Beyond_Beyaan.Utility.LogOnePlusX C# (CSharp) Метод

        private static double LogOnePlusX(double x)
        {
            if (x <= -1.0)
            {
                string msg = String.Format("Invalid input argument: {0}", x);
                throw new ArgumentOutOfRangeException(msg);
            }

            if (Math.Abs(x) > 1e-4)
            {
                // x is large enough that the obvious evaluation is OK
                return Math.Log(1.0 + x);
            }

            // Use Taylor approx.
            // log(1 + x) = x - x^2/2 with error roughly x^3/3
            // Since |x| < 10^-4, |x|^3 < 10^-12,
            // relative error less than 10^-8

            return (-0.5 * x + 1.0) * x;
        }