/*==================================================================
Written by:		Roberto Mojica
Last revision:	10 February 2007
--------------------------------------------------------------------
Programs that implement the Newton's method to find a root of a 
single variable function f(x) around some value of x.
==================================================================*/
#include <iostream>
#include <iomanip>
#include <cmath>
using namespace std;

//configuration
#define PI 3.1415926535897932385
#define MAX_NUM_OF_ITERATIONS 10000
#define STARTING_POINT 1
#define EPS 1.0e-6

#define _Fx(X) exp(X)*log(X)-cos(X*X)
#define _Fpx(X) exp(X)/X +exp(X)*log(X)+2*X*sin(X*X)

//#define _Fx(X) log(X*X+2)*cos(X)+sin(X)
//#define _Fpx(X) -log(X*X+2)*sin(X)+(2*X)/(X*X+2)+cos(X)

//#define _Fx(X) exp(X)-sin(PI*X/3)
//#define _Fpx(X) exp(X)-PI*cos(PI*X/3)/3

//#define _Fx(X) X*X-6*X+9
//#define _Fpx(X) 2*X-6

#define COL_WIDTH 20
void f(double x,double &fx,double &fpx) {fx=(_Fx(x)); fpx=(_Fpx(x)); return;}
int main() {
	cout.setf(ios::fixed | ios::showpoint | ios::right);
    cout.precision(10);
	cout << ::setw(COL_WIDTH) << "x" << std::setw(COL_WIDTH) << "fx"
			<< ::setw(COL_WIDTH) << "fpx" << endl;
	double x=STARTING_POINT,xc,fx,fpx;
	int iterations=0;
	do {
		f(x,fx,fpx);
		x=xc=x-fx/fpx;
		cout << ::setw(COL_WIDTH) << x << ::setw(COL_WIDTH) << fx
			<< ::setw(COL_WIDTH) << fpx << ::setw(6) << iterations << endl;
	} while(fabs(fx) >= EPS && (iterations++) <= MAX_NUM_OF_ITERATIONS);
	cout << endl << xc << endl;
    system("pause");
	return iterations;	
}