请教一下, 有些软件中的几日和的算法

//历史价格集合

            var list = dal.GetModelList(dal.SerialSafeSearchkey(mo)).OrderByDescending(x => x.PriceDateTime);

            System.Diagnostics.Debug.WriteLine("GetModelList时间:"+ t.GetElapsedTime());

            //股票集合

            List<Model.stockcodelist> stlist = new List<Model.stockcodelist>();

            foreach (var item in StockCodeList)

            {

                string code = item.Substring(2);

                //当前股票价格集

                var temp = list.Where(x => x.StockCode == code);

                if (temp.Count() > 0)

                {

                    Model.StockHistoryPrices_MD now = temp.ElementAt(0);

                    //三日数据集

                    var threeq = temp.Take(3);

                    //5日数据集

                    var fiveq = temp.Take(5);

                    //七日数据集 

                    var sevenq = temp.Take(7);

                    //十日数据集

                    var tenq = temp.Take(10);



                    stlist.Add(new

                    Model.stockcodelist

                    {

                        stockcode = code,

                        data = now.PriceDateTime,

                        price = now.EndPrice,

                        ChangePrice = now.ChangePrice,

                        DailyVolume = now.DailyVolume,

                        TurnoverTotal = now.TurnoverTotal,

                        OfPrice = now.OfPrice

                        ,

                        threeDailyVolume = threeq.Sum(x => x.DailyVolume),

                        threeTurnoverTotal =threeq.Sum(x => x.TurnoverTotal),

                        threeOfPrice = threeq.Last().EndPrice / now.EndPrice - 1,

                        threeprice = threeq.Last().EndPrice,

                        threeChangePrice = now.EndPrice - threeq.Last().EndPrice

                        ,

                        fiveDailyVolume = fiveq.Sum(x => x.DailyVolume),

                        fiveTurnoverTotal = fiveq.Sum(x => x.TurnoverTotal),

                        fiveOfPrice = fiveq.Last().EndPrice / now.EndPrice - 1,

                        fiveprice = fiveq.Last().EndPrice,

                        fiveChangePrice = now.EndPrice - fiveq.Last().EndPrice

                        ,

                        sevenDailyVolume = sevenq.Sum(x => x.DailyVolume),

                        sevenTurnoverTotal = sevenq.Sum(x => x.TurnoverTotal),

                        sevenOfPrice = sevenq.Last().EndPrice / now.EndPrice - 1,

                        sevenprice = sevenq.Last().EndPrice,

                        sevenChangePrice = now.EndPrice - sevenq.Last().EndPrice

                        ,

                        tenDailyVolume = tenq.Sum(x => x.DailyVolume),

                        tenTurnoverTotal = tenq.Sum(x => x.TurnoverTotal),

                        tenOfPrice = tenq.Last().EndPrice / now.EndPrice - 1,

                        tenprice = tenq.Last().EndPrice,

                        tenChangePrice = now.EndPrice - tenq.Last().EndPrice

                        ,

                        tenminprice = temp.Take(10).Min(x => x.MinimumPrice),

                        tenmaxprice = temp.Take(10).Max(x => x.MaximumPrice)



                    });

                }

            }