/// <summary>
/// Get a list of the genes that have not been taken before. This is useful
/// if you do not wish the same gene to appear more than once in a
/// chromosome.
/// </summary>
/// <param name="source">The pool of genes to select from.</param>
/// <param name="taken">An array of the taken genes.</param>
/// <returns>Those genes in source that are not taken.</returns>
private static IGene GetNotTaken(Chromosome source,
IList<IGene> taken)
{
int geneLength = source.Genes.Count;
for (int i = 0; i < geneLength; i++)
{
IGene trial = source.Genes[i];
bool found = false;
foreach (IGene current in taken)
{
if (current.Equals(trial))
{
found = true;
break;
}
}
if (!found)
{
taken.Add(trial);
return trial;
}
}
return null;
}
/// <summary>
/// Construct an innovation list.
/// </summary>
/// <param name="population">The population.</param>
/// <param name="links">The links.</param>
/// <param name="neurons">The neurons.</param>
public NEATInnovationList(IPopulation population, Chromosome links, Chromosome neurons)
{
this.population = population;
foreach (IGene gene in neurons.Genes)
{
NEATNeuronGene neuronGene = (NEATNeuronGene)gene;
NEATInnovation innovation = new NEATInnovation(neuronGene,
population.AssignInnovationID(), AssignNeuronID());
Innovations.Add(innovation);
}
foreach (IGene gene in links.Genes)
{
NEATLinkGene linkGene = (NEATLinkGene)gene;
NEATInnovation innovation = new NEATInnovation(linkGene
.FromNeuronID, linkGene.ToNeuronID,
NEATInnovationType.NewLink, this.population.AssignInnovationID());
Innovations.Add(innovation);
}
}
/// <summary>
/// Assuming this chromosome is the "mother" mate with the passed in
/// "father".
/// </summary>
/// <param name="mother">The mother.</param>
/// <param name="father">The father.</param>
/// <param name="offspring1">The first offspring.</param>
/// <param name="offspring2">The second offspring.</param>
public void Mate(Chromosome mother, Chromosome father,
Chromosome offspring1, Chromosome offspring2)
{
int geneLength = mother.Genes.Count;
// the chromosome must be cut at two positions, determine them
int cutpoint1 = (int)(ThreadSafeRandom.NextDouble() * (geneLength - cutLength));
int cutpoint2 = cutpoint1 + cutLength;
// handle cut section
for (int i = 0; i < geneLength; i++)
{
if (!((i < cutpoint1) || (i > cutpoint2)))
{
offspring1.Genes[i].Copy(father.Genes[i]);
offspring2.Genes[i].Copy(mother.Genes[i]);
}
}
// handle outer sections
for (int i = 0; i < geneLength; i++)
{
if ((i < cutpoint1) || (i > cutpoint2))
{
offspring1.Genes[i].Copy(mother.Genes[i]);
offspring2.Genes[i].Copy(father.Genes[i]);
}
}
}
/// <summary>
/// Perform a perturb mutation on the specified chromosome.
/// </summary>
/// <param name="chromosome">The chromosome to mutate.</param>
public void PerformMutation(Chromosome chromosome)
{
foreach (IGene gene in chromosome.Genes)
{
if (gene is DoubleGene)
{
DoubleGene doubleGene = (DoubleGene)gene;
double value = doubleGene.Value;
value += (perturbAmount - (ThreadSafeRandom.NextDouble()) * perturbAmount * 2);
doubleGene.Value = value;
}
}
}
/// <summary>
/// Construct a neural network genome.
/// </summary>
/// <param name="nga">The neural genetic algorithm.</param>
/// <param name="network">The network.</param>
public NeuralGenome(NeuralGeneticAlgorithm nga, BasicNetwork network)
: base(nga.Helper)
{
this.Organism = network;
this.networkChromosome = new Chromosome();
// create an array of "double genes"
int size = network.Structure.CalculateSize();
for (int i = 0; i < size; i++)
{
IGene gene = new DoubleGene();
this.networkChromosome.Genes.Add(gene);
}
this.Chromosomes.Add(this.networkChromosome);
Encode();
}
/// <summary>
/// Perform a shuffle mutation.
/// </summary>
/// <param name="chromosome">The chromosome to mutate.</param>
public void PerformMutation(Chromosome chromosome)
{
int length = chromosome.Genes.Count;
int iswap1 = (int)(ThreadSafeRandom.NextDouble() * length);
int iswap2 = (int)(ThreadSafeRandom.NextDouble() * length);
// can't be equal
if (iswap1 == iswap2)
{
// move to the next, but
// don't go out of bounds
if (iswap1 > 0)
{
iswap1--;
}
else
{
iswap1++;
}
}
// make sure they are in the right order
if (iswap1 > iswap2)
{
int temp = iswap1;
iswap1 = iswap2;
iswap2 = temp;
}
IGene gene1 = chromosome.Genes[iswap1];
IGene gene2 = chromosome.Genes[iswap2];
// remove the two genes
chromosome.Genes.Remove(gene1);
chromosome.Genes.Remove(gene2);
// insert them back in, reverse order
chromosome.Genes.Insert(iswap1, gene2);
chromosome.Genes.Insert(iswap2, gene1);
}
/// <summary>
/// Construct a genome, do not provide links and neurons.
