/// <summary>
/// Mutates the genome by creating a new connection.
/// </summary>
public void Mutate_Link()
{
//Get first node to connect. It is random.
NodeGene nodeGene_a = NodeGenes.RandomValue(Random).Take(1).ElementAt(0);
IEnumerable <NodeGene> temp_subset = NodeGenes.Values.Where(a => a.NodeGenePattern.X > nodeGene_a.NodeGenePattern.X);
if (temp_subset.Count() == 0)
{
return; //TODO handle this too
}
NodeGene nodeGene_b = temp_subset.ElementAt(Random.Next(temp_subset.Count())); //Get a random gene with a higher X value.
ConnectionGene connectionGene = Pedigree.Create_ConnectionGene(nodeGene_a, nodeGene_b, Pedigree.Mutation_WeightRandom * (Random.NextDouble() * 2 - 1),
true);
if (ConnectionGenes.ContainsKey(connectionGene.ConnectionGenePattern.InnovationNumber)) //Can only happen if it already existed in the tracker.
{
return; //TODO think of how to handle this, maybe have a retry somewhere?
}
ConnectionGenes.Add(connectionGene.ConnectionGenePattern.InnovationNumber, connectionGene);
}
/// <summary>
/// Mutates a random connection splitting it with a node.
/// </summary>
public void Mutate_Node()
{
if (NodeGenes.Count >= Pedigree.MaxNodes)
{
return; //Do nothing if we have max nodes.
}
else if (ConnectionGenes.Count == 0)
{
return; //Literally cannot make a node.
}
ConnectionGene connectionGene = ConnectionGenes.RandomValue(Random).Take(1).ElementAt(0);
if (connectionGene == null)
{
return;
}
NodeGene from = NodeGenes[connectionGene.ConnectionGenePattern.From.InnovationNumber];
NodeGene to = NodeGenes[connectionGene.ConnectionGenePattern.To.InnovationNumber];
NodeGene created = Pedigree.Create_NodeGene(connectionGene);
if (NodeGenes.ContainsKey(created.NodeGenePattern.InnovationNumber))
{
return; //TODO maybe retry here as well?
}
NodeGenes.Add(created.NodeGenePattern.InnovationNumber, created);
ConnectionGene created_connectionGene_1 = Pedigree.Create_ConnectionGene(from, created, 1, true); //Default weight of 1.
ConnectionGene created_connectionGene_2 = Pedigree.Create_ConnectionGene(created, to, connectionGene.Weight, connectionGene.Enabled);
ConnectionGenes.Remove(connectionGene.ConnectionGenePattern.InnovationNumber);
ConnectionGenes.Add(created_connectionGene_1.ConnectionGenePattern.InnovationNumber, created_connectionGene_1);
ConnectionGenes.Add(created_connectionGene_2.ConnectionGenePattern.InnovationNumber, created_connectionGene_2);
}
/// <summary>
/// Mutates a random node by giving it a random activation function other than the one it has right now.
/// </summary>
public void Mutate_ActivationFunction()
{
NodeGene nodeGene = NodeGenes.RandomValue(Random).Take(1).ElementAt(0);
nodeGene.ActivationFunction = Pedigree.GetRandomActivationFunction(nodeGene.ActivationFunction);
}