geneross/src/Generation.cpp
Joscha 2c37b90ad8 Add Generation
Some more complex algorithms are not yet implemented.
2017-04-27 20:56:45 +00:00

97 lines
2.1 KiB
C++

#include "Generation.hpp"
size_t Generation::size = 500;
size_t Generation::living = Generation::size*0.25;
Fitness* Generation::fitness;
std::mt19937_64* Generation::re;
Generation::Generation()
{
this->individuals.reserve(Generation::size);
}
void Generation::updateFitness()
{
for (auto individual : this->individuals) {
if (!individual.fitnessEvaluated) {
individual.fitness = Generation::fitness->of(individual.chromosome);
individual.fitnessEvaluated = true;
}
}
}
void Generation::cull(CullType algorithm)
{
// sort by fitness
std::sort(
this->individuals.begin(),
this->individuals.end(),
[](Generation::Individual& a, Generation::Individual& b) -> bool {
return a.fitness < b.fitness;
}
);
// apply correct culling algorithm
switch (algorithm) {
case Generation::CUTOFF: this->cullCutoff(); break;
case Generation::ROULETTE: this->cullRoulette(); break;
}
}
void Generation::reproduce(float crossover)
{
// sort by fitness/available
std::sort(
this->individuals.begin(),
this->individuals.end(),
[](Generation::Individual& a, Generation::Individual& b) -> bool {
if (a.alive && b.alive) {
return a.fitness < b.fitness;
} else {
return a.alive;
}
}
);
// reproduce according to parameters
std::uniform_int_distribution<> alivedist(0, Generation::living-1);
std::uniform_real_distribution<> crossoverdist(0, 1);
auto it = this->individuals.begin() + Generation::living;
for (; it!=this->individuals.end(); ++it) {
auto father = this->individuals.begin() + alivedist(*Generation::re);
if (crossoverdist(*Generation::re) <= crossover) {
auto mother = this->individuals.begin() + alivedist(*Generation::re);
it->chromosome = Chromosome(father->chromosome, mother->chromosome);
} else {
it->chromosome = father->chromosome;
}
it->alive = true;
it->fitness = 0;
it->fitnessEvaluated = false;
it->chromosome.mutate();
}
}
void Generation::cullCutoff()
{
auto it = this->individuals.begin() + Generation::living;
for (; it!=this->individuals.end(); ++it) {
it->alive = false;
}
}
void Generation::cullRoulette()
{
// TODO: implement this
}