www.pudn.com > lagrange.rar > Lagrage.cpp

#include 
#include 
#include 
#include 
#include 
#include 
#define PI 3.14159265358979 
double fx( double x ) 
{ 
	double tmp=x*x; 
	tmp+=1.0; 
	return( 1.0/tmp ); 
} 
double Lagrange( int n, double x[], double y[], double val ) 
{ 
	double lx=0.0; 
	double tmp; 
	int i; 
	int j; 
	double mid1,mid2,mid3; 
	for( i=0; i<=n; i++ ) 
	{ 
		tmp=1.0; 
		for( j=0; j0 ) 
		return tmp; 
	else 
		return -tmp; 
} 
void main( void ) 
{ 
	double val; 
	double max; 
	double error; 
	int i,j; 
	double mid; 
	ofstream file( "result.txt" ); 
	cout<<"第1组：插值节点为 xi=-5+10*i/N"<