// Filters out invalid and to old individuals. Filtering is done in place.
private FilterResult<G, C> filter(final Population<G, C> population, final long generation) {
int killCount = 0;
int invalidCount = 0;
for (int i = 0, n = population.size(); i < n; ++i) {
final Phenotype<G, C> individual = population.get(i);
if (!_validator.test(individual)) {
population.set(i, newPhenotype(generation));
++invalidCount;
} else if (individual.getAge(generation) > _maximalPhenotypeAge) {
population.set(i, newPhenotype(generation));
++killCount;
}
}
return new FilterResult<>(population, killCount, invalidCount);
}
// Create a new and valid phenotype
private Phenotype<G, C> newPhenotype(final long generation) {
int count = 0;
Phenotype<G, C> phenotype;
do {
phenotype =
Phenotype.of(
_genotypeFactory.newInstance(), generation, _fitnessFunction, _fitnessScaler);
} while (++count < _individualCreationRetries && !_validator.test(phenotype));
return phenotype;
}
private EvolutionStart<G, C> evolutionStart(
final Iterable<Genotype<G>> genotypes, final long generation) {
final Stream<Phenotype<G, C>> stream =
Stream.concat(
StreamSupport.stream(genotypes.spliterator(), false)
.map(gt -> Phenotype.of(gt, generation, _fitnessFunction, _fitnessScaler)),
Stream.generate(() -> newPhenotype(generation)));
final Population<G, C> population = stream.limit(getPopulationSize()).collect(toPopulation());
return EvolutionStart.of(population, generation);
}
@Override
void accept(final Phenotype<?, N> pt, final long generation) {
super.accept(pt, generation);
_fitness.accept(pt.getFitness().doubleValue());
}
void accept(final Phenotype<?, C> pt, final long generation) {
_age.accept(pt.getAge(generation));
}
private static Phenotype<DoubleGene, Double> phenotype(final double value) {
return Phenotype.of(
Genotype.of(DoubleChromosome.of(DoubleGene.of(value, 0.0, 1000.0))),
1,
a -> a.getGene().getAllele());
}