private double getCrossoverRate(IPopulation parents) {
int population_size = parents.getGenotypes().size();
if (population_size <= AVG_SIZE) return properties.getCrossoverRate();
if (population_size >= MAX_SIZE) return 0;
return properties.getCrossoverRate() * (MAX_SIZE - population_size) / MAX_SIZE;
}
@Override
public IPopulation crossover(IPopulation parents) {
logger.debug("start");
Population childs = new Population();
double crossoverRate = getCrossoverRate(parents);
if (crossoverRate <= 0) return childs;
Iterator<IGenotype> iter = parents.getGenotypes().iterator();
while (iter.hasNext()) {
Genotype parent1 = (Genotype) iter.next();
if (!iter.hasNext()) continue;
Genotype parent2 = (Genotype) iter.next();
if (random.nextDouble() < crossoverRate) childs.addGenotype(helper.create(parent1, parent2));
}
logger.debug("end");
return childs;
}