package test;

import java.text.NumberFormat;
import java.text.DecimalFormat;

public class NewtonRaphson {
    static final double DIFFERENCE = 0.00005;
    double n;
    double x;
    double derivative;
    double function;
    double xold;
    double xnew;
    int i;

    public NewtonRaphson(double n2, int x2) {
        n=n2;
        x=x2;
        function = Math.pow(n, 2)-x;
        derivative = 2*n;
        xnew=n-function/derivative;
        xold=0;
    }

    boolean positive() {
        return (n >= 0);
    }

    public double findXNew(double xold2) {
        function = Math.pow(xold2, 2)-x;
        derivative = 2*xold2;
        return xold2-function/derivative;
    }

    public void findSqRtA() {
        i=0;
        while(Math.abs(xnew-xold)> DIFFERENCE) {
            xold=xnew;
            xnew=findXNew(xold);
            i++;
            System.out.println(this);
        }
        System.out.println("\nIteration completed, difference is less than 0.00005");
    }

    public String toString() {
        NumberFormat nf = NumberFormat.getInstance(); DecimalFormat df = (DecimalFormat)nf;
        df.applyPattern("0.00000000");

        return "The approximate value of the square root of "+x+" is " + xnew + "\n" +

        "The number of iterations is " + i;
    }
}