void ACSAnt::offline_pheromone_update(OptimizationProblem &op, PheromoneMatrix &pheromones, double weight) {
for(unsigned int i=0;i<tour->size();i++) {
double pheromone = op.pheromone_update((*tour)[i], tour->get_length());
if(i==0) {
pheromones.add(pheromones.size()-1, (*tour)[i], weight * pheromones.get_evaporation_rate() * pheromone);
} else {
pheromones.add((*tour)[i-1], (*tour)[i], weight * pheromones.get_evaporation_rate() * pheromone);
}
}
}
double compute_average_pheromone_update(OptimizationProblem &op) {
SimpleAnt ant(op.get_max_tour_size());
PheromoneMatrix matrix(op.number_of_vertices(), 0.0, 1.0);
ant.construct_rational_solution(op, matrix, 0, 1);
std::vector<unsigned int> tour = ant.get_vertices();
double tour_length = op.eval_tour(tour);
double pheromone_sum = 0.0;
for(unsigned int i=0;i<tour.size();i++) {
pheromone_sum += op.pheromone_update(tour[i], tour_length);
}
double pheromone_avg = pheromone_sum / tour.size();
return pheromone_avg;
}
