exercise2.3.cpp

//-----------------------------------------------------------------------------
// FirstBitEA.cpp
//-----------------------------------------------------------------------------
//*
// Still an instance of a VERY simple Bitstring Genetic Algorithm
// (see FirstBitGA.cpp) but now with  Breeder - and Combined Ops
//
//-----------------------------------------------------------------------------
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

// standard includes
#include <stdexcept>  // runtime_error
#include <iostream>   // cout

// the general include for eo
#include <eo>

// REPRESENTATION
//-----------------------------------------------------------------------------
// Include the corresponding file
#include <ga.h>          // bitstring representation & operators
// define your individuals
typedef eoBit<double> Indi;     // A bitstring with fitness double

// EVAL
//-----------------------------------------------------------------------------
// a simple fitness function that computes the number of ones of a bitstring
// Now in a separate file, and declared as binary_value(const vector<bool> &)

#include "binary_value.h"

// GENERAL
//-----------------------------------------------------------------------------

using namespace std;

void main_function(int argc, char **argv)
{
// PARAMETRES
  const unsigned int SEED = 42; // seed for random number generator
  const unsigned int T_SIZE = 3; // size for tournament selection
  const unsigned int VEC_SIZE = 20; // Number of bits in genotypes
  const unsigned int POP_SIZE = 20; // Size of population

  const unsigned int MAX_GEN = 500; // Maximum number of generation before STOP
  const unsigned int MIN_GEN = 10;  // Minimum number of generation before ...
  const unsigned int STEADY_GEN = 50; // stop after STEADY_GEN gen. without improvelent

  const double P_CROSS = 0.8;   // Crossover probability
  const double P_MUT = 1.0;     // mutation probability

  const double P_MUT_PER_BIT = 0.01;    // internal probability for bit-flip mutation
  // some parameters for chosing among different operators
  const double onePointRate = 0.5;     // rate for 1-pt Xover
  const double twoPointsRate = 0.5;     // rate for 2-pt Xover
  const double URate = 0.5;            // rate for Uniform Xover
  const double bitFlipRate = 0.5;      // rate for bit-flip mutation
  const double oneBitRate = 0.5;       // rate for one-bit mutation

// GENERAL
  //  Random seed
  //reproducible random seed: if you don't change SEED above,
  // you'll aways get the same result, NOT a random run
  rng.reseed(SEED);

// EVAL
  // Fitness function
  // Evaluation: from a plain C++ fn to an EvalFunc Object
  // you need to give the full description of the function
  eoEvalFuncPtr<Indi, double, const vector<bool>& > eval(  binary_value );

// INIT
  // Initilisation of population

  // based on boolean_generator class (see utils/rnd_generator.h)
  eoUniformGenerator<bool> uGen;
  eoInitFixedLength<Indi> random(VEC_SIZE, uGen);
  // Initialization of the population
  eoPop<Indi> pop(POP_SIZE, random);

  // and evaluate it in one loop
  apply<Indi>(eval, pop);       // STL syntax

// OUTPUT
  // sort pop before printing it!
  pop.sort();
  // Print (sorted) intial population (raw printout)
  cout << "Initial Population" << endl;
  cout << pop;

// ENGINE
  // selection and replacement
// SELECT
  // The robust tournament selection
  eoDetTournamentSelect<Indi> selectOne(T_SIZE);       // T_SIZE in [2,POP_SIZE]
  // solution solution solution solution solution solution solution
  // modify the nb offspring / rate in the constructor. 2 ways:
  // second arg treated as integer
  eoSelectMany<Indi> select(selectOne,2, eo_is_an_integer);
  // second arg treated as a rate (default behavior)
  //  eoSelectMany<Indi> select(selectOne,0.1);

// REPLACE
  // solution solution solution solution solution solution solution
  // eoCommaReplacement keeps the best among offspring
  // eoPlusReplacement keeps the best among parents + offspring
  //  eoCommaReplacement<Indi> replace;
  eoPlusReplacement<Indi> replace;

// OPERATORS
  // The variation operators
// CROSSOVER
  // 1-point crossover for bitstring
  eo1PtBitXover<Indi> xover1;
  // uniform crossover for bitstring
  eoUBitXover<Indi> xoverU;
  // 2-pots xover
  eoNPtsBitXover<Indi> xover2(2);
  // Combine them with relative rates
  eoPropCombinedQuadOp<Indi> xover(xover1, onePointRate);
  xover.add(xoverU, URate);
  xover.add(xover2, twoPointsRate, true);

// MUTATION
  // standard bit-flip mutation for bitstring
  eoBitMutation<Indi>  mutationBitFlip(P_MUT_PER_BIT);
  // mutate exactly 1 bit per individual
  eoDetBitFlip<Indi> mutationOneBit;
  // Combine them with relative rates
  eoPropCombinedMonOp<Indi> mutation(mutationBitFlip, bitFlipRate);
  mutation.add(mutationOneBit, oneBitRate, true);

  // The operators are  encapsulated into an eoTRansform object
  eoSGATransform<Indi> transform(xover, P_CROSS, mutation, P_MUT);

// STOP
// CHECKPOINT
  // termination conditions: use more than one
  // stop after MAX_GEN generations
  eoGenContinue<Indi> genCont(MAX_GEN);
  // do MIN_GEN gen., then stop after STEADY_GEN gen. without improvement
  eoSteadyFitContinue<Indi> steadyCont(MIN_GEN, STEADY_GEN);
  // stop when fitness reaches a target (here VEC_SIZE)
  eoFitContinue<Indi> fitCont(VEC_SIZE);
  // do stop when one of the above says so
  eoCombinedContinue<Indi> continuator(genCont);
  continuator.add(steadyCont);
  continuator.add(fitCont);

// GENERATION
  // the algorithm

  // Easy EA requires
  // selection, transformation, eval, replacement, and stopping criterion
  eoEasyEA<Indi> gga(continuator, eval, select, transform, replace);

  // Apply algo to pop - that's it!
  gga(pop);

// OUTPUT
  // Print (sorted) intial population
  pop.sort();
  cout << "FINAL Population\n" << pop << endl;
// GENERAL
}

// A main that catches the exceptions

int main(int argc, char **argv)
{
    try
    {
        main_function(argc, argv);
    }
    catch(exception& e)
    {
        cout << "Exception: " << e.what() << '\n';
    }

    return 1;
}

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