复制内容到剪贴板
代码:
#include<iostream.h>
#include<math.h>
int n;
float f(float);
void main()
{
float s;
float AutoTrap(float (*)(float),float,float);
s=AutoTrap(f,0.0,1.0);
cout<<"T("<<n<<")="<<s<<endl;
}
float AutoTrap(float (*)(float),float a,float b)
{
int i;
float x,s,h=b-a;
float t1,t2=h/2.0*(f(a)+f(b));
n=1;
do{
s=0.0;
t1=t2;
for(i=0;i<=n-1;i++)
{
x=a+i*h+h/2;
s+=f(x);
}
t2=(t1+s*h)/2.0;
n*=2;
h/=2.0;
}while( fabs(t2-t1)>1e-6);
return t2;
}
float f(float x)
{
return 1/(1+x*x);
}
//用变步长梯形法计算积分积分只要将函数定义为
/*float f(float x)
{
if(x==0)
return 1;
else
return sin(x)/x;
}*/
