public void Epoch()
{
double totalFitness = 0;
BoxChomosome populationBest = null;
foreach (var chromosome in this.population)
{
this.CalculateFitness(chromosome);
totalFitness += chromosome.Fitness;
if (populationBest == null || populationBest.Fitness < chromosome.Fitness)
{
populationBest = chromosome;
}
}
var avarageFitness = totalFitness / this.population.Count;
Console.WriteLine("Avarage fitness {0}", avarageFitness);
Console.WriteLine("Population best fitness {0}", populationBest.Fitness);
if (this.best == null || this.best.Fitness < populationBest.Fitness)
{
this.best = populationBest;
}
if (this.best != null)
{
Console.WriteLine("Best fitness {0}", this.best.Fitness);
Console.WriteLine("------");
var decode = this.Best.Decode();
foreach (var point in decode)
{
Console.WriteLine("X{0} Y{1}", point.X, point.Y);
}
}
var oldPopulation = this.population;
oldPopulation.Sort(this.comparison);
this.population = new List<BoxChomosome>();
while (this.population.Count < Population)
{
BoxChomosome mum = this.GetChromosome(oldPopulation, totalFitness);
BoxChomosome dad = this.GetChromosome(oldPopulation, totalFitness);
BoxChomosome baby1;
BoxChomosome baby2;
mum.Crossover(dad, out baby1, out baby2);
this.population.Add(baby1);
this.population.Add(baby2);
}
Debug.Assert(this.population.Count == Population, "Invalid population length");
}
private int Compare(BoxChomosome x, BoxChomosome y)
{
return (int)(x.Fitness - y.Fitness);
}
private void CalculateFitness(BoxChomosome chromosome)
{
var decode = chromosome.Decode();
double fitness = 0;
for (int i = 0; i < this.cargo.Count; i++)
{
var box = this.cargo[i];
box.X = decode[i].X;
box.Y = decode[i].Y;
}
List<Box> nonOverlaping = new List<Box>();
foreach (var box in cargo)
{
if ( box.Width + box.X > this.width ||
box.Height + box.Y > this.length)
{
fitness = 0;
}
else
{
fitness += 10;
}
if (!this.Overlaps(box))
{
nonOverlaping.Add(box);
fitness += 10;
}
else
{
fitness = 0;
}
}
if (nonOverlaping.Count > 1)
{
var reference = nonOverlaping[0];
double distance = 0;
double coordinatesSum = 0;
for (int i = 1; i < nonOverlaping.Count; i++)
{
distance = reference.Center.Distance(nonOverlaping[i].Center);
coordinatesSum += nonOverlaping[i].X + nonOverlaping[i].Y;
}
if (distance == 0)
{
distance = 100;
}
if (coordinatesSum == 0)
{
coordinatesSum = 100;
}
fitness += 100/distance;
fitness += 100 / coordinatesSum;
}
if (fitness < 0)
{
fitness = 0;
}
chromosome.Fitness = fitness;
}