public function mutate(Population $population)
{
$newPopulation = new Population($population->size());
for ($populationIndex = 0; $populationIndex < $population->size(); $populationIndex++) {
$individual = $population->getFittestIndividual($populationIndex);
for ($geneIndex = 0; $geneIndex < $individual->getChromosomeLength(); $geneIndex++) {
if ($populationIndex >= $this->elitismCount) {
if ($this->mutationRate > Random::generate()) {
$newGene = 1;
if ($individual->getGene($geneIndex) == 1) {
$newGene = 0;
}
$individual->setGene($geneIndex, $newGene);
}
}
}
$newPopulation->setIndividual($populationIndex, $individual);
}
return $newPopulation;
}
public function mutateUniform(Population $population, Element $element)
{
$newPopulation = new Population($population->size());
for ($populationIndex = 0; $populationIndex < $population->size(); $populationIndex++) {
$individual = $population->getFittestIndividual($populationIndex);
$randomIndividual = new Individual($element);
for ($geneIndex = 0; $geneIndex < $individual->getChromosomeLength(); $geneIndex++) {
if ($populationIndex >= $this->elitismCount) {
if ($this->mutationRate > Random::generate()) {
$individual->setGene($geneIndex, $randomIndividual->getGene($geneIndex));
}
}
}
$newPopulation->setIndividual($populationIndex, $individual);
}
return $newPopulation;
}