Fan.Sys.Double.doubleValue C# (CSharp) Method

        public override double doubleValue()
        {
            return val;
        }

        public static bool approx(double self, double that, Double tolerance)
        {
            // need this to check +inf, -inf, and nan
              if (compare(self, new Double(that)) == 0) return true;

              double t;
              if (tolerance == null)
            t = Math.Min(Math.Abs(self/1e6), Math.Abs(that/1e6));
              else
            t = tolerance.doubleValue();
              return Math.Abs(self - that) <= t;
        }