//ODE_Treanor.cpp	 積分一步特雷納法

#include <iostream>							//輸入輸出流頭文件
#include "OrdinaryDifferentialEguation.h"	///求解常微分方程(組)頭文件
using namespace std;						//名字空間

void main(void)
{	
	double y[3] = {1.0, 0.0, -1.0}, t(0.0), h(0.001);
	valarray<double> vy(y, 3);
	
  	cout.setf(ios::fixed);	//輸出數(shù)據(jù)為定點(diǎn)法
	cout.precision(6);		//精度6位

	cout << "t = " << t << endl;

	for(int j=0; j<3; j++)
		cout << "    y(" << j << ") = " << y[j] << "\t";
	cout << endl;

	for(int i=0; i<10; i++)
	{
		ODE_Treanor(t,h,vy);
		t = t + h;
		cout << "t = " << t << endl;
		for(j=0; j<3; j++)
			cout << "    y(" << j << ") = " << vy[j] << "\t";
		cout << endl;
    }
	cout << endl;
}

//計(jì)算微分方程組中各方程右端函數(shù)值
template <class _Ty>
void FunctionValueT(_Ty t, valarray<_Ty>& y, valarray<_Ty>& d)
{
	int n = y.size();	//微分方程組中方程的個(gè)數(shù)，也是未知函數(shù)的個(gè)數(shù)

    d[0]=-21.0*y[0]+19.0*y[1]-20.0*y[2];
    d[1]=19.0*y[0]-21.0*y[1]+20.0*y[2];
    d[2]=40.0*y[0]-40.0*y[1]-40.0*y[2];
}