public void MutateChild(Genome child)
{
if (child == null)
{
throw new ArgumentNullException(nameof(child));
}
if (this.random.NextDouble() < this.ParentSimulation.Parameters.AddNodeProbability)
{
child.AddNodeMutation(this.Innovations);
}
else if (this.random.NextDouble() < this.ParentSimulation.Parameters.AddConnectionProbability)
{
child.AddConnectionMutation(this.Innovations);
}
else
{
if (this.random.NextDouble() < this.ParentSimulation.Parameters.MutateConnectionWeightsProbability)
{
child.MutateWeights(this.ParentSimulation.Parameters.WeightMutationPower);
}
if (this.random.NextDouble() < this.ParentSimulation.Parameters.MutateToggleEnabledProbability)
{
child.ToggleEnabledMutation();
}
if (this.random.NextDouble() < this.ParentSimulation.Parameters.MutateReenableProbability)
{
child.ReenableMutation();
}
}
}
// Performs reproduction of organisms in the genomes list
public void Reproduce(List <Genome> nextGeneration, List <Innovation> innovations)
{
if (nextGeneration == null)
{
throw new ArgumentNullException(nameof(nextGeneration));
}
if (this.Offspring <= 0)
{
return;
}
bool championCloned = false;
for (int i = 0; i < this.Offspring; ++i)
{
Genome child = null;
if (this.ChampionOffspring > 0)
{
child = this.GetChampion().Copy();
child.ParentSimulation = this.ParentSimulation;
if (this.ChampionOffspring > 1)
{
child.IsPopulationChampion = false;
child.Fitness = 0.0;
child.OriginalFitness = 0.0;
if (this.random.NextDouble() < this.ParentSimulation.Parameters.MutateConnectionWeightsProbability)
{
child.MutateWeights(this.ParentSimulation.Parameters.WeightMutationPower);
}
else
{
child.AddConnectionMutation(innovations);
}
}
else
{
child.IsPopulationChampion = true;
}
--this.ChampionOffspring;
}
else if (!championCloned && this.Offspring > 5)
{
child = this.GetChampion().Copy();
child.ParentSimulation = this.ParentSimulation;
child.IsPopulationChampion = true;
championCloned = true;
}
else
{
// Mutate only (without crossover)
if (this.random.NextDouble() < this.ParentSimulation.Parameters.MutateWithoutCrossover)
{
// Select random genome to mutate
child = this.genomes[this.random.Next(this.genomes.Count)].Copy();
child.ParentSimulation = this.ParentSimulation;
child.Fitness = 0.0;
child.OriginalFitness = 0.0;
child.IsPopulationChampion = false;
this.MutateChild(child);
}
// Perform crossover
else
{
// Select random parents
Genome parent1 = this.genomes[this.random.Next(this.genomes.Count)];
Genome parent2 = null;
// Find second parent INSIDE this species
if (this.random.NextDouble() > this.ParentSimulation.Parameters.InterspeciesMateRate)
{
parent2 = this.genomes[this.random.Next(this.genomes.Count)];
}
// Find second parent OUTSIDE this species - this should happen very very rarely
else
{
// TODO: possible modification - select only from better performing species
Species speciesFound = this;
int tries = 0;
while (speciesFound == this && tries++ < 5)
{
speciesFound = this.ParentSimulation.Species[this.random.Next(this.ParentSimulation.Species.Count)];
}
if (speciesFound.Genomes.Count == 0)
{
speciesFound = this;
}
parent2 = speciesFound.Genomes[this.random.Next(speciesFound.Genomes.Count)];
}
if (this.random.NextDouble() > this.ParentSimulation.Parameters.AverageCrossoverProbability)
{
child = parent1.Crossover(parent2, this.random);
}
else
{
child = parent2.CrossoverAverage(parent2, this.random);
}
// Mutate child
if (this.random.NextDouble() > this.ParentSimulation.Parameters.MateWithoutMutatingProbability || parent1 == parent2 || parent1.CompatibilityDistance(parent2) < 0.00001f)
{
this.MutateChild(child);
}
}
}
if (child != null)
{
nextGeneration.Add(child);
}
}
}