/// </summary>
/// <param name="training">The owner object.</param>
/// <param name="id">The genome id.</param>
/// <param name="inputCount">The input count.</param>
/// <param name="outputCount">The output count.</param>
public NEATGenome(NEATTraining training, long id,
int inputCount, int outputCount)
: base(training)
{
GenomeID = id;
AdjustedScore = 0;
this.inputCount = inputCount;
this.outputCount = outputCount;
AmountToSpawn = 0;
speciesID = 0;
double inputRowSlice = 0.8 / (inputCount);
neuronsChromosome = new Chromosome();
linksChromosome = new Chromosome();
for (int i = 0; i < inputCount; i++)
{
neuronsChromosome.Genes.Add(new NEATNeuronGene(NEATNeuronType.Input, i,
0, 0.1 + i * inputRowSlice));
}
neuronsChromosome.Genes.Add(new NEATNeuronGene(NEATNeuronType.Bias,
inputCount, 0, 0.9));
double outputRowSlice = 1 / (double)(outputCount + 1);
for (int i = 0; i < outputCount; i++)
{
neuronsChromosome.Genes.Add(new NEATNeuronGene(NEATNeuronType.Output, i
+ inputCount + 1, 1, (i + 1) * outputRowSlice));
}
for (int i = 0; i < inputCount + 1; i++)
{
for (int j = 0; j < outputCount; j++)
{
linksChromosome.Genes.Add(new NEATLinkGene(
((NEATNeuronGene)neuronsChromosome.Genes[i]).Id,
((NEATNeuronGene)Neurons.Genes[inputCount + j + 1])
.Id, true, inputCount + outputCount + 1
+ NumGenes, RangeRandomizer.Randomize(-1,
1), false));
}
}
this.Chromosomes.Add(neuronsChromosome);
this.Chromosomes.Add(linksChromosome);
}
/// <summary>
/// Create a NEAT gnome.
/// </summary>
/// <param name="training">The owner object.</param>
/// <param name="genomeID">The genome id.</param>
/// <param name="neurons">The neurons.</param>
/// <param name="links">The links.</param>
/// <param name="inputCount">The input count.</param>
/// <param name="outputCount">The output count.</param>
public NEATGenome(NEATTraining training, long genomeID,
Chromosome neurons, Chromosome links,
int inputCount, int outputCount)
: base(training)
{
GenomeID = genomeID;
linksChromosome = links;
neuronsChromosome = neurons;
AmountToSpawn = 0;
AdjustedScore = 0;
this.inputCount = inputCount;
this.outputCount = outputCount;
this.Chromosomes.Add(neuronsChromosome);
this.Chromosomes.Add(linksChromosome);
}
/// <summary>
/// Construct a genome by copying another.
/// </summary>
/// <param name="other">The other genome.</param>
public NEATGenome(NEATGenome other)
: base(other.GA)
{
neuronsChromosome = new Chromosome();
linksChromosome = new Chromosome();
this.Chromosomes.Add(neuronsChromosome);
this.Chromosomes.Add(linksChromosome);
GenomeID = other.GenomeID;
networkDepth = other.networkDepth;
Score = other.Score;
AdjustedScore = other.AdjustedScore;
AmountToSpawn = other.AmountToSpawn;
inputCount = other.inputCount;
outputCount = other.outputCount;
speciesID = other.speciesID;
// copy neurons
foreach (IGene gene in other.Neurons.Genes)
{
NEATNeuronGene oldGene = (NEATNeuronGene)gene;
NEATNeuronGene newGene = new NEATNeuronGene(oldGene.NeuronType
, oldGene.Id, oldGene.SplitX,
oldGene.SplitY, oldGene.Recurrent, oldGene
.ActivationResponse);
this.neuronsChromosome.Genes.Add(newGene);
}
// copy links
foreach (IGene gene in other.Links.Genes)
{
NEATLinkGene oldGene = (NEATLinkGene)gene;
NEATLinkGene newGene = new NEATLinkGene(oldGene
.FromNeuronID, oldGene.ToNeuronID, oldGene
.Enabled, oldGene.InnovationId, oldGene
.Weight, oldGene.IsRecurrent);
Links.Genes.Add(newGene);
}
}
/// <summary>
/// Assuming this chromosome is the "mother" mate with the passed in
/// "father".
