private StringBuilder combine(ga_struct chromo1, ga_struct chromo2)
{
int tsize = GA_TARGET.Length, spos;
spos = rand() % tsize;
return(new StringBuilder(chromo1.str.ToString().Substring(0, spos) + chromo2.str.ToString().Substring(spos, tsize - spos)));
}
private void mutate(ga_struct member)
{
int tsize = GA_TARGET.Length;
int ipos = rand() % tsize;
int delta = (rand() % 90) + 32;
member.str[ipos] = (char)((member.str[ipos] + delta) % 122);
}
/*private ga_struct select(GAVector population, int tournamentSize, double p)
* {
* // Select members for the tournament at random from the population
* GAVector tournamentMembers = new GAVector();
* for (int i = 0; i < tournamentSize; ++i)
* {
* int index = rand() % GA_POPSIZE;
* tournamentMembers.Add(population[index]);
* }
*
* // Now select from the tournament members using probability p
* //double powerBase = (1 / (1-p));
* //int maxIndex = (int)Math.Pow(powerBase, tournamentSize);
* //int randomIndex = (rand() % maxIndex) + 1;
* //ga_struct selected = null;
* //for (int n=tournamentSize-1; n>=0; --n)
* //{
* // if (randomIndex >= Math.Pow(powerBase, n))
* // {
* // selected = tournamentMembers[n];
* // break;
* // }
* //}
*
* sort_by_fitness(tournamentMembers);
*
* ga_struct selected = null;
* for (int i=0; i<tournamentSize; ++i)
* {
* if (_rand.NextDouble() < p)
* {
* selected = tournamentMembers[i];
* break;
* }
* }
* selected = selected ?? tournamentMembers[0];
*
* //Debug.Assert(selected != null);
*
* return selected;
* }*/
private ga_struct select(GAVector population, int tournamentSize, double p)
{
ga_struct selected = null;
int maxIncrement = GA_POPSIZE / tournamentSize;
int index = rand() % maxIncrement;
for (int i = 0; i < tournamentSize; ++i)
{
if (_rand.NextDouble() < p)
{
selected = population[index];
break;
}
index += rand() % maxIncrement;
}
selected = selected ?? population[0];
//Debug.Assert(selected != null);
return(selected);
}
private void init_population(GAVector population, GAVector buffer)
{
int tsize = GA_TARGET.Length;
for (int i = 0; i < GA_POPSIZE; ++i)
{
ga_struct citizen = new ga_struct();
citizen.fitness = 0;
citizen.str.Clear();
for (int j = 0; j < tsize; ++j)
{
int charValue = (rand() % 90) + 32;
citizen.str.Append((char)charValue);
}
population.Add(citizen);
}
buffer.resize(GA_POPSIZE);
//var temp = new ga_struct[GA_POPSIZE];
//buffer = temp.ToList<ga_struct>();
}