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

   -----------------------------------------------------------------------------
   eoTruncSelect.h 
   (c) Maarten Keijzer, Marc Schoenauer, GeNeura Team, 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
             mkeijzer@dhi.dk
 */
//-----------------------------------------------------------------------------

#ifndef _eoTruncSelect_h
#define _eoTruncSelect_h


//-----------------------------------------------------------------------------
#include <eoSelect.h>
#include <utils/eoHowMany.h>
#include <math.h>
//-----------------------------------------------------------------------------

/** eoTruncSelect selects individuals after truncating the population
 * using eoSelectOne as it's mechanism. 
 * Therefore eoSelectMany needs an eoSelectOne in its ctor
 * It will use an eoHowMnay to determine the number of guys to keep,
*/
template<class EOT>
class eoTruncSelect : public eoSelect<EOT>
{
 public:
  /** Ctor: from an eoSelect (and an eoMany to tell how many are kept for selectino */
  eoTruncSelect(eoSelectOne<EOT>& _select, eoHowMany _howMany) 
    : select(_select), howMany(_howMany) {}
  
     /**
     The implementation repeatidly selects an individual

     @param _source the source population
     @param _dest  the resulting population (size of this population is the number of times eoSelectOne is called. It empties the destination and adds the selection into it)
     */
  virtual void operator()(const eoPop<EOT>& _source, eoPop<EOT>& _dest)
  {
    unsigned target = howMany(_source.size());
    
    _dest.resize(target);
    
    select.setup(_source);
    
    for (size_t i = 0; i < _dest.size(); ++i)
      _dest[i] = select(_source);
  }
  
private :
  eoSelectOne<EOT>& select;
  eoHowMany howMany;
};

#endif
