龙格库塔.cpp

龙格库塔算法,一个数值分析中的算法,大家先看看吧,有问题及时改正

# include <iostream.h>
double f (double m,double n)
{
	double a=n-2*m/n;
	return a;
}
void main ()
{
	double x,y,h,x1,k1,k2,k3,k4,y1;
	int k,n=1,b=0;
	cout<<"please input x,y,h,k:\n";
	cin>>x>>y>>h>>k;
	for (n=1;n<=k;n++)
	{
		if (b==1)
		{
			x=x1;
			y=y1;
		}
		x1=x+h;
		k1=f(x,y);
		k2=f(x+h/2,y+h*k1/2);
		k3=f(x+h/2,y+h*k2/2);
		k4=f(x1,y+h*k3);
		y1=y+h*(k1+2*k2+2*k3+k4)/6;
		cout<<"x="<<x1<<"    y="<<y1<<endl;
		b=1;
	}
}