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Diffstat (limited to 'multiple_ant_colony_system.py')
| -rw-r--r-- | multiple_ant_colony_system.py | 337 |
1 files changed, 337 insertions, 0 deletions
diff --git a/multiple_ant_colony_system.py b/multiple_ant_colony_system.py new file mode 100644 index 0000000..b292072 --- /dev/null +++ b/multiple_ant_colony_system.py @@ -0,0 +1,337 @@ +import numpy as np +import random +from vprtw_aco_figure import VrptwAcoFigure +from vrptw_base import VrptwGraph, PathMessage +from ant import Ant +from threading import Thread, Event +from queue import Queue +from concurrent.futures import ThreadPoolExecutor +import copy + + +class MultipleAntColonySystem: + def __init__(self, graph: VrptwGraph, ants_num=10, max_iter=200, alpha=1, beta=2): + super() + # graph 结点的位置、服务时间信息 + self.graph = graph + # ants_num 蚂蚁数量 + self.ants_num = ants_num + # max_iter 最大迭代次数 + self.max_iter = max_iter + # vehicle_capacity 表示每辆车的最大载重 + self.max_load = graph.vehicle_capacity + # 信息素强度 + self.Q = 1 + # alpha 信息素信息重要新 + self.alpha = alpha + # beta 启发性信息重要性 + self.beta = beta + # q0 表示直接选择概率最大的下一点的概率 + self.q0 = 0.1 + # best path + self.best_path_distance = None + self.best_path = None + self.best_vehicle_num = None + + self.whether_or_not_to_show_figure = True + + @staticmethod + def stochastic_accept(index_to_visit, transition_prob): + """ + 轮盘赌 + :param index_to_visit: a list of N index (list or tuple) + :param transition_prob: + :return: selected index + """ + # calculate N and max fitness value + N = len(index_to_visit) + + # normalize + sum_tran_prob = np.sum(transition_prob) + norm_transition_prob = transition_prob/sum_tran_prob + + # select: O(1) + while True: + # randomly select an individual with uniform probability + ind = int(N * random.random()) + if random.random() <= norm_transition_prob[ind]: + return index_to_visit[ind] + + @staticmethod + def new_active_ant(ant: Ant, vehicle_num: int, local_search: bool, IN: np.numarray, q0: float, stop_event: Event): + # print('[new_active_ant]: start, start_index %d' % ant.travel_path[0]) + + # 在new_active_ant中，最多可以使用vehicle_num个车，即最多可以包含vehicle_num+1个depot结点，由于出发结点用掉了一个，所以只剩下vehicle个depot + unused_depot_count = vehicle_num + + # 如果还有未访问的结点，并且还可以回到depot中 + while not ant.index_to_visit_empty() and unused_depot_count > 0: + if stop_event.is_set(): + # print('[new_active_ant]: receive stop event') + return + + # 计算所有满足载重等限制的下一个结点 + next_index_meet_constrains = ant.cal_next_index_meet_constrains() + + # 如果没有满足限制的下一个结点，则回到depot中 + if len(next_index_meet_constrains) == 0: + ant.move_to_next_index(0) + unused_depot_count -= 1 + continue + + # 开始计算满足限制的下一个结点，选择各个结点的概率 + index_num = len(next_index_meet_constrains) + ready_time = np.zeros(index_num) + due_time = np.zeros(index_num) + + for i in range(index_num): + ready_time[i] = ant.graph.nodes[next_index_meet_constrains[i]].ready_time + due_time[i] = ant.graph.nodes[next_index_meet_constrains[i]].due_time + + delivery_time = np.array([max(i, j) for i, j in zip(ant.vehicle_travel_time + ant.graph.node_dist_mat[ant.current_index][next_index_meet_constrains], ready_time)]) + + delta_time = delivery_time - ant.vehicle_travel_time + distance = delta_time * (due_time - ant.vehicle_travel_time) + + distance = np.array([max(1.0, j) for j in distance-IN[next_index_meet_constrains]]) + closeness = 1/distance + + # 按照概率直接选择closeness最大的结点 + if np.random.rand() < q0: + max_prob_index = np.argmax(closeness) + next_index = next_index_meet_constrains[max_prob_index] + else: + # 使用轮盘赌算法 + next_index = MultipleAntColonySystem.stochastic_accept(next_index_meet_constrains, closeness) + + # 更新信息素矩阵 + ant.graph.local_update_pheromone(ant.current_index, next_index) + ant.move_to_next_index(next_index) + + # 如果走完所有的点了，需要回到depot + if ant.index_to_visit_empty(): + ant.move_to_next_index(0) + + # 对未访问的点进行插入，保证path是可行的 + ant.insertion_procedure(stop_event) + + # ant.index_to_visit_empty()==True就是feasible的意思 + if local_search is True and ant.index_to_visit_empty(): + ant.local_search_procedure(stop_event) + + @staticmethod + def acs_time(new_graph: VrptwGraph, vehicle_num, ants_num, q0, global_path_queue: Queue, path_found_queue: Queue, stop_event: Event): + # 最多可以使用vehicle_num辆车，即在path中最多包含vehicle_num+1个depot中，找到路程最短的路径， + # vehicle_num设置为与当前的best_path一致 + print('[acs_time]: start, vehicle_num %d' % vehicle_num) + # 初始化信息素矩阵 + global_best_path = None + global_best_distance = None + ants_pool = ThreadPoolExecutor(ants_num) + ants_thread = [] + ants = [] + while True: + + if stop_event.is_set(): + print('[acs_time]: receive stop event') + return + + for k in range(ants_num): + ant = Ant(new_graph, 0) + thread = ants_pool.submit(MultipleAntColonySystem.new_active_ant, ant, vehicle_num, True, np.zeros(new_graph.node_num), q0, stop_event) + + ants_thread.append(thread) + ants.append(ant) + + # 这里可以使用result方法，等待线程跑完 + for thread in ants_thread: + thread.result() + + # 判断蚂蚁找出来的路径是否是feasible的，并且比全局的路径要好 + for ant in ants: + + if stop_event.is_set(): + print('[acs_time]: receive stop event') + return + + # 如果比全局的路径要好，则要将该路径发送到macs中 + if not global_path_queue.empty(): + info = global_path_queue.get() + while not global_path_queue.empty(): + info = global_path_queue.get() + print('[acs_time]: receive global path info') + global_best_path, global_best_distance = info.get_path_info() + + if ant.index_to_visit_empty() and ant.total_travel_distance < global_best_distance: + print('[acs_time]: found a improved feasible path, send path info to macs') + path_found_queue.put(PathMessage(ant.travel_path, ant.total_travel_distance)) + + # 在这里执行信息素的全局更新 + new_graph.global_update_pheromone(global_best_path, global_best_distance) + + @staticmethod + def acs_vehicle(new_graph: VrptwGraph, vehicle_num: int, ants_num: int, q0: float, global_path_queue: Queue, path_found_queue: Queue, stop_event: Event): + # 最多可以使用vehicle_num辆车，即在path中最多包含vehicle_num+1个depot中，找到路程最短的路径， + # vehicle_num设置为比当前的best_path少一个 + print('[acs_vehicle]: start, vehicle_num %d' % vehicle_num) + global_best_path = None + global_best_distance = None + + # 使用邻近点算法初始化path 和distance + current_path, current_path_distance = new_graph.nearest_neighbor_heuristic() + + # 找出当前path中未访问的结点 + current_index_to_visit = list(range(new_graph.node_num)) + for ind in set(current_path): + current_index_to_visit.remove(ind) + + ants_pool = ThreadPoolExecutor(ants_num) + ants_thread = [] + ants = [] + IN = np.zeros(new_graph.node_num) + while True: + + if stop_event.is_set(): + print('[acs_vehicle]: receive stop event') + return + + for k in range(ants_num): + ant = Ant(new_graph, 0) + thread = ants_pool.submit(MultipleAntColonySystem.new_active_ant, ant, vehicle_num, True, IN, q0, stop_event) + + ants_thread.append(thread) + ants.append(ant) + + # 这里可以使用result方法，等待线程跑完 + for thread in ants_thread: + thread.result() + + for ant in ants: + + if stop_event.is_set(): + print('[acs_vehicle]: receive stop event') + return + + index_to_visit = copy.deepcopy(ant.index_to_visit) + IN[index_to_visit] = IN[index_to_visit]+1 + + # 判断蚂蚁找出来的路径是否比current_path，能使用vehicle_num辆车访问到更多的结点 + if len(index_to_visit) < len(current_index_to_visit): + current_path = copy.deepcopy(ant.travel_path) + current_index_to_visit = index_to_visit + current_path_distance = ant.total_travel_distance + # 并且将IN设置为0 + IN = np.zeros(new_graph.node_num) + + # 如果这一条路径是feasible的话，就要发到macs_vrptw中 + if ant.index_to_visit_empty(): + print('[acs_vehicle]: found a feasible path, send path info to macs') + path_found_queue.put(PathMessage(ant.travel_path, ant.total_travel_distance)) + + # 更新new_graph中的信息素，global + new_graph.global_update_pheromone(current_path, current_path_distance) + + if not global_path_queue.empty(): + info = global_path_queue.get() + while not global_path_queue.empty(): + info = global_path_queue.get() + print('[acs_vehicle]: receive global path info') + global_best_path, global_best_distance = info.get_path_info() + + new_graph.global_update_pheromone(global_best_path, global_best_distance) + + def run_multiple_ant_colony_system(self): + # _multiple_ant_colony_system，使用主线程来绘图 + path_queue_for_figure = Queue() + multiple_ant_colony_system_thread = Thread(target=self._multiple_ant_colony_system, args=(path_queue_for_figure,)) + multiple_ant_colony_system_thread.start() + + # 是否要展示figure + if self.whether_or_not_to_show_figure: + figure = VrptwAcoFigure(self.graph, path_queue_for_figure) + figure.run() + multiple_ant_colony_system_thread.join() + + # 传入None作为结束标志 + if self.whether_or_not_to_show_figure: + path_queue_for_figure.put(PathMessage(None, None)) + + def _multiple_ant_colony_system(self, path_queue_for_figure: Queue): + # 在这里需要两个队列，time_what_to_do、vehicle_what_to_do， 用来告诉acs_time、acs_vehicle这两个线程，当前的best path是什么，或者让他们停止计算 + global_path_to_acs_time = Queue() + global_path_to_acs_vehicle = Queue() + + # 另外的一个队列， path_found_queue就是接收acs_time 和acs_vehicle计算出来的比best path还要好的feasible path + path_found_queue = Queue() + + # 使用近邻点算法初始化 + self.best_path, self.best_path_distance = self.graph.nearest_neighbor_heuristic() + self.best_vehicle_num = self.best_path.count(0) - 1 + + while True: + # 当前best path的信息 + global_path_to_acs_vehicle.put(PathMessage(self.best_path, self.best_path_distance)) + global_path_to_acs_time.put(PathMessage(self.best_path, self.best_path_distance)) + + # acs_vehicle + stop_event = Event() + graph_for_acs_vehicle = self.graph.copy(self.graph.init_pheromone_val) + acs_vehicle_thread = Thread(target=MultipleAntColonySystem.acs_vehicle, + args=(graph_for_acs_vehicle, self.best_vehicle_num-1, self.ants_num, self.q0, + global_path_to_acs_vehicle, path_found_queue, stop_event)) + + # acs_time + graph_for_acs_time = self.graph.copy(self.graph.init_pheromone_val) + acs_time_thread = Thread(target=MultipleAntColonySystem.acs_time, + args=(graph_for_acs_time, self.best_vehicle_num, self.ants_num, self.q0, + global_path_to_acs_time, path_found_queue, stop_event)) + + # 启动acs_vehicle_thread和acs_time_thread，当他们找到feasible、且是比best path好的路径时，就会发送到macs中来 + print('[macs]: start acs_vehicle and acs_time') + acs_vehicle_thread.start() + acs_time_thread.start() + + best_vehicle_num = self.best_vehicle_num + + while acs_vehicle_thread.is_alive() and acs_time_thread.is_alive(): + + if path_found_queue.empty(): + continue + + path_info = path_found_queue.get() + print('[macs]: receive found path info') + found_path, found_path_distance = path_info.get_path_info() + + # 如果找到的路径（feasible）的距离更短，则更新当前的最佳path的信息 + if found_path_distance < self.best_path_distance: + print('-' * 50) + print('[macs]: distance of found path (%f) better than best path\'s (%f)' % (found_path_distance, self.best_path_distance)) + print('-' * 50) + self.best_path = found_path + self.best_vehicle_num = found_path.count(0) - 1 + self.best_path_distance = found_path_distance + + # 如果需要绘制图形，则要找到的best path发送给绘图程序 + if self.whether_or_not_to_show_figure: + path_queue_for_figure.put(PathMessage(self.best_path, self.best_path_distance)) + + # 通知acs_vehicle和acs_time两个线程，当前找到的best_path和best_path_distance + global_path_to_acs_vehicle.put(PathMessage(self.best_path, self.best_path_distance)) + global_path_to_acs_time.put(PathMessage(self.best_path, self.best_path_distance)) + + # 如果，这两个线程找到的路径用的车辆更少了，就停止这两个线程，开始下一轮迭代 + # 向acs_time和acs_vehicle中发送停止信息 + if found_path.count(0)-1 < best_vehicle_num: + print('-' * 50) + print('[macs]: vehicle num of found path (%d) better than best path\'s (%d)' % (found_path.count(0)-1, best_vehicle_num)) + print('-' * 50) + self.best_path = found_path + self.best_vehicle_num = found_path.count(0)-1 + self.best_path_distance = found_path_distance + + if self.whether_or_not_to_show_figure: + path_queue_for_figure.put(PathMessage(self.best_path, self.best_path_distance)) + + # 停止acs_time 和 acs_vehicle 两个线程 + print('[macs]: send stop info to acs_time and acs_vehicle') + stop_event.set() |