trapzint.h

这是一个VC环境下用C++写的变步长梯形求积分算法

#include <iostream.h>
#include <math.h>
class F
{
public:
	virtual double operator()(double x)const=0;
};
class Fun:public F
{
public:
	double operator()(double x)const
	{
		return log(1.0+x)/(1.0+x*x);
	}
};
class Integ
{
public:
	virtual double operator ()(double a,double b,double eps)const=0;
};
class Trapz:public Integ
{
public:
	Trapz(const F&pf):f(pf){}
	double operator()(double a,double b,double eps)const;
private:
	const F&f;
};