private IGenome GetRandomGenomeBiasFitness(IEnumerable <IGenome> genomes)
{
double fitnessThreshold = RandomHelpers.GetRandomBiasingLow(1, 5);
fitnessThreshold = genomes.Max(g => g.Fitness) / fitnessThreshold;
return(genomes.OrderBy(g => g.Fitness).Where(g => g.Fitness >= fitnessThreshold).First());
}
private double GetSoftenFactor(double fitness, IEnumerable <IGenome> genomes)
{
double fitnessThreshold = RandomHelpers.GetRandomBiasingLow(1, 5);
fitnessThreshold = genomes.Max(g => g.Fitness) / fitnessThreshold;
return(fitness > fitnessThreshold ? new Random().Next(2, 4) : 1);
}
private ISpecies GetRandomSpeciesBiasFitness(IEnumerable <ISpecies> species)
{
if (!species.Any())
{
return(Population.BestSpecies);
}
double fitnessThreshold = RandomHelpers.GetRandomBiasingLow(1, 5);
fitnessThreshold = species.Max(s => s.Fitness) / fitnessThreshold;
return(species.OrderBy(s => s.Fitness).Where(s => s.Fitness >= fitnessThreshold).First());
}
public INode MutateAddNode()
{
int innovation = (int)RandomHelpers.GetRandomBiasingLow(
Genes.Min(g => g.Innovation), Genes.Max(g => g.Innovation)
);
IGene oldGene = Genes.FirstOrDefault(g => g.Innovation <= innovation);
if (oldGene == null)
{
oldGene = Genes[new Random().Next(Genes.Count)];
}
INode newNode = new Node(NodeType.Hidden);
// Disable the old connection
oldGene.IsExpressed = false;
// Add new connections
IGene newGeneIn = new Gene(
oldGene.NodeOut,
newNode,
GetNextInnovation(),
1
);
IGene newGeneOut = new Gene(
newNode,
oldGene.NodeIn,
GetNextInnovation(),
oldGene.Weight
);
Nodes.Add(newNode);
Genes.Add(newGeneIn);
Genes.Add(newGeneOut);
return(newNode);
}