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# exercise1.3.cpp

    00001 #ifdef HAVE_CONFIG_H
    00002 #include <config.h>
    00003 #endif
    00004
    00005 //-----------------------------------------------------------------------------
    00006 // FirstBitGA.cpp
    00007 //-----------------------------------------------------------------------------
    00008 //*
    00009 // An instance of a VERY simple Bitstring Genetic Algorithm
    00010 //
    00011 //-----------------------------------------------------------------------------
    00012 // standard includes
    00013 #include <iostream>
    00014 #include <stdexcept>
    00015
    00016 // the general include for eo
    00017 #include <eo>
    00018
    00019 //-----------------------------------------------------------------------------
    00020 // Include the corresponding file
    00021 #include <ga.h>          // bitstring representation & operators
    00022 // define your individuals
    00023 typedef eoBit<double> Indi;     // A bitstring with fitness double
    00024
    00025 using namespace std;
    00026
    00027 //-----------------------------------------------------------------------------
    00032 double binary_value(const Indi & _indi)
    00033 {
    00034   double sum = 0;
    00035   for (unsigned i = 0; i < _indi.size(); i++)
    00036     sum += _indi[i];
    00037   return sum;
    00038 }
    00039
    00040 //-----------------------------------------------------------------------------
    00041
    00042 void main_function(int argc, char **argv)
    00043 {
    00044   const unsigned int SEED = 42; // seed for random number generator
    00045   const unsigned int VEC_SIZE = 8; // Number of bits in genotypes
    00046   const unsigned int POP_SIZE = 20; // Size of population
    00047   const unsigned int MAX_GEN = 500; // Maximum number of generation before STOP
    00048   const float CROSS_RATE = 0.8; // Crossover rate
    00049   const double P_MUT_PER_BIT = 0.01;    // probability of bit-flip mutation
    00050   const float MUT_RATE = 1.0;   // mutation rate
    00051
    00053   //  Random seed
    00055   //reproducible random seed: if you don't change SEED above,
    00056   // you'll aways get the same result, NOT a random run
    00057   rng.reseed(SEED);
    00058
    00060   // Fitness function
    00062   // Evaluation: from a plain C++ fn to an EvalFunc Object
    00063   eoEvalFuncPtr<Indi> eval(  binary_value );
    00064
    00066   // Initilisation of population
    00068
    00069   // declare the population
    00070   eoPop<Indi> pop;
    00071   // fill it!
    00072   for (unsigned int igeno=0; igeno<POP_SIZE; igeno++)
    00073     {
    00074       Indi v;           // void individual, to be filled
    00075       for (unsigned ivar=0; ivar<VEC_SIZE; ivar++)
    00076         {
    00077           bool r = rng.flip(); // new value, random in {0,1}
    00078           v.push_back(r);       // append that random value to v
    00079         }
    00080       eval(v);                  // evaluate it
    00081       pop.push_back(v);         // and put it in the population
    00082     }
    00083
    00084   // sort pop before printing it!
    00085   pop.sort();
    00086   // Print (sorted) intial population (raw printout)
    00087   cout << "Initial Population" << endl;
    00088   cout << pop;
    00089
    00091   // selection and replacement
    00093
    00094   // solution solution solution: uncomment one of the following,
    00095   //                             comment out the eoDetTournament lines
    00096
    00097   // The well-known roulette
    00098   // eoProportionalSelect<Indi> select;
    00099
    00100   // could also use stochastic binary tournament selection
    00101   //
    00102   //  const double RATE = 0.75;
    00103   //  eoStochTournamentSelect<Indi> select(RATE);     // RATE in ]0.5,1]
    00104   // The robust tournament selection
    00105   const unsigned int T_SIZE = 3; // size for tournament selection
    00106   eoDetTournamentSelect<Indi> select(T_SIZE);       // T_SIZE in [2,POP_SIZE]
    00107
    00108   // and of course the random selection
    00109   // eoRandomSelect<Indi> select;
    00110
    00111   // The simple GA evolution engine uses generational replacement
    00112   // so no replacement procedure is needed
    00113
    00115   // termination condition
    00117   // stop after MAX_GEN generations
    00118   eoGenContinue<Indi> continuator(MAX_GEN);
    00119
    00120
    00122   // The variation operators
    00124   // standard bit-flip mutation for bitstring
    00125   eoBitMutation<Indi>  mutation(P_MUT_PER_BIT);
    00126   // 1-point mutation for bitstring
    00127   eo1PtBitXover<Indi> xover;
    00128
    00130   // the algorithm
    00132   // standard Generational GA requires as parameters
    00133   // selection, evaluation, crossover and mutation, stopping criterion
    00134
    00135
    00136   eoSGA<Indi> gga(select, xover, CROSS_RATE, mutation, MUT_RATE,
    00137                    eval, continuator);
    00138
    00139   // Apply algo to pop - that's it!
    00140   gga(pop);
    00141
    00142   // Print (sorted) intial population
    00143   pop.sort();
    00144   cout << "FINAL Population\n" << pop << endl;
    00145 }
    00146
    00147 // A main that catches the exceptions
    00148
    00149 int main(int argc, char **argv)
    00150 {
    00151
    00152     try
    00153     {
    00154         main_function(argc, argv);
    00155     }
    00156     catch(exception& e)
    00157     {
    00158         cout << "Exception: " << e.what() << '\n';
    00159     }
    00160
    00161     return 1;
    00162 }