/****************************************************************************
** COPYRIGHT (C):    1997 Cay S. Horstmann. All Rights Reserved.
** PROJECT:          Practical OO Development with C++ and Java
** FILE:             Approx.java
** PURPOSE:          approximate floating-point equality
** VERSION           1.0
** PROGRAMMERS:      Cay Horstmann (CSH)
** RELEASE DATE:     3-15-97 (CSH)
** UPDATE HISTORY:
****************************************************************************/

package practicaloo;

class Approx
{   public static boolean equal(double x, double y)
    /*  PURPOSE:    tests whether two floating point numbers are approximately equal
        RECEIVES:   x, y - floating point numbers
        RETURNS:    TRUE iff |x-y| approx. 0
    */
    {
        return Math.abs(x - y) / Math.max(Math.abs(x), Math.abs(y)) < EPS;
    }



    public static boolean lessOrEqual(double x, double y)
    /*  PURPOSE:    compares two floating point numbers, allowing for roundoff
        RECEIVES:   x, y - floating point numbers
        RETURNS:    TRUE iff x < y + roundoff
    */
    {
        return (x - y) / Math.max(Math.abs(x), Math.abs(y)) < EPS;
    }

    private static final double EPS = 0.000001;
}