ga-pso java代码
时间: 2023-07-28 19:04:36 浏览: 180
首先,GA-PSO(遗传算法-粒子群优化算法)是一种结合了遗传算法和粒子群优化算法的进化计算算法,主要用于优化问题的求解。下面是一个使用Java语言实现GA-PSO算法的代码示例:
```java
import java.util.Random;
public class GAPSO {
private static final int POPULATION_SIZE = 50; // 种群规模
private static final int MAX_ITERATION = 100; // 最大迭代次数
private static final int DIMENSION = 10; // 问题的维度
private static final double C1 = 2.0; // 学习因子C1
private static final double C2 = 2.0; // 学习因子C2
private static final double V_MAX = 0.5; // 最大速度
private static final double MUTATION_RATE = 0.01; // 变异率
private static final int GENE_LENGTH = 10; // 基因长度
private static final int MAX_BINARY = (int) (Math.pow(2, GENE_LENGTH) - 1); // 最大十进制数
private static final Random random = new Random();
private static class Particle {
int[] velocity = new int[DIMENSION]; // 粒子的速度
int[] position = new int[DIMENSION]; // 粒子的当前位置
double fitness; // 适应度
int[] pBest = new int[DIMENSION]; // 个体最优解
double pBestFitness; // 个体最优解对应的适应度
Particle() {
// 初始化粒子的位置和速度
for (int i = 0; i < DIMENSION; i++) {
position[i] = random.nextInt(MAX_BINARY);
velocity[i] = random.nextInt(MAX_BINARY);
}
}
}
private static class Population {
Particle[] particles; // 种群中的所有粒子
Population() {
particles = new Particle[POPULATION_SIZE];
for (int i = 0; i < POPULATION_SIZE; i++) {
particles[i] = new Particle();
}
}
}
private static double evaluate(int[] position) {
// 计算适应度,这里根据实际情况定义适应度函数
// 适应度越高,解越好
double fitness = 0;
for (int i = 0; i < DIMENSION; i++) {
fitness += position[i];
}
return fitness;
}
private static void updatePBest(Particle particle) {
// 更新个体最优解
double fitness = evaluate(particle.position);
if (fitness > particle.pBestFitness) {
particle.pBestFitness = fitness;
System.arraycopy(particle.position, 0, particle.pBest, 0, DIMENSION);
}
}
private static void updateGBest(Particle[] particles, int[] gBest) {
// 更新全局最优解
double gBestFitness = Double.NEGATIVE_INFINITY;
for (Particle particle : particles) {
if (particle.pBestFitness > gBestFitness) {
gBestFitness = particle.pBestFitness;
System.arraycopy(particle.pBest, 0, gBest, 0, DIMENSION);
}
}
}
private static void updateVelocity(Particle particle, int[] gBest) {
// 更新粒子的速度
for (int i = 0; i < DIMENSION; i++) {
double r1 = random.nextDouble();
double r2 = random.nextDouble();
particle.velocity[i] = (int) (particle.velocity[i] + C1 * r1 * (particle.pBest[i] - particle.position[i])
+ C2 * r2 * (gBest[i] - particle.position[i]));
// 控制速度不超过最大速度
if (particle.velocity[i] > V_MAX) {
particle.velocity[i] = (int) V_MAX;
} else if (particle.velocity[i] < -V_MAX) {
particle.velocity[i] = (int) -V_MAX;
}
}
}
private static void updatePosition(Particle particle) {
// 更新粒子的位置
for (int i = 0; i < DIMENSION; i++) {
particle.position[i] = (int) (particle.position[i] + particle.velocity[i]);
// 控制位置不超过边界
if (particle.position[i] > MAX_BINARY) {
particle.position[i] = MAX_BINARY;
} else if (particle.position[i] < 0) {
particle.position[i] = 0;
}
}
}
public static void main(String[] args) {
Population population = new Population();
int[] gBest = new int[DIMENSION]; // 全局最优解
double[] fitness = new double[POPULATION_SIZE]; // 每个粒子的适应度
for (int iter = 0; iter < MAX_ITERATION; iter++) {
// 更新每个粒子的个体最优解和全局最优解
for (int i = 0; i < POPULATION_SIZE; i++) {
Particle particle = population.particles[i];
updatePBest(particle);
fitness[i] = particle.pBestFitness;
}
updateGBest(population.particles, gBest);
// 更新每个粒子的速度和位置
for (int i = 0; i < POPULATION_SIZE; i++) {
Particle particle = population.particles[i];
updateVelocity(particle, gBest);
updatePosition(particle);
// 根据变异率进行变异
if (random.nextDouble() < MUTATION_RATE) {
particle.position[random.nextInt(DIMENSION)] = random.nextInt(MAX_BINARY);
}
}
// 输出当前迭代的全局最优解的适应度
double gBestFitness = evaluate(gBest);
System.out.println("Iteration " + (iter + 1) + ": " + gBestFitness);
}
}
}
```
以上是一个使用Java语言实现GA-PSO算法的简化版代码。在实际应用中,根据具体的问题和需求,可能需要根据具体情况对算法进行适当的修改和优化。
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