private Gene mutateLink(NEATLinkGene mutatee) {
double perturbRandVal = perturbRand.nextDouble();
double disableRandVal = disableRand.nextDouble();
double newWeight;
NEATLinkGene mutated = mutatee;
if (perturbRandVal < this.pPerturb) {
if (this.pWeightReplaced > perturbRand.nextDouble()) {
newWeight = MathUtils.nextPlusMinusOne();
} else {
newWeight = mutatee.getWeight() + MathUtils.nextClampedDouble(-perturb, perturb);
}
// newWeight = mutatee.getWeight() + MathUtils.nextClampedDouble(-PERTURB, PERTURB);
mutated =
new NEATLinkGene(
mutatee.getInnovationNumber(),
mutatee.isEnabled(),
mutatee.getFromId(),
mutatee.getToId(),
newWeight);
}
if (disableRandVal < this.pToggle) {
if (this.featureSelection) {
mutated.setEnabled(!mutated.isEnabled());
}
}
return (mutated);
}
private int findChosenIndex(NEATLinkGene chosen, Chromosome mutatee) {
int idx = -1;
int i = 0;
Gene[] genes = mutatee.genes();
int mutateeSize = genes.length;
while (i < mutateeSize && idx == -1) {
if (genes[i] instanceof NEATLinkGene
&& ((NEATLinkGene) genes[i]).getFromId() == chosen.getFromId()
&& ((NEATLinkGene) genes[i]).getToId() == chosen.getToId()) {
idx = i;
} else {
i++;
}
}
return (idx);
}
private boolean linkIllegal(NEATNodeGene from, NEATNodeGene to, ArrayList links) {
boolean illegal = false;
int idx = 0;
NEATLinkGene linkGene;
if ((to.getType() == NEATNodeGene.INPUT)) {
illegal = true;
} else {
while (!illegal && (idx < links.size())) {
linkGene = (NEATLinkGene) links.get(idx);
// if ((linkGene.getFromId() == from.id() && linkGene.getToId() == to.id()) ||
// ((to.getDepth() <= from.getDepth()) && !this.recurrencyAllowed)) {
if ((linkGene.getFromId() == from.id() && linkGene.getToId() == to.id())) {
illegal = true;
}
idx++;
}
}
return (illegal);
}
private Gene[] findSourceNodes(int nodeId, Gene[] genes) {
Gene[] sourceNodes = null;
ArrayList links = this.candidateLinks(genes, true);
NEATLinkGene link;
ArrayList sources = new ArrayList();
int i;
for (i = 0; i < links.size(); i++) {
link = (NEATLinkGene) links.get(i);
if (nodeId == link.getToId()) {
// add from Id
sources.add(this.findNode(link.getFromId(), genes));
}
}
sourceNodes = new NEATNodeGene[sources.size()];
for (i = 0; i < sourceNodes.length; i++) {
sourceNodes[i] = (NEATNodeGene) sources.get(i);
}
return (sourceNodes);
}
private void mutateAddNode(Chromosome mutatee) {
double nodeRandVal = nodeRand.nextDouble();
ArrayList nodeLinks;
// ArrayList nodes;
NEATLinkGene chosen;
NEATNodeGene newNode;
NEATLinkGene newLower;
NEATLinkGene newUpper;
int newChromoIdx = mutatee.genes().length;
// Gene[] newChromo = new Gene[newChromoIdx + 3];
Gene[] newChromo = new Gene[newChromoIdx + 2];
System.arraycopy(mutatee.genes(), 0, newChromo, 0, newChromoIdx);
int linkIdx;
if (nodeRandVal < this.pAddNode) {
// add a node on an existing enabled connection
// find an existing connection to intercept
nodeLinks = this.candidateLinks(mutatee.genes(), true);
if (nodeLinks.size() > 0) {
// ensure there is a link to split
linkIdx = nodeRand.nextInt(nodeLinks.size());
chosen = (NEATLinkGene) nodeLinks.get(linkIdx);
// disable old link
chosen.setEnabled(false);
newNode = InnovationDatabase.database().submitNodeInnovation(chosen);
// newNode.setBias(MathUtils.nextPlusMinusOne());
newLower =
InnovationDatabase.database().submitLinkInnovation(chosen.getFromId(), newNode.id());
newUpper =
InnovationDatabase.database().submitLinkInnovation(newNode.id(), chosen.getToId());
// set weights according to Stanley et al's NEAT document
newLower.setWeight(1);
newUpper.setWeight(chosen.getWeight());
// now update the chromosome with new node and 2 new links
newChromo[this.findChosenIndex(chosen, mutatee)] = newNode;
// newChromo[newChromoIdx++] = newNode;
newChromo[newChromoIdx++] = newLower;
newChromo[newChromoIdx] = newUpper;
mutatee.updateChromosome(newChromo);
}
}
}
private Gene[] ensureLegalLinks(Gene[] genes) {
ArrayList links;
NEATLinkGene link;
NEATNodeGene from;
NEATNodeGene to;
Gene[] newGenes = null;
ArrayList tmpGenes = new ArrayList();
int i;
// only need to prune if recurrency not allowed
if (!this.recurrencyAllowed) {
// only return enabled links
links = this.candidateLinks(genes, false);
for (i = 0; i < genes.length; i++) {
if (genes[i] instanceof NEATLinkGene) {
link = (NEATLinkGene) genes[i];
from = this.findNode(link.getFromId(), genes);
to = this.findNode(link.getToId(), genes);
if (from.getDepth() > to.getDepth()) {
// not recurrent - so keep
tmpGenes.add(genes[i]);
}
} else {
tmpGenes.add(genes[i]);
}
}
newGenes = new Gene[tmpGenes.size()];
for (i = 0; i < newGenes.length; i++) {
newGenes[i] = (Gene) tmpGenes.get(i);
}
} else {
newGenes = genes;
}
return (newGenes);
}
private void mutateAddLink(Chromosome mutatee) {
double linkRandVal = linkRand.nextDouble();
NEATNodeGene from;
NEATNodeGene to;
int rIdx;
int i = 0;
ArrayList links;
ArrayList nodes;
Gene[] genes = new Gene[mutatee.size() + 1];
System.arraycopy(mutatee.genes(), 0, genes, 0, mutatee.genes().length);
Gene newLink = null;
if (linkRandVal < this.pAddLink) {
nodes = this.candidateNodes(mutatee.genes());
links = this.candidateLinks(mutatee.genes(), false);
// find a new available link
while (newLink == null && i < MAX_LINK_ATTEMPTS) {
rIdx = linkRand.nextInt(nodes.size());
from = ((NEATNodeGene) nodes.get(rIdx));
rIdx = linkRand.nextInt(nodes.size());
to = ((NEATNodeGene) nodes.get(rIdx));
// TODO Remove
if (from.getInnovationNumber() == 2 && to.getInnovationNumber() == 5) {
System.out.println("a");
}
if (!this.linkIllegal(from, to, links)) {
// set it to a random value
newLink = InnovationDatabase.database().submitLinkInnovation(from.id(), to.id());
((NEATLinkGene) newLink).setWeight(MathUtils.nextPlusMinusOne());
// add link between 2 unconnected nodes
genes[genes.length - 1] = newLink;
mutatee.updateChromosome(genes);
}
i++;
}
}
}