自适应遗传算法 python代码
时间: 2023-08-30 09:10:45 浏览: 166
以下是一个简单的自适应遗传算法的 Python 代码示例:
```python
import random
# 定义适应度函数
def fitness_function(solution):
return sum(solution)
# 定义自适应遗传算法
def adaptive_genetic_algorithm(population_size, chromosome_length, crossover_probability, mutation_probability, elitism_count, fitness_function):
# 初始化种群
population = []
for i in range(population_size):
chromosome = [random.randint(0, 1) for j in range(chromosome_length)]
population.append(chromosome)
# 迭代次数
num_generations = 100
# 开始迭代
for generation in range(num_generations):
# 计算每个染色体的适应度
fitness_scores = [fitness_function(chromosome) for chromosome in population]
max_fitness = max(fitness_scores)
average_fitness = sum(fitness_scores) / population_size
print("Generation:", generation, "Max fitness:", max_fitness, "Average fitness:", average_fitness)
# 按适应度排序,选择精英个体
elite_population = []
for i in range(elitism_count):
index = fitness_scores.index(max(fitness_scores))
elite_population.append(population[index])
fitness_scores.pop(index)
population.pop(index)
# 交叉操作
for i in range(population_size - elitism_count):
# 随机选择两个染色体进行交叉
chromosome1 = random.choice(population)
chromosome2 = random.choice(population)
# 随机选择交叉点
crossover_point = random.randint(1, chromosome_length - 1)
# 交叉操作
if random.random() < crossover_probability:
new_chromosome = chromosome1[:crossover_point] + chromosome2[crossover_point:]
else:
new_chromosome = chromosome1
# 变异操作
for j in range(chromosome_length):
if random.random() < mutation_probability:
new_chromosome[j] = 1 - new_chromosome[j]
population.append(new_chromosome)
# 将精英个体加入新种群
population += elite_population
# 返回最优解
fitness_scores = [fitness_function(chromosome) for chromosome in population]
index = fitness_scores.index(max(fitness_scores))
return population[index]
```
在这个示例代码中,我们使用了 Python 的列表来表示二进制染色体。适应度函数被定义为所有基因的和。在每个迭代中,我们计算每个染色体的适应度,并选择精英个体进行交叉和变异操作。最后返回最优解。
需要注意的是,这只是一个简单的示例代码,实际应用中需要根据具体问题进行修改和优化。
阅读全文