二分法.txt

数值分析中不动点迭代的算法

#include <stdio.h>
#include <math.h>
#define f(x) x*x*x-x-1
main()
{double a=1,b=1.5,x,m;
int k=0;
if(f(a)>0,f(b)<0)
{m=a;
a=b;
b=m;}
if(f(a)*f(b)>0)
printf("no answer!");
else
{printf("k     a            b            x\n");
while(f(a)*f(b)<0&&fabs(b-a)>0.005)
{
x=(a+b)/2;
if(f(x)<0)
a=x;
else if(f(x)>0)
b=x;
printf("%d  %lf    %lf     %lf\n",k,a,b,x);
k++; }}}