EGTRouletteSel.h

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/****************************************************************************

$Id: EGTRouletteSel.h,v 1.1.1.1 2002/10/19 08:14:51 motegi Exp $
Copyright (C) 2002 Higuchi Lab. All rights reserved.

*****************************************************************************/
#ifndef INCLUDE__ROULETTESEL_H__FILE
#define INCLUDE__ROULETTESEL_H__FILE

#include "defs.h"
#include "EGException.h"
#include "EGRandom.h"
#include "EGTSelection.h"
#include "EGTVector.h"

template<class TP>
class EGTRouletteSel : public EGTSelection<TP> {
public:
  typedef TP                      Pop;
  typedef typename Pop::Graph     Graph;
  typedef EGTVector<const Graph*> Graphs;

  EGTRouletteSel() : m_tRoulette(), m_uPopSize(0) { }
  virtual ~EGTRouletteSel() { }
  virtual void Selection(const Pop& src, Graphs& dest, UInt uCount);
  virtual void Selection(const Pop& src, Pop& dest, UInt uCount);

private:
  EGTVector<Float> m_tRoulette;
  UInt m_uPopSize;

  void SetRoulette(const Pop& src);
  UInt Select() const;
};

//============================================================================
 template<class TP>
void EGTRouletteSel<TP>::Selection(const Pop& src, Graphs& dest, UInt uCount)
{
  SetRoulette(src);
  const Graph* pg;
  for (UInt i=0; i<uCount; ++i) {
    pg = src.GetGraph(Select());
    dest.PushBack(pg);
  }
}

//============================================================================
template<class TP>
void EGTRouletteSel<TP>::Selection(const Pop& src, Pop& dest, UInt uCount)
{
  UInt uMax = src.GetNumGraphs();
  if (uMax < 1) {
    throw EGException("EGTRouletteSel::Selection(), "
                      "Can't fill the Population: no individuals",
                      __FILE__, __LINE__);
  }
  UInt uSel = (UInt)(uMax * EGRandom::NextReal());
  const Graph* pg;
  for (UInt i=0; i<uCount; ++i) {
    if (uSel == uMax) {
      uSel = 0;
    }
    pg = src.GetGraph(uSel++);
    dest.AddGraph(new Graph(*pg));
  }
}

//============================================================================
template<class TP>
void EGTRouletteSel<TP>::SetRoulette(const Pop& src) 
{
  UInt i;
  m_uPopSize = src.GetNumGraphs();
  if (m_tRoulette.Size() < m_uPopSize) {
    m_tRoulette.Resize(m_uPopSize, 0);
  }
  m_tRoulette[0] = src.GetGraph(0)->GetFitness();
  for (i=1; i<m_uPopSize; ++i) {
    m_tRoulette[i] = m_tRoulette[i-1] + src.GetGraph(i)->GetFitness();
  }
  if (m_tRoulette[m_uPopSize-1] == 0) {
    throw EGException("EGTRouletteSel::SetRoulette(), "
                      "Can't perform the selection operation: "
                      "The fitness values of all individuals are equal to 0.",
                      __FILE__, __LINE__);
  }
  for (i=0; i<m_uPopSize; ++i) {
    m_tRoulette[i] /= m_tRoulette[m_uPopSize-1];
  }
}

//============================================================================
template<class TP>
UInt EGTRouletteSel<TP>::Select() const
{
  Float fRan = EGRandom::NextReal();
  UInt i;
  for (i=0; i<m_uPopSize; ++i) {
    if (fRan <= m_tRoulette[i]) {
      break;
    }
  }
  if (i == m_uPopSize) {
    throw EGException("EGTRouletteSel::Select()", __FILE__, __LINE__);
  }
  return i;
}

#endif //INCLUDE__ROULETTESEL_H__FILE