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

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

#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 eoSelect<EOT>
{
 public:
  ///
  eoRandomSelect(const float& _percent = 0.4): eoSelect<EOT>(), rate(_percent) {};
  
  ///
  virtual ~eoRandomSelect() {};
  
  /// Takes a percentage of the population randomly, and transfers it to siblings
  virtual void operator() ( const eoPop<EOT>& _parents, eoPop<EOT>& _siblings ) const {
    // generates random numbers
    eoUniform<unsigned> uniform(0, _parents.size()-1);
    unsigned num_chroms = (unsigned)(rate * _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 >> rate;
  }

  /** 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 << rate;
  }

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

  //@}


 private:
  float rate;
};

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

#endif EOGSRANDOMSELECT_H