87 lines
2.7 KiB
C++
87 lines
2.7 KiB
C++
// -*- mode: c++; c-indent-level: 4; c++-member-init-indent: 8; comment-column: 35; -*-
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// eoProportionalSelect.h
|
|
// (c) GeNeura Team, 1998 - 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 eoProportionalSelect_h
|
|
#define eoProportionalSelect_h
|
|
|
|
//-----------------------------------------------------------------------------
|
|
|
|
#include <utils/eoRNG.h>
|
|
#include <utils/selectors.h>
|
|
#include <eoSelectOne.h>
|
|
#include <eoPop.h>
|
|
|
|
/** eoProportionalSelect: select an individual proportional to her stored fitness
|
|
value
|
|
|
|
Changed the algorithm to make use of a cumulative array of fitness scores,
|
|
This changes the algorithm from O(n) per call to O(log n) per call. (MK)
|
|
|
|
@ingroup Selectors
|
|
*/
|
|
template <class EOT> class eoProportionalSelect: public eoSelectOne<EOT>
|
|
{
|
|
public:
|
|
/// Sanity check
|
|
eoProportionalSelect(const eoPop<EOT>& pop = eoPop<EOT>())
|
|
{
|
|
if (minimizing_fitness<EOT>())
|
|
throw std::logic_error("eoProportionalSelect: minimizing fitness");
|
|
}
|
|
|
|
void setup(const eoPop<EOT>& _pop)
|
|
{
|
|
if (_pop.size() == 0) return;
|
|
|
|
cumulative.resize(_pop.size());
|
|
cumulative[0] = _pop[0].fitness();
|
|
|
|
for (unsigned i = 1; i < _pop.size(); ++i)
|
|
{
|
|
cumulative[i] = _pop[i].fitness() + cumulative[i-1];
|
|
}
|
|
}
|
|
|
|
/** do the selection,
|
|
*/
|
|
const EOT& operator()(const eoPop<EOT>& _pop)
|
|
{
|
|
if (cumulative.size() == 0) setup(_pop);
|
|
|
|
double fortune = rng.uniform() * cumulative.back();
|
|
typename FitVec::iterator result = std::upper_bound(cumulative.begin(), cumulative.end(), fortune);
|
|
return _pop[result - cumulative.begin()];
|
|
}
|
|
|
|
private :
|
|
|
|
typedef std::vector<typename EOT::Fitness> FitVec;
|
|
FitVec cumulative;
|
|
};
|
|
/** @example t-eoRoulette.cpp
|
|
*/
|
|
|
|
#endif
|