual const EOT& operator()(const eoPop<EOT>& _pop)
  {
    if (current >= _pop.size())
      setup(_pop);

    unsigned eoN = current;
    current++;
    return *eoPters[eoN] ;
  }
private:
  bool ordered;
  unsigned current;
  std::vector<const EOT*> eoPters;
};



template <class EOT> class eoEliteSequentialSelect: public eoSelectOne<EOT>
{
 public:

  eoEliteSequentialSelect(): current(std::numeric_limits<unsigned>::max()) {}

  void setup(const eoPop<EOT>& _pop)
  {
    eoPters.resize(_pop.size());
    _pop.shuffle(eoPters);
    // now get the best
    unsigned int ibest = 0;
    const EOT * best = eoPters[0];
    if (_pop.size() == 1)
      throw std::runtime_error("Trying eoEliteSequentialSelect with only one individual!");
    for (unsigned i=1; i<_pop.size(); i++)
      if (*eoPters[i]>*best)
        {
          ibest = i;
          best = eoPters[ibest];
        }
    // and put it upfront
    const EOT *ptmp = eoPters[0];
    eoPters[0]=best;
    eoPters[ibest] = ptmp;
    // exit after setting current
    current=0;
  }

  virtual const EOT& operator()(const eoPop<EOT>& _pop)
  {
    if (current >= _pop.size())
      setup(_pop);

    unsigned eoN = current;
    current++;
    return *eoPters[eoN] ;
  }
private:
  unsigned current;
  std::vector<const EOT*> eoPters;
};


#endif

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