# eoPBILOrg.h

    00001 // -*- mode: c++; c-indent-level: 4; c++-member-init-indent: 8; comment-column: 35; -*-
    00002
    00003 //-----------------------------------------------------------------------------
    00004 // eoPBILOrg.h
    00005 // (c) Marc Schoenauer, Maarten Keijzer, 2001
    00006 /*
    00007     This library is free software; you can redistribute it and/or
    00008     modify it under the terms of the GNU Lesser General Public
    00009     License as published by the Free Software Foundation; either
    00010     version 2 of the License, or (at your option) any later version.
    00011
    00012     This library is distributed in the hope that it will be useful,
    00013     but WITHOUT ANY WARRANTY; without even the implied warranty of
    00014     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    00015     Lesser General Public License for more details.
    00016
    00017     You should have received a copy of the GNU Lesser General Public
    00018     License along with this library; if not, write to the Free Software
    00019     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
    00020
    00021     Contact: Marc.Schoenauer@polytechnique.fr
    00022              mkeijzer@dhi.dk
    00023  */
    00024 //-----------------------------------------------------------------------------
    00025
    00026 #ifndef _eoPBILOrg_H
    00027 #define _eoPBILOrg_H
    00028
    00029 #include <eoDistribUpdater.h>
    00030 #include <ga/eoPBILDistrib.h>
    00031
    00041 template <class EOT>
    00042 class eoPBILOrg :  public eoDistribUpdater<EOT>
    00043 {
    00044 public:
    00046   eoPBILOrg(double _LR, double _tolerance=0.0 ) :
    00047     LR(_LR), maxBound(1.0-_tolerance), minBound(_tolerance)
    00048   {}
    00049
    00050
    00052   virtual void operator()(eoDistribution<EOT> & _distrib, eoPop<EOT>& _pop)
    00053   {
    00054     const EOT & best = _pop.best_element();
    00055     eoPBILDistrib<EOT>& distrib = dynamic_cast<eoPBILDistrib<EOT>&>(_distrib);
    00056
    00057     std::vector<double> & p = distrib.value();
    00058
    00059     for (unsigned g=0; g<distrib.size(); g++)
    00060       {
    00061         //      double & r = value()[g];
    00062         p[g] *= (1-LR);
    00063         if ( best[g] )
    00064           p[g] +=  LR;
    00065         // else nothing
    00066
    00067         // stay away from 0 and 1
    00068         p[g] = std::min(maxBound, p[g]);
    00069         p[g] = std::max(minBound, p[g]);
    00070       }
    00071   }
    00072
    00073 private:
    00074   double LR;    // learning rate for best guys
    00075   double maxBound, minBound;    // proba stay away from 0 and 1 by at least tolerance
    00076 };
    00077
    00078 #endif