// -*- 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>

//-----------------------------------------------------------------------------
/** eoProportionalSelect: select an individual proportional to her stored fitness
    value 

*/
//-----------------------------------------------------------------------------

template <class EOT> class eoProportionalSelect: public eoSelectOne<EOT> 
{
public:
  /// Sanity check
  eoProportionalSelect(const eoPop<EOT>& pop = eoPop<EOT>()): 
    total((pop.size() == 0) ? -1.0 : sum_fitness(pop))
  {
    if (minimizing_fitness<EOT>())
      throw logic_error("eoProportionalSelect: minimizing fitness");
  }

  void setup(const eoPop<EOT>& _pop)
  {
    total = sum_fitness(_pop);
  }
    
  /** do the selection, call roulette_wheel. 
   */
  const EOT& operator()(const eoPop<EOT>& _pop) 
  {
    return roulette_wheel(_pop, total) ;
  }

private :
  typename EOT::Fitness total;
};

#endif