C# 蒙特卡洛模拟

请问我的for循环是哪里出现问题了呀，出来的结果sum_CT一直是矩阵某一行最右列数值的100倍，但sum_CT应该是矩阵最右列所有数之和。
            double sum_CT, sum_CT2, call_value, SD, SE;
            double[,] matrix = new double[(int) m, (int) N+1];
            double[] arr = new double[(int)m];
            sum_CT = 0;
            sum_CT2 = 0;

            for (i = 0; i <= m - 1; i++)
            {
                matrix[i, 0] = S0;
               
                for (j = 0; j <= N-1; j++)
                {

                    matrix[i, j+1] = matrix[i, j] * Math.Exp(nudt + sigsdt * epsilon); //epsilon is a normally distributed randomvariable
  
                }

                matrix[i, (int)N] = Math.Max(0, matrix[i, (int)N] - K);

                sum_CT = sum_CT + matrix[i, (int)N];
                sum_CT2 += matrix[x, (int)N] * matrix[x, (int)N];
            }

            call_value = (sum_CT * Math.Exp(-miu * T))/m;
            SD = Math.Sqrt((sum_CT2 - sum_CT * sum_CT / m) * Math.Exp(-2 * miu * T) / (m - 1));
            SE = SD / Math.Sqrt(m);
            var result = Tuple.Create<double, double>(sum_CT, matrix[2, (int)N]);
            return result;
        }
结果：（1868.33678， 18.6833678）

[此贴子已经被作者于2021-2-14 13:52编辑过]