变色龙群优化算法的代码

变色龙群优化算法（Chameleon Optimization Algorithm，简称COA）是一种模拟生物变色龙的群体行为来解决优化问题的算法。以下是一份 Python 代码实现：

import random
import math

class COA:
    def __init__(self, dim, size, max_iter, lb, ub, fun):
        self.dim = dim
        self.size = size
        self.max_iter = max_iter
        self.lb = lb
        self.ub = ub
        self.fun = fun
        self.best_solution = None
        self.best_fitness = float('inf')
        
    def init_population(self):
        self.population = []
        for i in range(self.size):
            solution = []
            for j in range(self.dim):
                solution.append(random.uniform(self.lb, self.ub))
            fitness = self.fun(solution)
            if fitness < self.best_fitness:
                self.best_solution = solution
                self.best_fitness = fitness
            self.population.append((solution, fitness))
            
    def update(self):
        for i in range(self.size):
            r = random.randint(0, self.size-1)
            while r == i:
                r = random.randint(0, self.size-1)
            j = random.randint(0, self.dim-1)
            d = abs(self.population[r][0][j] - self.population[i][0][j])
            x = self.population[i][0][j] - self.population[i][1]*d*(self.population[r][0][j]-self.population[i][0][j])
            if x < self.lb:
                x = self.lb
            elif x > self.ub:
                x = self.ub
            solution = self.population[i][0]
            solution[j] = x
            fitness = self.fun(solution)
            if fitness < self.best_fitness:
                self.best_solution = solution
                self.best_fitness = fitness
            self.population[i] = (solution, fitness)
            
    def optimize(self):
        self.init_population()
        for i in range(self.max_iter):
            self.update()
        return self.best_solution, self.best_fitness

其中，`dim` 是问题的维度，`size` 是种群大小，`max_iter` 是最大迭代次数，`lb` 和 `ub` 分别是问题的下界和上界，`fun` 是目标函数。`init_population` 方法用于初始化种群，`update` 方法用于更新种群，`optimize` 方法用于运行算法并返回最优解和最优值。