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complete init1
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kellen authored and kellen committed Feb 16, 2020
1 parent 5b37233 commit 2933b4c
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197 changes: 114 additions & 83 deletions .idea/workspace.xml

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187 changes: 187 additions & 0 deletions ACO.py
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import random
import math
import numpy as np
import matplotlib.pyplot as plt


class ACO(object):
def __init__(self, num_city, data):
self.m = 30 # 蚂蚁数量
self.alpha = 1 # 信息素重要程度因子
self.beta = 5 # 启发函数重要因子
self.rho = 0.1 # 信息素挥发因子
self.Q = 1 # 常量系数
self.num_city = num_city # 城市规模
self.location = data # 城市坐标
self.Tau = np.ones([num_city, num_city]) # 信息素矩阵
self.Table = [[0 for _ in range(num_city)] for _ in range(self.m)] # 生成的蚁群
self.iter = 1
self.iter_max = 500
self.dis_mat = self.compute_dis_mat(num_city, self.location) # 计算城市之间的距离矩阵
self.Eta = 10. / self.dis_mat # 启发式函数
self.paths = None # 蚁群中每个个体的长度
# 存储存储每个温度下的最终路径,画出收敛图
self.iter_x = []
self.iter_y = []

# 轮盘赌选择
def rand_choose(self, p):
x = np.random.rand()
for i, t in enumerate(p):
x -= t
if x <= 0:
break
return i

# 生成蚁群
def get_ants(self, num_city):
for i in range(self.m):
start = np.random.randint(num_city - 1)
self.Table[i][0] = start
unvisit = list([x for x in range(num_city) if x != start])
current = start
j = 1
while len(unvisit) != 0:
P = []
# 通过信息素计算城市之间的转移概率
for v in unvisit:
P.append(self.Tau[current][v] ** self.alpha * self.Eta[current][v] ** self.beta)
P_sum = sum(P)
P = [x / P_sum for x in P]
# 轮盘赌选择一个一个城市
index = self.rand_choose(P)
current = unvisit[index]
self.Table[i][j] = current
unvisit.remove(current)
j += 1

# 计算不同城市之间的距离
def compute_dis_mat(self, num_city, location):
dis_mat = np.zeros((num_city, num_city))
for i in range(num_city):
for j in range(num_city):
if i == j:
dis_mat[i][j] = np.inf
continue
a = location[i]
b = location[j]
tmp = np.sqrt(sum([(x[0] - x[1]) ** 2 for x in zip(a, b)]))
dis_mat[i][j] = tmp
return dis_mat

# 计算一条路径的长度
def compute_pathlen(self, path, dis_mat):
a = path[0]
b = path[-1]
result = dis_mat[a][b]
for i in range(len(path) - 1):
a = path[i]
b = path[i + 1]
result += dis_mat[a][b]
return result

# 计算一个群体的长度
def compute_paths(self, paths):
result = []
for one in paths:
length = self.compute_pathlen(one, self.dis_mat)
result.append(length)
return result

# 更新信息素
def update_Tau(self):
delta_tau = np.zeros([self.num_city, self.num_city])
paths = self.compute_paths(self.Table)
for i in range(self.m):
for j in range(self.num_city - 1):
a = self.Table[i][j]
b = self.Table[i][j + 1]
delta_tau[a][b] = delta_tau[a][b] + self.Q / paths[i]
a = self.Table[i][0]
b = self.Table[i][-1]
delta_tau[a][b] = delta_tau[a][b] + self.Q / paths[i]
self.Tau = (1 - self.rho) * self.Tau + delta_tau

def aco(self):
best_lenth = math.inf
best_path = None
for cnt in range(self.iter_max):
# 生成新的蚁群
self.get_ants(self.num_city) # out>>self.Table
self.paths = self.compute_paths(self.Table)
# 取该蚁群的最优解
tmp_lenth = min(self.paths)
tmp_path = self.Table[self.paths.index(tmp_lenth)]
# 可视化初始的路径
if cnt == 0:
init_show = self.location[tmp_path]
init_show = np.vstack([init_show, init_show[0]])
plt.subplot(2, 2, 2)
plt.title('init best result')
plt.plot(init_show[:, 0], init_show[:, 1])
# 更新最优解
if tmp_lenth < best_lenth:
best_lenth = tmp_lenth
best_path = tmp_path
# 更新信息素
self.update_Tau()

# 保存结果
self.iter_x.append(cnt)
self.iter_y.append(best_lenth)
print(cnt)
return best_lenth, best_path

def run(self):
best_length, best_path = self.aco()
plt.subplot(2, 2, 4)
plt.title('convergence curve')
plt.plot(self.iter_x, self.iter_y)
return self.location[best_path], best_length


# 读取数据
def read_tsp(path):
lines = open(path, 'r').readlines()
assert 'NODE_COORD_SECTION\n' in lines
index = lines.index('NODE_COORD_SECTION\n')
data = lines[index + 1:-1]
tmp = []
for line in data:
line = line.strip().split(' ')
if line[0] == 'EOF':
continue
tmpline = []
for x in line:
if x == '':
continue
else:
tmpline.append(float(x))
if tmpline == []:
continue
tmp.append(tmpline)
data = tmp
return data


data = read_tsp('data/st70.tsp')

data = np.array(data)
plt.suptitle('ACO in st70.tsp')
data = data[:, 1:]
plt.subplot(2, 2, 1)
plt.title('raw data')
# 加上一行因为会回到起点
show_data = np.vstack([data, data[0]])
plt.plot(data[:, 0], data[:, 1])

aco = ACO(num_city=data.shape[0], data=data.copy())
Best_path, Best = aco.run()
print(Best)
plt.subplot(2, 2, 3)


Best_path = np.vstack([Best_path, Best_path[0]])
plt.plot(Best_path[:, 0], Best_path[:, 1])
plt.title('result')
plt.show()
2 changes: 2 additions & 0 deletions GA.py
Original file line number Diff line number Diff line change
Expand Up @@ -205,6 +205,8 @@ def run(self):
if tmp_best_score > best_score:
best_score = tmp_best_score
BEST_LIST = tmp_best_one
print(i)
print(1./best_score)
plt.subplot(2, 2, 4)
plt.title('convergence curve')
plt.plot(self.iter_x, self.iter_y)
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