遗传算法python代码框架
时间: 2023-12-13 11:05:13 浏览: 81
遗传算法python代码
遗传算法的Python代码框架如下所示:
```python
import random
# 初始化种群
def init_population(population_size, chromosome_length):
population = []
for i in range(population_size):
chromosome = [random.randint(0, 1) for j in range(chromosome_length)]
population.append(chromosome)
return population
# 计算适应度
def fitness(chromosome):
x = decode(chromosome)
return x ** 2
# 解码染色体
def decode(chromosome):
x = 0
for i in range(len(chromosome)):
x += chromosome[i] * (2 ** i)
return x
# 选择操作
def selection(population, fitness_values):
pass
# 交叉操作
def crossover(parent1, parent2):
pass
# 变异操作
def mutation(chromosome):
pass
# 遗传算法主程序
def genetic_algorithm(population_size, chromosome_length, max_generation):
population = init_population(population_size, chromosome_length)
for i in range(max_generation):
fitness_values = [fitness(chromosome) for chromosome in population]
parents = selection(population, fitness_values)
offspring_population = []
for j in range(population_size // 2):
parent1, parent2 = parents[j], parents[j + 1]
offspring1, offspring2 = crossover(parent1, parent2)
offspring1 = mutation(offspring1)
offspring2 = mutation(offspring2)
offspring_population.append(offspring1)
offspring_population.append(offspring2)
population = offspring_population
best_chromosome = max(population, key=fitness)
return decode(best_chromosome)
# 调用遗传算法主程序
result = genetic_algorithm(population_size=100, chromosome_length=5, max_generation=100)
print(result)
```
其中,`init_population`函数用于初始化种群,`fitness`函数用于计算适应度,`decode`函数用于解码染色体,`selection`函数用于选择操作,`crossover`函数用于交叉操作,`mutation`函数用于变异操作,`genetic_algorithm`函数是遗传算法的主程序。在主程序中,首先初始化种群,然后进行若干代的进化,每一代都进行选择、交叉和变异操作,最后返回适应度最高的染色体对应的解码结果。
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