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

//-----------------------------------------------------------------------------
// eoRandomSelect.h
// (c) GeNeura Team, 1998
/* 
    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
 */
//-----------------------------------------------------------------------------

#ifndef EORANDOMSELECT_H
#define EORANDOMSELECT_H

//-----------------------------------------------------------------------------

#include <algorithm>
#include <numeric>    // for accumulate
#include <functional>

#include <eoPopOps.h>
#include <eoUniform.h>

//-----------------------------------------------------------------------------

/** 
 * eoRandomSelect: an selection operator, which selects randomly a percentage
 of the initial population.
 */
template<class EOT> class eoRandomSelect: public eoBinPopOp<EOT>
{
 public:
  ///
  eoRandomSelect(const float& _percent = 0.4): 
    eoBinPopOp<EOT>(), repRate(_percent) {};
  
  ///
  virtual ~eoRandomSelect() {};
  
  /// Takes a percentage of the population randomly, and transfers it to siblings
  virtual void operator() ( eoPop<EOT>& _parents, eoPop<EOT>& _siblings )  {
    // generates random numbers
    eoUniform<unsigned> uniform(0, _parents.size()-1);
    unsigned num_chroms = (unsigned)(repRate * _parents.size());

    // selection of chromosomes
    do {
      _siblings.push_back(_parents[uniform()]);
    } while (_siblings.size() < num_chroms);
  }

    /// @name Methods from eoObject
  //@{
  /**
   * Read object. Reads the percentage
   * Should call base class, just in case.
   * @param _s A istream.
   */
  virtual void readFrom(istream& _s) {
	_s >> repRate;
  }

  /** Print itself: inherited from eoObject implementation. Declared virtual so that 
      it can be reimplemented anywhere. Instance from base classes are processed in
	  base classes, so you donīt have to worry about, for instance, fitness.
  @param _s the ostream in which things are written*/
  virtual void printOn( ostream& _s ) const{
	_s << repRate;
  }

  /** Inherited from eoObject 
      @see eoObject
  */
  string className() const {return "eoRandomSelect";};

  //@}


 private:
  float repRate;
};

//-----------------------------------------------------------------------------

#endif EOGSRANDOMSELECT_H