monituihuo.cpp

无约束条件的模拟退火算法

#include <iostream>
#include <cmath>
#include <ctime>
#include <cstdlib>

using namespace std;

const double b = 0.9;
double u = 0;

///.....计算函数的值......////
double Ifunc(double x, double y, double z)
{
	double hsz = 0.0;
	hsz = 50 - pow(5 * x - 2 * y , 2) - pow(x - 7 * y * y + 2 * z * z , 4);
	return hsz;

}

/////..........概率计算.........//////
double glfunc(double w1, double w2, double T)
{
	double p;
	double u = 0;
	double w3 = - 1.00 * abs(w1 - w2);
	u = exp(w3 / (b * T));
	if (u < 1)
		p = u;
	else 
		p = 1;
	return p;

}

void main()
{
	double x = 0 , y = 0 , z = 0 , x_next = 0 , y_next = 0 , z_next = 0 , hsz = 0 , hsz_next = 0 , hsz_max = 0;
	double x_max , y_max , z_max;
	cout << "请输入 x y z 值 : " ;
	cin >> x >> y >> z;
	cout << endl;
	double T = 20000;
	hsz_max = Ifunc(x,y,z);
	do
	{
		hsz = Ifunc(x,y,z);  
		cout << "hsz = " << hsz << endl;//计算初始值
	
		srand(static_cast<unsigned>(time(static_cast<time_t *>(NULL))));
		//进行 y = x + z 变换
		x_next = x + -x * (rand() % 10000)  / 10100.00 ;
		y_next = y + -y * (rand() % 10000)  / 10100.00 ; 
		z_next = z + -z * (rand() % 10000)  / 10100.00 ;
		cout << "x_next = " << x_next << endl;
		cout << "y_next = " << y_next << endl;
		cout << "z_next = " << z_next << endl;
		hsz_next = Ifunc(x_next,y_next,z_next),u = 0.9 * u;
		cout << "hsz_next = " << hsz_next << endl;
		
		//随机选取数r_rand
		double r_rand = 0.01 * (rand() + 500) / 33000.00; 
		cout << "r_rand = " << r_rand << endl;

		double p = glfunc(hsz,hsz_next,T);
		
		///概率接受检验
		
		if (r_rand <= 1)
		{
			x = x_next;
			y = y_next;
			z = z_next;
			hsz = hsz_next;
			

		}
		else
		{
			x_next = x;
			y_next = y;
			z_next = z;
			hsz_next = hsz;	
		
		}
		if(hsz_next > hsz_max)
		{
			x_max = x_next;
			y_max = y_next;
			z_max = z_next;
			hsz_max = hsz_next;
			T = T * b;
		}
		
	cout << endl << endl;
	
	cout << "最大值为 ：" << hsz_max << endl;
	cout << "当取得最大值时" << endl;
	cout << "x_max = " << x_max << endl;
	cout << "y_max = " << y_max << endl;
	cout << "z_max = " << z_max << endl;
	cout << "***************************" << endl;


	getchar();
	}while(T >= 0);
	
	
	
	




}