粒子群PSO算法

//作者：Guo R.H

//日期：07.1.2

//    USTC

//  载请说明

 

#include
#include
#include
#include

#define P_num 20          //粒子数目 
#define dim 30
#define low -30           //搜索域范围
#define high 30
#define iter_num 600
#define V_max 20          //速度范围
#define c1 2
#define c2 2
#define w 0.5
#define alp 1
double particle[P_num][dim];           //个体集合
double particle_loc_best[P_num][dim];  //每个个体局部最优向量
double particle_loc_fit[P_num];        //个体的局部最优适应度,有局部最优向量计算而来
double particle_glo_best[dim];         //全局最优向量
double gfit;                           //全局最优适应度,有全局最优向量计算而来 

double particle_v[P_num][dim];         //记录每个个体的当前代速度向量
double particle_fit[P_num];            //记录每个粒子的当前代适应度
  
double fitness(double a[])
{
 int i;
 double sum=0.0;
 for(i=0; i  sum += a[i]*a[i];
//  sum += 100*(a[i+1]-a[i]*a[i])*(a[i+1]-a[i]*a[i])
//    +(a[i]-1)*(a[i]-1);
 return sum;
}

void initial()
{
 int i,j;
 for(i=0; i  for(j=0; j  {
   particle[i][j] = low+(high-low)*1.0*rand()/RAND_MAX;    //初始化群体
   particle_loc_best[i][j] = particle[i][j];               //将当前最优结果写入局部最优集合
   particle_v[i][j] = -V_max+2*V_max*1.0*rand()/RAND_MAX;    //速度
  }
 for(i=0; i {
  particle_fit[i] = fitness(particle[i]);
  particle_loc_fit[i] = particle_fit[i];
 }
 gfit = particle_loc_fit[0];      //找出全局最优
 j=0;
 for(i=1; i {
  if(particle_loc_fit[i]  {
   gfit = particle_loc_fit[i];
   j = i;
  }
 }
 for(i=0; i  particle_glo_best[i] = particle_loc_best[j][i];
}

void renew_particle()
{
 int i,j;
 for(i=0; i  for(j=0; j  {
   particle[i][j] +=  alp*particle_v[i][j];
   if(particle[i][j] > high)
    particle[i][j] = high;
   if(particle[i][j] < low)
    particle[i][j] = low;
  }
}

void renew_var()
{
 int i, j;
 for(i=0; i {
  particle_fit[i] = fitness(particle[i]);
  if(particle_fit[i] < particle_loc_fit[i])      //更新个体局部最优值
  {
   particle_loc_fit[i] = particle_fit[i];
   for(j=0; j    particle_loc_best[i][j] = particle[i][j];
  }
 }
 for(i=0,j=-1; i {
  if(particle_loc_fit[i]  {
   gfit = particle_loc_fit[i];
   j = i;
  }
 }
 if(j != -1)
  for(i=0; i   particle_glo_best[i] = particle_loc_best[j][i];
 for(i=0; i  for(j=0; j  {
   particle_v[i][j] = w*particle_v[i][j]+c1*1.0*rand()/RAND_MAX*(particle_loc_best[i][j]-particle[i][j])
        +c2*1.0*rand()/RAND_MAX*(particle_glo_best[j]-particle[i][j]);
   if(particle_v[i][j] > V_max)
    particle_v[i][j] = V_max;
   if(particle_v[i][j] < -V_max)
    particle_v[i][j] = -V_max;
  }

}

int main()
{
 int i=0;
 srand((unsigned)time(NULL));
 initial();
 while(i < iter_num)
 {
  renew_particle();
  renew_var();
  printf("%lf\n", gfit);
  i++;
 }

 return 0;
}