Genome & Population Initialization

[Gerald Bianchi]

Hi!!

I am PhD student. I am using Galib to minimize a function with binary 
variables. The optimization works quite well.
However I would like to speed up the Genetic Algorithm. I would like to 
use  my own initialization for the population. I do not want to 
initialize randomly the population.

I define my own Initializer function such:

void initGen(GAGenome & c)
{
   GA1DBinaryStringGenome genome = (GA1DBinaryStringGenome &)c;

   for(int i=0; i< genome.length(); i++)
     cout << genome.gene(i,1);
}

Then I create a binary genome with the new Initializer

GA1DBinaryStringGenome genome(length, Objective);
genome.initializer(initGen);
genome.initialize();

This is my display function:

void displayGenome(GAGenome &g)
{
   GA1DBinaryStringGenome genome = (GA1DBinaryStringGenome &)g;

   for(int j=0; j<genome.length();j++)
     cout << genome.gene(j);

   cout << "   ";
}

As you can see I would like to initialize my genome to 1.
Unfortunately, when I display the genes value of my genome,
I do not get 1 but 0. All my genome is initialized with 0.

My question is: where I am wrong ?? I did not find my error.
Does anybody know something about intialization?

Many Thanks
Gerald

Here, you can find my program:
----------------------------------

#include <stdio.h>
#include <iostream.h>

#include <ga/GASimpleGA.h>	
#include <ga/GA1DBinStrGenome.h>

float Objective(GAGenome &);	
				
void initGen(GAGenome & c);
void initPop(GAPopulation &);
void displayPopulation(GASimpleGA &ga);
void displayGenome(GAGenome &g);

int main(int argc, char **argv)
{
   // Declare variables for the GA parameters and set them to some 
default values.
   int length    = 4;
   int popsize  = 10;
   int ngen     = 10;
   float pmut   = 0.1;
   float pcross = 0.3;

   for(int ii=1; ii<argc; ii++) {
     if(strcmp(argv[ii++],"seed") == 0) {
      GARandomSeed((unsigned int)atoi(argv[ii]));
     }
   }

//Creation of my genome
   GA1DBinaryStringGenome genome(length, Objective);
   genome.initializer(initGen);
   genome.initialize();

//Display my genome
   cout << "Genome display\n";
   displayGenome(genome);
   cout << "\nGenome display\n";

//Creation of my population
   GAPopulation pop(genome, length);
   pop.size(popsize);
   pop.initializer(initPop);
   pop.initialize();

//Creation of my Genetic Algorithm
   GASimpleGA ga(pop);
   //  ga.populationSize(popsize);
   ga.nGenerations(ngen);
   ga.pMutation(pmut);
   ga.pCrossover(pcross);
   ga.initialize();

//Display the individuals of my population
   displayPopulation(ga);
   cout << endl;

   while(!ga.done())
     {
       ga.step();
       displayPopulation(ga);
     }

   return 0;

}


float Objective(GAGenome& g) {
   GA1DBinaryStringGenome & genome = (GA1DBinaryStringGenome &)g;
   float y;

   y = -1*genome.gene(0) + 10*genome.gene(1) + 5*genome.gene(2) + 
6*genome.gene(3);

   return y*y;

}

// In this function, I initialize the genes to 1
// and display the new value
void initGen(GAGenome & c)
{
   GA1DBinaryStringGenome genome = (GA1DBinaryStringGenome &)c;

   for(int i=0; i< genome.length(); i++){
     cout << genome.gene(i,1);
   }
   cout << endl;
}


void initPop(GAPopulation & p)
{
   for (int i =0; i<p.size() ; i++)
     {
       cout << "*";  cout.flush();
       p.individual(i).initialize();
       displayGenome(p.individual(i));
     }
}

void displayPopulation(GASimpleGA &ga)
{
   for(int ii=0; ii<ga.population().size(); ii++)
     {
  	ga.population().individual(ii);
	displayGenome(ga.population().individual(ii));
     }
   cout << endl;
}

void displayGenome(GAGenome &g)
{
   GA1DBinaryStringGenome genome = (GA1DBinaryStringGenome &)g;

   for(int j=0; j<genome.length();j++)
     cout << genome.gene(j);

   cout << "   ";
}


Here I provide you the result:
----------------------------------


1111                  //I display the intialized genome from the
                       //initGen function
Genome display
0000                  //From the displayGenome function, I display
                       //the genome. As you can see, my initialisation
                       //did not work
Genome display        //Here I initialize my population

 From displayGenome      From initGen
0000                       *1111
0000                       *1111
0000                       *1111
0000                       *1111
0000                       *1111
0000                       *1111
0000                       *1111
0000                       *1111
0000                       *1111
0000                       *1111
0000                       *1111
0000                       *1111
0000                       *1111
0000                       *1111
0000                       *1111
0000                       *1111
0000                       *1111
0000                       *1111
0000                       *1111
0000                       *1111

Pop size = 10
//Display the population before the Genetic Algortihm is running
0000   0000   0000   0000   0000   0000   0000   0000   0000   0000

//Display the population when the Genetic Algortihm is running
0010   1000   0000   0000   0000   0000   0000   0000   0000   0000
0010   1000   1000   0000   0000   0000   0000   0000   0000   0000
1101   0001   1001   0010   1010   1010   0000   0000   0000   0000
1101   0100   1100   0001   1001   1001   1010   1010   1000   0000
0101   0110   1110   1011   1100   0001   1001   1010   1010   1000
0101   0110   1101   1110   1100   0010   1010   1010   1000   1000
0101   0110   1101   0110   1101   1100   0010   1010   1000   0000
1111   0101   0110   0110   1101   1101   0011   1100   1100   0010
0111   0111   1111   0101   0110   0110   1101   0110   1110   1100
0111   1111   1111   1111   1111   1101   1101   1101   1110   0100

The GA found:
0111
Nb crossover:
36
NB mutations:
42
Nb generation:
10


-- 
***************************************
*  Bianchi Gerald                     *
*  ETH Zurich                         *
*  Computer Vision Laboratory (BIWI)  *
*                                     *
*  Gloriastrasse 35                   *
*  CH-8092 Zurich                     *
*  Switzerland                        *
*  phone: +41 1 632 51 80             *
*  email: bianchi at vision.ee.ethz.ch   *
*  http://www.vision.ee.ethz.ch       *
***************************************