12.cpp

优化设计的坐标轮换法

#include"iostream.h"
#include"stdio.h"
#include"math.h"

class vector
{
public:
	vector(){ x=y=0;}
	vector(double i,double j ){ x=i,y=j;}
   double FunctionValue ( );
   vector operator +(const vector &v);
public:
   double x,y;  
};
double vector::FunctionValue ( )
{ 
    return 2*x*x+3*y*y-8*x+10;
} 

inline  vector vector::operator +(const vector &v)
{ 
	return vector(x+v.x,y+v.y);
}

vector StedpOne(vector FirstX,double a,double judger,int n);

void main()
{
    vector Xstart(1,2),Xend;   
    Xend=StedpOne(Xstart,0.5,0.3,2);
    cout<<"X1 = "<<Xend.x<<endl;
	cout<<"X2 = "<<Xend.y<<endl;
	cout<<"F(X) = "<<Xend.FunctionValue()<<endl;
}   
vector StedpOne(vector FirstX,double a,double judger,int n)
{
	double FirstF=FirstX.FunctionValue();
	vector e[3],X;
    int j,k;
	e[1].x=1,e[1].y=0,e[2].x=0,e[2].y=1;
	X.x=0,X.y=0;
	double TempF,aa;
	a = 2*a;
	do
	{ 
		a =0.5*a;
	do
	{
		  j=1,k=0;
	      do
		  {
			  X.x=FirstX.x+a*e[j].x,X.y=FirstX.y+a*e[j].y;
			  TempF=X.FunctionValue();
			  if(TempF<FirstF)
			  {
		          aa = a;
			  }
	          else
			  {
           	      X.x=FirstX.x-a*e[j].x,X.y=FirstX.y-a*e[j].y;
		          TempF=X.FunctionValue();
			      if(TempF<FirstF)
				  {
				      aa=-a;
				  }
			      else
				  {
					  goto jump2;
				
				  }
			  }
jump1:		  X.x=FirstX.x+a*e[j].x,X.y=FirstX.y+a*e[j].y;
			  TempF=X.FunctionValue();
              if(TempF<FirstF)
			  {
				  FirstF = TempF;
				  aa=2*aa;
				  goto jump1;
			  }
			  else
			  {
                  FirstX.x=FirstX.x+0.5*aa*e[j].x,FirstX.y=FirstX.y+0.5*aa*e[j].y;
				  k=1;
			  }
jump2:             j=j+1;
		  }while(j<=n);
	}while(k!=0);
	}while(a>judger);
	return FirstX;
}