/******************************************************************************
 * Various trigonometric approximations to Pi.
 * 
 * Copyright © 2017 Richard Lesh.  All rights reserved.
 *****************************************************************************/

import org.pureprogrammer.Utils;

public class ComputePi1 {

    public static void main(String[] args) {
        final double PI1 = Math.atan(1.0) * 4.0;
        final double PI2 = Math.atan2(0.0, -1.0);
        final double PI3 = Math.acos(-1.0);
        final double PI4 = 2.0 * Math.acos(0.0);

        System.out.println(Utils.format("pi1: {0:.15f}", PI1));
        System.out.println(Utils.format("abs(pi1 - π): {0:.10e}", Math.abs(PI1 - Math.PI)));
        System.out.println(Utils.format("pi2: {0:.15f}", PI2));
        System.out.println(Utils.format("abs(pi2 - π): {0:.10e}", Math.abs(PI2 - Math.PI)));
        System.out.println(Utils.format("pi3: {0:.15f}", PI3));
        System.out.println(Utils.format("abs(pi3 - π): {0:.10e}", Math.abs(PI3 - Math.PI)));
        System.out.println(Utils.format("pi4: {0:.15f}", PI4));
        System.out.println(Utils.format("abs(pi4 - π): {0:.10e}", Math.abs(PI4 - Math.PI)));
    }
}