多目标黏菌优化算法的代码
时间: 2023-09-28 10:04:14 浏览: 114
【智能优化算法-粘菌算法】基于粘菌算法MOSMA求解多目标优化问题附matlab代码.zip
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多目标黏菌优化算法是一种基于生物黏菌聚集行为的优化算法,可以用于解决多目标优化问题。以下是一个简单的 Python 实现:
```python
import random
import numpy as np
# 定义目标函数
def f1(x):
return x[0]**2 + x[1]**2
def f2(x):
return (x[0]-1)**2 + x[1]**2
# 定义多目标黏菌优化算法
def MOA(num_particles, num_iterations, num_objectives, search_space, w, c1, c2):
# 初始化粒子群
particles = np.zeros((num_particles, len(search_space)))
velocities = np.zeros((num_particles, len(search_space)))
personal_best = np.zeros((num_particles, len(search_space)))
personal_best_fitness = np.zeros((num_particles, num_objectives))
global_best = np.zeros((len(search_space)))
global_best_fitness = np.zeros((num_objectives))
for i in range(num_particles):
for j in range(len(search_space)):
particles[i][j] = random.uniform(search_space[j][0], search_space[j][1])
personal_best[i] = particles[i]
personal_best_fitness[i][0] = f1(particles[i])
personal_best_fitness[i][1] = f2(particles[i])
# 迭代优化
for t in range(num_iterations):
for i in range(num_particles):
# 计算粒子间距离
distances = np.zeros((num_particles))
for j in range(num_particles):
distances[j] = np.linalg.norm(particles[i] - particles[j])
# 计算吸引力和斥力
attraction = np.zeros((len(search_space)))
repulsion = np.zeros((len(search_space)))
for j in range(num_particles):
if i == j:
continue
if personal_best_fitness[j][0] < personal_best_fitness[i][0] and personal_best_fitness[j][1] < personal_best_fitness[i][1]:
attraction += (personal_best[j] - particles[i]) / distances[j]
if personal_best_fitness[j][0] > personal_best_fitness[i][0] or personal_best_fitness[j][1] > personal_best_fitness[i][1]:
repulsion += (particles[i] - particles[j]) / distances[j]**2
# 更新速度和位置
velocities[i] = w * velocities[i] + c1 * random.uniform(0, 1) * attraction + c2 * random.uniform(0, 1) * repulsion
particles[i] += velocities[i]
# 限制位置在搜索空间内
for j in range(len(search_space)):
if particles[i][j] < search_space[j][0]:
particles[i][j] = search_space[j][0]
if particles[i][j] > search_space[j][1]:
particles[i][j] = search_space[j][1]
# 更新个体最优解和全局最优解
fitness = np.zeros((num_objectives))
fitness[0] = f1(particles[i])
fitness[1] = f2(particles[i])
if all(fitness <= personal_best_fitness[i]):
personal_best[i] = particles[i]
personal_best_fitness[i] = fitness
if all(fitness <= global_best_fitness):
global_best = particles[i]
global_best_fitness = fitness
print("Iteration {}: f1 = {}, f2 = {}".format(t, global_best_fitness[0], global_best_fitness[1]))
return global_best, global_best_fitness
# 测试算法
search_space = [(-5, 5), (-5, 5)]
w = 0.5
c1 = 0.5
c2 = 0.5
num_particles = 10
num_iterations = 100
num_objectives = 2
best_solution, best_fitness = MOA(num_particles, num_iterations, num_objectives, search_space, w, c1, c2)
print("Best solution: {}, Best fitness: {}".format(best_solution, best_fitness))
```
在上述代码中,我们首先定义了两个目标函数 `f1` 和 `f2`。接着,我们实现了多目标黏菌优化算法 `MOA`,其中包括初始化粒子群、迭代优化等步骤。最后,我们使用一个简单的测试案例来演示算法的使用。在本例中,我们使用了两个目标函数,搜索空间为二维平面上的一个矩形区域,粒子数为 10,迭代次数为 100。算法的输出为最优解和最优解的适应度值。
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