eoTruncatedSelectOne.h

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

#ifndef _eoTruncatedSelectOne_h
#define _eoTruncatedSelectOne_h


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

template<class EOT>
class eoTruncatedSelectOne : public eoSelectOne<EOT>
{
public:
  eoTruncatedSelectOne(eoSelectOne<EOT>& _select,
                       double  _rateFertile,
                       bool _interpret_as_rateF = true)
    : select(_select),
      howManyFertile(_rateFertile, _interpret_as_rateF),
      tmpPop(), actualPop(tmpPop)
  {}

  eoTruncatedSelectOne(eoSelectOne<EOT>& _select,
                        eoHowMany _howManyFertile)
    : select(_select), howManyFertile(_howManyFertile),
    tmpPop(), actualPop(tmpPop)
  {}


  void setup(const eoPop<EOT>& _source)
  {
    unsigned fertile = howManyFertile(_source.size());
    if (fertile == _source.size())  // noting to do, all are fertile
      {
        actualPop = _source;
      }
    else
      {
        // copy only best ferile to actualPop
        tmpPop.resize(fertile);
        std::vector<const EOT *> result;
        _source.nth_element(fertile, result);
        for (unsigned i=0; i<fertile; i++)
          tmpPop[i] = *result[i];

        // and just in case
        actualPop = tmpPop;
      }

    // AND DON'T FORGET to call the embedded select setup method on actualPop
    select.setup(actualPop);

    return;
  }

  const EOT& operator()(const eoPop<EOT>& _pop)
  {
    return select(actualPop);
  }


private :
  eoSelectOne<EOT>& select;        // selector for one guy
  eoHowMany howManyFertile;        // number of fertile guys
  eoPop<EOT> tmpPop;               // intermediate population - fertile guys
  eoPop<EOT> & actualPop;          // to avoid copies when 100% fertility
};

#endif