Compare two double type variables within epsilon

 
public class Main {
  final static double EPSILON = 0.0000001;
  public static void main(String[] argv) {
    double da = 3 * .3333333333;
    double db = 0.99999992857;

    if (da == db) {
      System.out.println("Java considers " + da + "==" + db);
    } else if (equals(da, db, 0.0000001)) {
      System.out.println("True within epsilon " + EPSILON);
    } else {
      System.out.println(da + " != " + db);
    }

    double d1 = Double.NaN;
    double d2 = Double.NaN;
    if (d1 == d2)
      System.err.println("Comparing two NaNs incorrectly returns true.");
    if (!new Double(d1).equals(new Double(d2)))
      System.err.println("Double(NaN).equal(NaN) incorrectly returns false.");
  }

  public static boolean equals(double a, double b, double eps) {
    if (a==b) return true;
    return Math.abs(a - b) < eps;
  }
  public static boolean equals(double a, double b) {
    if (a==b) return true;
    return Math.abs(a - b) < EPSILON * Math.max(Math.abs(a), Math.abs(b));
  }
}
  

True within epsilon 1.0E-7