Encog.MathUtil.LIBSVM.Solver.calculate_rho C# (CSharp) Method

        internal virtual double calculate_rho()
        {
            double r;
            int nr_free = 0;
            double ub = INF, lb = - INF, sum_free = 0;
            for (int i = 0; i < active_size; i++)
            {
                double yG = y[i]*G[i];

                if (is_lower_bound(i))
                {
                    if (y[i] > 0)
                        ub = Math.Min(ub, yG);
                    else
                        lb = Math.Max(lb, yG);
                }
                else if (is_upper_bound(i))
                {
                    if (y[i] < 0)
                        ub = Math.Min(ub, yG);
                    else
                        lb = Math.Max(lb, yG);
                }
                else
                {
                    ++nr_free;
                    sum_free += yG;
                }
            }

            if (nr_free > 0)
                r = sum_free/nr_free;
            else
                r = (ub + lb)/2;

            return r;
        }