/// </summary>
/// <param name="mother">The mother.</param>
/// <param name="father">The father.</param>
/// <param name="offspring1">The first offspring.</param>
/// <param name="offspring2">The second offspring.</param>
public void Mate(Chromosome mother, Chromosome father,
Chromosome offspring1, Chromosome offspring2)
{
int geneLength = father.Genes.Count;
// the chromosome must be cut at two positions, determine them
int cutpoint1 = (int)(ThreadSafeRandom.NextDouble() * (geneLength - cutLength));
int cutpoint2 = cutpoint1 + cutLength;
// keep track of which genes have been taken in each of the two
// offspring, defaults to false.
IList<IGene> taken1 = new List<IGene>();
IList<IGene> taken2 = new List<IGene>();
// handle cut section
for (int i = 0; i < geneLength; i++)
{
if (!((i < cutpoint1) || (i > cutpoint2)))
{
offspring1.Genes[i].Copy(father.Genes[i]);
offspring2.Genes[i].Copy(mother.Genes[i]);
taken1.Add(offspring1.Genes[i]);
taken2.Add(offspring2.Genes[i]);
}
}
// handle outer sections
for (int i = 0; i < geneLength; i++)
{
if ((i < cutpoint1) || (i > cutpoint2))
{
offspring1.Genes[i].Copy(
SpliceNoRepeat.GetNotTaken(mother, taken1));
offspring2.Genes[i].Copy(
SpliceNoRepeat.GetNotTaken(father, taken2));
}
}
}
/// <summary>
/// Perform the crossover.
/// </summary>
/// <param name="mom">The mother.</param>
/// <param name="dad">The father.</param>
/// <returns>The child.</returns>
public NEATGenome PerformCrossover(NEATGenome mom, NEATGenome dad)
{
NEATParent best;
// first determine who is more fit, the mother or the father?
if (mom.Score == dad.Score)
{
if (mom.NumGenes == dad.NumGenes)
{
if (ThreadSafeRandom.NextDouble() > 0)
{
best = NEATParent.Mom;
}
else
{
best = NEATParent.Dad;
}
}
else
{
if (mom.NumGenes < dad.NumGenes)
{
best = NEATParent.Mom;
}
else
{
best = NEATParent.Dad;
}
}
}
else
{
if (Comparator.IsBetterThan(mom.Score, dad.Score))
{
best = NEATParent.Mom;
}
else
{
best = NEATParent.Dad;
}
}
Chromosome babyNeurons = new Chromosome();
Chromosome babyGenes = new Chromosome();
List<long> vecNeurons = new List<long>();
int curMom = 0;
int curDad = 0;
NEATLinkGene momGene;
NEATLinkGene dadGene;
NEATLinkGene selectedGene = null;
while ((curMom < mom.NumGenes) || (curDad < dad.NumGenes))
{
if (curMom < mom.NumGenes)
{
momGene = (NEATLinkGene)mom.Links.Genes[curMom];
}
else
{
momGene = null;
}
if (curDad < dad.NumGenes)
{
dadGene = (NEATLinkGene)dad.Links.Genes[curDad];
}
else
{
dadGene = null;
}
if ((momGene == null) && (dadGene != null))
{
if (best == NEATParent.Dad)
{
selectedGene = dadGene;
}
curDad++;
}
else if ((dadGene == null) && (momGene != null))
{
if (best == NEATParent.Mom)
{
selectedGene = momGene;
}
curMom++;
}
else if (momGene.InnovationId < dadGene.InnovationId)
{
if (best == NEATParent.Mom)
{
selectedGene = momGene;
}
curMom++;
}
else if (dadGene.InnovationId < momGene.InnovationId)
{
if (best == NEATParent.Dad)
{
selectedGene = dadGene;
}
curDad++;
}
else if (dadGene.InnovationId == momGene.InnovationId)
{
if (ThreadSafeRandom.NextDouble() < 0.5f)
{
selectedGene = momGene;
}
else
{
selectedGene = dadGene;
}
curMom++;
curDad++;
}
if (babyGenes.Genes.Count == 0)
{
babyGenes.Genes.Add(selectedGene);
}
else
{
if (babyGenes.Genes[babyGenes.Genes.Count - 1]
.InnovationId != selectedGene.InnovationId)
{
babyGenes.Genes.Add(selectedGene);
}
}
// Check if we already have the nodes referred to in SelectedGene.
// If not, they need to be added.
AddNeuronID(selectedGene.FromNeuronID, vecNeurons);
AddNeuronID(selectedGene.ToNeuronID, vecNeurons);
}
// now create the required nodes. First sort them into order
vecNeurons.Sort();
for (int i = 0; i < vecNeurons.Count; i++)
{
babyNeurons.Genes.Add(this.Innovations.CreateNeuronFromID(
vecNeurons[i]));
}
// finally, create the genome
NEATGenome babyGenome = new NEATGenome(this, Population
.AssignGenomeID(), babyNeurons, babyGenes, mom.InputCount,
mom.OutputCount);
return babyGenome;
}
