编写程序用人工免疫算法求解函数f(x)=x1^2+x2^2-5x1x2-2x1-4x2+10的极值
时间: 2023-05-19 17:06:25 浏览: 208
一个用于求函数极值的遗传算法程序.zip_函数极值_算法求极值_遗传 极值_遗传算法 _遗传算法 极值
非常感谢您的提问,我可以回答这个编程类的问题。以下是用人工免疫算法求解函数f(x)=x1^2 x2^2-5x1x2-2x1-4x2 10的极值的程序代码:
```python
import numpy as np
def f(x):
return x[0]**2 * x[1]**2 - 5*x[0]*x[1] - 2*x[0] - 4*x[1] + 10
def immune_algorithm(f, bounds, pop_size=50, max_iter=1000, beta=0.1, gamma=0.1, mu=0.1):
dim = len(bounds)
pop = np.random.uniform(bounds[:, 0], bounds[:, 1], size=(pop_size, dim))
fitness = np.array([f(p) for p in pop])
best_idx = np.argmin(fitness)
best = pop[best_idx]
for i in range(max_iter):
# clone
num_clones = np.round(beta * pop_size).astype(int)
clones = np.repeat(pop, num_clones, axis=0)
# hypermutation
clones += np.random.normal(0, gamma, size=clones.shape)
clones = np.clip(clones, bounds[:, 0], bounds[:, 1])
# selection
clone_fitness = np.array([f(p) for p in clones])
sort_idx = np.argsort(clone_fitness)
pop = clones[sort_idx[:pop_size]]
fitness = clone_fitness[sort_idx[:pop_size]]
# mutation
num_mutants = np.round(mu * pop_size).astype(int)
mutants = np.random.uniform(bounds[:, 0], bounds[:, 1], size=(num_mutants, dim))
mutant_fitness = np.array([f(p) for p in mutants])
# replace worst individuals
sort_idx = np.argsort(fitness)
pop[sort_idx[-num_mutants:]] = mutants[mutant_fitness > fitness[sort_idx[-num_mutants:]]]
fitness[sort_idx[-num_mutants:]] = mutant_fitness[mutant_fitness > fitness[sort_idx[-num_mutants:]]]
# update best
best_idx = np.argmin(fitness)
if fitness[best_idx] < f(best):
best = pop[best_idx]
return best, f(best)
bounds = np.array([[-5, 5], [-5, 5]])
best, value = immune_algorithm(f, bounds)
print("Best solution:", best)
print("Best value:", value)
```
这个程序使用了人工免疫算法来求解函数f(x)的极值。算法的基本思想是通过克隆、超突变和选择等操作来搜索解空间,并通过突变来保持种群的多样性。最终,算法返回找到的最优解及其对应的函数值。
请注意,这个程序仅供参考,实际应用中可能需要根据具体问题进行调整和优化。
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