/// <summary>
/// Breeds the elites. This automatically preserves their genetic makeup to the next generation.
/// </summary>
/// <param name="rand">The random object.</param>
/// <param name="newPopulation">The new population.</param>
/// <param name="codes">The genetic codes.</param>
private void BreedElites(Random rand, List<Rat> newPopulation, String[] codes)
{
//Automatically add the top rat into the next population
Rat rat1 = new Rat(MainForm.START_POSITION, 1, 1, 1);
rat1.code = codes[0];
rat1.decoded = Decode(codes[0]);
newPopulation.Add(rat1);
//Automatically add the second top rat into the next population
Rat rat2 = new Rat(MainForm.START_POSITION, 1, 1, 1);
rat2.code = codes[1];
rat2.decoded = Decode(codes[1]);
newPopulation.Add(rat2);
int ct = 2;
//Breed the top two rats
if (numOfElites >= 4)
{
Breed(rand, newPopulation, codes[0], codes[1]);
ct += 2;
}
//Randomly select the rest of the elites in pairs
while (ct < codes.Length)
{
Breed(rand, newPopulation, codes[rand.Next(codes.Length)], codes[rand.Next(codes.Length)]);
ct += 2;
}
}
/// <summary>
/// Breed two parent rats to produce offspring.
/// </summary>
/// <param name="rand">The random object.</param>
/// <param name="newPopulation">The new population.</param>
/// <param name="parent1">The genes of parent1.</param>
/// <param name="parent2">The genes of parent2.</param>
private void Breed(Random rand, List<Rat> newPopulation, String parent1, String parent2)
{
String baby1 = string.Empty, baby2 = string.Empty;
Rat babyRat1, babyRat2;
//apply cross over to the offspring
CrossOver(rand, parent1, parent2, ref baby1, ref baby2);
//mutate the bits for the offspring
Mutate(rand, ref baby1);
Mutate(rand, ref baby2);
//create the rat objects
babyRat1 = new Rat(MainForm.START_POSITION, 1, 1, 1);
babyRat1.code = baby1;
babyRat1.decoded = Decode(baby1);
babyRat2 = new Rat(MainForm.START_POSITION, 1, 1, 1);
babyRat2.code = baby2;
babyRat2.decoded = Decode(baby2);
newPopulation.Add(babyRat1);
newPopulation.Add(babyRat2);
}
/// <summary>
/// Return the current rats in the population to be tested.
/// </summary>
/// <returns></returns>
public Rat[] CurrentRats()
{
Rat[] rats = new Rat[MainForm.current_rats_per_trial];
int ct = 0;
while (ct < MainForm.current_rats_per_trial)
{
rats[ct] = population[currentRat + ct];
++ct;
}
return rats;
}
/// <summary>
/// Gets the max score of the rats.
/// </summary>
/// <param name="rats">The rats.</param>
/// <returns></returns>
public double getMaxScore(Rat[] rats)
{
double max = 0;
foreach (Rat rat in rats)
{
if (rat.score > max)
{
max = rat.score;
}
}
return max;
}
/// <summary>
/// Return true if all rats are finished.
/// </summary>
/// <param name="rats">The rats.</param>
/// <returns></returns>
public bool finished(Rat[] rats)
{
foreach (Rat rat in rats)
{
if (!rat.finished)
{
return false;
}
}
return true;
}
/// <summary>
/// Gets the genetic codes of all elite rats.
/// </summary>
/// <param name="numbOfElites">The total number of elites.</param>
/// <returns></returns>
private String[] GetElites(int numbOfElites)
{
Rat[] elites = new Rat[numbOfElites];
String[] elite_codes = new String[numbOfElites];
int current_elite = 0, ct, current_index;
double current_elite_score;
while (current_elite < numbOfElites)
{
current_elite_score = population[0].score;
elites[current_elite] = population[0];
elite_codes[current_elite] = population[0].code;
current_index = 0;
ct = 1;
while (ct < POPULATION_SIZE - current_elite)
{
if (population[ct].score > current_elite_score)
{
current_elite_score = population[ct].score;
elites[current_elite] = population[ct];
elite_codes[current_elite] = population[ct].code;
current_index = ct;
}
++ct;
}
++current_elite;
population.RemoveAt(current_index);
}
ct = 0;
while (ct < numbOfElites)
{
population.Add(elites[ct]);
Debug.Assert(elites[ct].code.Length > 0);
++ct;
}
Debug.Assert(elite_codes.Length == numbOfElites);
return elite_codes;
}
/// <summary>
/// Creates the starting population of rats with randomly generated chromosomes.
/// </summary>
private void CreateStartingPop()
{
int ct = 0;
Random r = new Random((int)DateTime.Now.Ticks);
while (ct < POPULATION_SIZE)
{
Rat tmp = new Rat(MainForm.START_POSITION, 1, 1, 1);
tmp.code = this.GetRandomChromosome(r);
tmp.decoded = this.Decode(tmp.code);
population.Add(tmp);
++ct;
}
}