talor.cpp

Taylor方法

#include<iostream>
#include<math.h>

using namespace std;
double f(double t,double y)
{
	return -9.8-0.002*y*fabs(y)/0.11;
}
double fx(double t,double y)
{
	if(y>=0)
	{
		return -0.004*y*(-9.8-0.002*y*y/0.11)/0.11;
	}
	else 
	{
		return 0.004*y*(-9.8+0.002*y*y/0.11)/0.11;
	}
}

int main()
{
	double w[100];
	w[0]=8.0;
	double h=0.1;
	for(int i=0;i<20;i++)
	{
		cout<<w[i]<<endl;
		double t=i*0.1;
		w[i+1]=w[i]+h*(f(t,w[i])+h*fx(t,w[i])/2);
	}
	return 0;
}