public static function evolvePopulation($pop)
{
$newPopulation = new population($pop->size(), false);
// Keep our best individual
if (algorithm::$elitism) {
$newPopulation->saveIndividual(0, $pop->getFittest());
}
// Crossover population
$elitismOffset = 0;
if (algorithm::$elitism) {
$elitismOffset = 1;
} else {
$elitismOffset = 0;
}
// Loop over the population size and create new individuals with
// crossover
for ($i = $elitismOffset; $i < $pop->size(); $i++) {
$indiv1 = algorithm::poolSelection($pop);
$indiv2 = algorithm::poolSelection($pop);
$newIndiv = algorithm::crossover($indiv1, $indiv2);
$newPopulation->saveIndividual($i, $newIndiv);
}
// Mutate population
for ($i = $elitismOffset; $i < $newPopulation->size(); $i++) {
algorithm::mutate($newPopulation->getIndividual($i));
}
return $newPopulation;
}
