来自「收集的C语言算法程序」· 代码 · 共 1 行

#include<iostream.h>//确定要计算的角度值#define A 0.57891//一阶差商的函数声明inline double f(int,int);//二阶差商的函数声明inline double f(int,int,int);//三阶差商的函数声明inline double f(int,int,int,int);//牛顿插值多项式的函数声明double Newton(double);double x[4]={0.4,0.5,0.6,0.7};double y[4]={0.38942,0.47943,0.56464,0.64422};void main(){       cout<<"经用牛顿插值法计算得知\n";       cout<<"sin(0.57891)的近似值为"<<Newton(A)<<endl;}//一阶差商的函数定义inline double f(int m,int n){       return (y[n]-y[m])/(x[n]-x[m]);}//二阶差商的函数定义inline double f(int m,int n,int k){       return (f(n,k)-f(m,n))/(x[k]-x[m]);}//三阶差商的函数定义inline double f(int m,int n,int k,int t){       return (f(n,k,t)-f(m,n,k))/(x[t]-x[m]);}//牛顿插值多项式的函数定义double Newton(double xx){       return y[0]+f(0,1)*(xx-x[0])+f(0,1,2)*(xx-x[0])*(xx-x[1])+f(0,1,2,3)*(xx-x[0])*(xx-x[1])*(xx-x[2]);}