/**
   A class for useful numeric methods.
*/

public class Numeric
{  /**
      Tests whether two floating-point numbers are
      equal, except for a roundoff error
      @param x a floating-point number
      @param y a floating-point number
      @return true if x and y are approximately equal
   */
   public static boolean approxEqual(double x, double y)
   {  final double EPSILON = 1E-14;
      double xymax = Math.max(Math.abs(x), Math.abs(y));
      return Math.abs(x - y) <= EPSILON * xymax;
   }
   // more numeric methods can be added here
}