写一段退火算法的Python代码
时间: 2023-02-28 09:29:26 浏览: 66
下面是一段简单的退火算法的Python代码:
```
import random
import math
def simulated_annealing(problem, Tmax, Tmin, alpha):
current_state = problem.initial_state()
current_cost = problem.cost(current_state)
T = Tmax
while T > Tmin:
i = 1
while i <= 100:
new_state = problem.random_neighbor(current_state)
new_cost = problem.cost(new_state)
delta_cost = new_cost - current_cost
if delta_cost > 0:
current_state = new_state
current_cost = new_cost
else:
acceptance_prob = math.exp(delta_cost / T)
if random.uniform(0, 1) < acceptance_prob:
current_state = new_state
current_cost = new_cost
i += 1
T = T * alpha
return current_state
```
其中,`problem` 是退火算法的问题描述,包含以下几个函数:
- `initial_state`:初始状态。
- `random_neighbor`:随机生成当前状态的邻居。
- `cost`:评估当前状态的代价。
`Tmax`、`Tmin` 和 `alpha` 分别代表初始温度、最终温度和温度下降率。