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eoSGA.h

//-----------------------------------------------------------------------------
// eoSGA.h
//-----------------------------------------------------------------------------
#ifndef _eoSGA_h
#define _eoSGA_h
#include <eoOp.h>
#include <eoContinue.h>
#include <eoPop.h>
#include <eoSelectOne.h>
#include <eoSelectPerc.h>
#include <eoEvalFunc.h>
#include <eoAlgo.h>
#include <apply.h>
/** The Simple Genetic Algorithm, following Holland and Goldberg
* Needs a selector (class eoSelectOne) a crossover (eoQuadratic,
*      i.e. a 2->2 operator) and a mutation with their respective rates,
*      of course an evaluation function (eoEvalFunc) and a continuator
*      (eoContinue) which gives the stopping criterion. Performs full
*      generational replacement.
*/
template <class EOT>
class eoSGA : public eoAlgo<EOT>
{
public :
// added this second ctor as I didn't like the ordering of the parameters
// in the one above. Any objection :-) MS
eoSGA(
       eoSelectOne<EOT>& _select,
       eoQuadraticOp<EOT>& _cross, float _crate,
       eoMonOp<EOT>& _mutate, float _mrate,
       eoEvalFunc<EOT>& _eval,
       eoContinue<EOT>& _cont)
     : cont(_cont),
       mutate(_mutate),
       mutationRate(_mrate),
       cross(_cross),
       crossoverRate(_crate),
       select(_select),
       eval(_eval) {}

void operator()(eoPop<EOT>& _pop)
{
    eoPop<EOT> offspring;
    do {
         select(_pop, offspring);
         unsigned i;
         for (i=0; i<_pop.size()/2; i++)
             {   // generates 2 offspring from two parents
                 if ( rng.flip(crossoverRate) )
                   {
                       cross(offspring[2*i], offspring[2*i+1]);
                   }
             }
         for (i=0; i < _pop.size(); i++)
             {
                 if (rng.flip(mutationRate) )
                     {
                         mutate(offspring[i]);
                     }
             }
         _pop.swap(offspring);
         apply<EOT>(eval, _pop);
     } while (cont(_pop));
}

private :
eoContinue<EOT>& cont;
eoMonOp<EOT>& mutate;
float mutationRate;
eoQuadraticOp<EOT>& cross;
float crossoverRate;
eoSelectPerc<EOT> select;
eoEvalFunc<EOT>& eval;

};
#endif

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Marc Schoenauer

Last modified: Sun Nov 19 19:36:21 2000