坚持局部最优：最小化PSO中的Grienwank函数

Question

我目前正致力于使用(PSO)在简单粒子群优化c++中最小化优化函数。首先优化函数(sphere)产生了良好的结果，但第二个函数(Grienwank)卡住了进入局部微量。 这是我的前两个优化函数的完整c++代码，包括初始参数设置。

#define P    40
#define DIM  10
#define Iter 5000

double gfitness = 100000.0, gbestp[DIM] = { 0 };
int gfitnessindex = 0, y = 0;

class particle
{
public:

    double  x[DIM], v[DIM], fitness, pfitness, pbestpos[DIM]; //pbest
    double xmax, xmin, vmax, vmin, rmax, rmin, iwmax, iwmin, rand1, rand2, c0, c1, w;

    void      init(particle obj[]);
    double    fit(particle obj[]);
    double    f1(particle obj[]);
    double    f2 (particle obj[]);
 void particle::init(particle obj[])
{xmax = 600, xmin = -600;
    vmax = 6.0, vmin = -6.0;
    rmax = 1.0, rmin = 0.0;
    iwmax = .9, iwmin = .4;

    //gfitness    =1000000.0;

    for (int i = 0; i<P; i++)
    {
        for (int j = 0; j<DIM; j++)
        {obj[i].x[j]=xmin + double((xmax - xmin)*rand() / (RAND_MAX + 1.0));
obj[i].v[j] =vmin + double((vmax - vmin)*rand() / (RAND_MAX + 1.0));
            obj[i].pbestpos[j] = 0;
        }
        obj[i].pfitness = 1000000;
    }

    for (int j = 0; j<DIM; j++)
    {
        gbestp[j] = 0;
    }
}double particle::f1(particle obj[])   //   sphere F-01
{
    double count = 0.0;
    for (int j = 0; j<DIM; j++)
    {
        count = count + obj[y].x[j] * obj[y].x[j];
    }
    return count;
}

//....................End of Function F-01....................................................
double particle::f2(particle obj[])   //   Grienwek F-02
{
    double total = 0.0;
    double count = 0.0;
    double prod = 1.0;
    for (int j = 0; j < DIM; j++)
    {
        count = count + obj[y].x[j] * obj[y].x[j];
        prod = prod*cos(obj[y].x[j] / (sqrt(x[j])));
    }
    total = (1 / 4000)*count - prod + 1;
    return total;
}
double particle::fit(particle obj[])
{
    double val2 = 0.0;

    for (int k = 1; k <= Iter; k++)
    {
        for (int l = 0; l<P; l++)
        {
            y = l;
            //val2 = f1(obj);
             val2=f2(obj);
            obj[l].fitness = val2;
            if (obj[l].fitness < obj[l].pfitness)
            {
                obj[l].pfitness = obj[l].fitness;

                for (int j = 0; j<DIM; j++)
                {
                    obj[l].pbestpos[j] = obj[l].x[j];
                }
            }
            if (obj[l].fitness<gfitness)
            {
                gfitnessindex = l;
                gfitness = obj[l].fitness;
                for (int j = 0; j<DIM; j++)
                {
                    gbestp[j] = obj[l].x[j];
                }
            }
        } //,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,End Of Particle

        for (int i = 0; i<P; i++)
        {
            for (int j = 0; j<DIM; j++)
            {
                c0 = 1.49, c1 = 1.49;
                rand1 = rmin + double((rmax - rmin)*rand() / (RAND_MAX + 1.0));
                rand2 = rmin + double((rmax - rmin)*rand() / (RAND_MAX + 1.0));
                w = iwmin + double((iwmax - iwmin)*rand() / (RAND_MAX + 1.0));

                obj[i].v[j] = w*obj[i].v[j] + c0*rand1*(obj[i].pbestpos[j] - obj[i].x[j]) + c1*rand2*(gbestp[j] - obj[i].x[j]);  //obj in 1st bracket   gEout
        if (obj[i].v[j]> vmax)
                    obj[i].v[j] = vmax;
                if (obj[i].v[j]< vmin)
                    obj[i].v[j] = vmin; 
                obj[i].x[j] = (obj[i].x[j] + obj[i].v[j]);
                    if (obj[i].x[j]> xmax)
                    obj[i].x[j] = xmax;
                if (obj[i].x[j]< xmin)
                    obj[i].x[j] = xmin;     
            }
        }
        if (k % 100 == 0)
        {
            cout <<" Iteration"<<", "<<k<<" ,"<< "Particle # " << gfitnessindex << ", " << " gfitness is " << gfitness << endl;
        }
    } //...................................................................................... End of Iteration
    cout << "**************************************************" << endl;
    cout << "Particle # " << gfitnessindex << ", " << " gfitness is " << gfitness << endl;
    cout << "**************************************************" << endl;
       return gfitness;
}
//............................... End of Fitness Function............................................................
void  main()
{   cout << " I am in main function " << endl;
    particle obj1, obj[P];
    obj1.init(obj);
    obj1.fit(obj);
    _getche();
    _getche();
}

这是调用f2(obj)

时的输出

particle # 0 , gfitness is100000
particle # 0 , gfitness is100000
particle # 0 , gfitness is100000
particle # 0 , gfitness is100000
particle # 0 , gfitness is100000