public void NextGeneration(Species species, int numChildren)
{
if (numChildren == 0)
{
return; //hacky....
}
//replace old list with new one
var children = new List <Genome>();
var parents = new List <Genome>();
int parentCount = (int)(species.Genomes.Count * Config.survivalCutoff);
//ensure at least one parent
parentCount = Math.Max(parentCount, 1);
//only add a proportion of the population to parent pool based on survival cutoff
for (int i = 0; i < parentCount; i++)
{
parents.Add(species.Genomes[i]);
}
int asexualCount = (int)(numChildren * Config.rateAsexual);
if (parentCount == 1)
{
asexualCount = numChildren;
}
//pick random parents and cross them to get child
for (int i = 0; i < (numChildren - asexualCount); i++)
{
//don't cross the same parents
var parent1 = parents[Config.globalRandom.Next(0, parents.Count)];
var parent2 = parents[Config.globalRandom.Next(0, parents.Count)];
var parentFittest = parent1.Fitness >= parent2.Fitness ? parent1 : parent2;
//var parentWeaker = parent1.Fitness < parent2.Fitness ? parent1 : parent2;
//create child topology from fitter parent
var child = parentFittest.Clone();
//randomly crossover any shared connections
child.CrossOver(parent1, parent2);
children.Add(child);
}
//asexual reproduction
for (int i = 0; i < asexualCount; i++)
{
//add asexual in order of parents
var parent1 = parents[Config.globalRandom.Next(0, parents.Count)];
children.Add(parent1.Clone());
}
//mutate all the children genomes
foreach (var child in children)
{
//mutate individual connection weights
child.MutateConnectionWeights();
//mutate add new connection
var r1 = Config.globalRandom.NextDouble();
if (r1 < Config.rateAddConnection)
{
child.MutateAddConnection();
}
var r2 = Config.globalRandom.NextDouble();
if (r2 < Config.rateAddNode)
{
child.MutateAddNode(this);
}
//if (r2 < 0.2)
//{
// child.MutateNodeType();
//}
//if (r2 < 0.02)
//{
// child.MutateRemoveNode();
//}
}
//elitism
if (species.Genomes.Count > 5)
{
children[Config.globalRandom.Next(0, children.Count)] = parents[0].Clone();
}
species.Genomes = children;
Genomes.AddRange(children);
}