newt0.cpp

y=x+log(x)-2.2 的一种算法

#include "math.h"
#include "stdio.h"
#include "newt.h"
void main()
{
	int js,k;
	double x,eps;
	void newtf(double,double []);
	eps=0.000001; js=60; x=1.5;
	k=newt(&x,eps,js,newtf);
	if(k>=0)
		printf("k=%d x=%13.7e\n",k,x);
	printf("\n");
	getchar();
}

void newtf(double x,double y[])
{
	y[0]=x*x*(x-1.0)-1.0;
	y[1]=3.0*x*x-2.0*x;
	return;
}