freESRandomMultiParentSelector.txx

Go to the documentation of this file.

/*=========================================================================

  Program:   F.R.E.E. - flexible registration evaluation engine
  Version:   v.1.0.0
  Date:      $Date: 2006/09/01 12:00:00 $
  Module:    $RCSfile: freESRandomMultiParentSelector.txx,v $
  Language:  C++



  Copyright (c) 2007 Ralf o Floca (Department of Medical Informatics,
  Institute for Medical Biometry and Informatics, University of Heidelberg,
  Germany). All rights reserved.
  See FREECopyright.txt or http://www.mi.med.uni-hd.de/free/copyright.htm
  for details.

     This software is distributed WITHOUT ANY WARRANTY; without even 
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR 
     PURPOSE.  See the above copyright notices for more information.

=========================================================================*/
#ifndef _freESRandomMultiParentSelector_txx
#define _freESRandomMultiParentSelector_txx

#include "freESRandomMultiParentSelector.h"

#include <time.h>

namespace FREE
{
  namespace ES
  {

    template <class TIndividual>
    RandomMultiParentSelector<TIndividual>
      ::RandomMultiParentSelector()
    {
      m_RandomGenerator = VariateGeneratorType::New();
      m_RandomGenerator->Initialize((int)clock());
      m_AllowRedraw = true;
      m_NumberOfSelections = 1;
    }

    template <class TIndividual>
    typename RandomMultiParentSelector<TIndividual>::ParentSelectionType
      RandomMultiParentSelector<TIndividual>
      ::Select(const PopulationType& population) const
    {
      if (!m_AllowRedraw && (population.size()<m_NumberOfSelections)) throwExceptionMacro("Error. No redrawing allowed, but size of population is smaller the number of draws. Population size: "<<population.size()<<"; number of draws: "<<m_NumberOfSelections);

      //create index pool to draw from
      typedef typename PopulationType::ElementIdentifier PopulationElementIdentifier;
      typedef std::vector<PopulationElementIdentifier> IdentifierListType;
      IdentifierListType indexPool;
      IdentifierListType selection;

      for (PopulationElementIdentifier index = 0; index<population.size(); indexPool.push_back(index++));

      //draw
      for (unsigned int count = 0; count<m_NumberOfSelections; count++)
      {
        VariateGeneratorType::IntegerType selectedIndex = m_RandomGenerator->GetIntegerVariate(indexPool.size()-1);
        selection.push_back(indexPool[selectedIndex]);
        if (!m_AllowRedraw)
        { //remove selected index from pool
          indexPool.erase(indexPool.begin()+selectedIndex);
        }
      }

      ParentSelectionType selectedIndividuals;
      
      for (typename IdentifierListType::const_iterator pos = selection.begin(); pos!=selection.end(); pos++)
      {
        selectedIndividuals.push_back(population.ElementAt(*pos));
      }

      return selectedIndividuals;
    }

  } // end of namespace ES
} // end of namespace FREE

#endif

---