/// 
        /// 求出数据平均值,并保留三位小数        /// 
        /// 数据集合        /// 
             public static double average(List
     
       Valist)        {            double sum = 0;            foreach (double d in Valist)            {                sum = sum + d;            }            double revl = System.Math.Round(sum / Valist.Count, 3);            return revl;        }        /// 
      
        /// 求数据集合标准差        /// 
        /// 
              /// 
              public static double stdev(List
      
        ValList)        {            double avg = average(ValList);            double sumstdev = 0;            foreach (double d in ValList)            {                sumstdev = sumstdev + (d - avg) * (d - avg);            }            double stdeval = System.Math.Sqrt(sumstdev);            return System.Math.Round(stdeval, 3);        }        /// 
       
        /// 相关系数,要求两个集合数量必须相同        /// 
        /// 
       数组一        /// 
       数组二        /// 
               public double correl(List
       
         array1, List
        
          array2)        {            //数组一            double avg1 = average(array1);            double stdev1 = stdev(array1);            //数组二            double avg2 = average(array2);            double stdev2 = stdev(array2);            double sum = 0;            for (int i = 0; i < array1.Count && i < array2.Count; i++)            {                sum = sum + ((array1[i] - avg1) / stdev1) * ((array2[i] - avg2) / stdev2);            }            return Math.Round(sum, 3);        }