VS2005中强大的集合统计方法,JDK没有的.

       以下为项目代码的节选:

/// 得到标准差
        /// </summary>
        public virtual double? Standard_deviation
        {
            get
            {
                double? value = 0;
                System.Data.DataTable dt = new System.Data.DataTable();
                dt.Columns.Add("value", typeof(double));
                for (int i = 0; i < valueList.Count; i++)
                {
                    if (scop1 != null)
                    {
                        if (valueList[i].Value < scop1)
                            continue;
                    }
                    if (scop2 != null)
                    {
                        if (valueList[i].Value > scop2)
                            continue;
                    }
                    DataRow dr = dt.NewRow();
                    dr["value"] = valueList[i].Value;
                    dt.Rows.Add(dr);
                }
                Object obj = dt.Compute("StDev(value)", "");
                try
                {
                    value = Convert.ToDouble(obj);
                }
                catch { }
                return value;
            }
        }

        /// <summary>
        /// 得到方差
        /// </summary>
        public virtual double? Variance
        {
            get
            {
                double? value = 0;
                System.Data.DataTable dt = new System.Data.DataTable();
                dt.Columns.Add("value", typeof(double));
                for (int i = 0; i < valueList.Count; i++)
                {
                    if (scop1 != null)
                    {
                        if (valueList[i].Value < scop1)
                            continue;
                    }
                    if (scop2 != null)
                    {
                        if (valueList[i].Value > scop2)
                            continue;
                    }
                    DataRow dr = dt.NewRow();
                    dr["value"] = valueList[i].Value;
                    dt.Rows.Add(dr);
                }
                Object obj = dt.Compute("Var(value)", "");
                try
                {
                    value = Convert.ToDouble(obj);
                }
                catch { }
                return value;
            }
        }

具体参考[url] http://blog.csdn.net/smartsmile2012/article/details/8309664[/url]