根据此堆栈问题:How to calculate the rolling average of a C# array list?
您可以像这样在正常列表中取平均值的运行平均值:
List<int> numlist = new List<int>();
List<double> averages = Enumerable.Range(0, numlist.Count - 3).
Select(i => numlist.Skip(i).Take(4).Average()).
ToList();
我的问题:我希望能够在课程列表的特定子集上进行此操作:
public class Data_Raw
{
public DateTime DateDataRaw { set; get; }
public double PriceRaw { set; get; }
public double PercentageReturnsRaw { set; get; }
public Data_Raw(DateTime _dateDataRaw,double _priceRaw, double _percentageReturnsRaw)
{
DateDataRaw = _dateDataRaw; //1
PriceRaw = _priceRaw;
PercentageReturnsRaw = _percentageReturnsRaw;
}
}
List<Data_Raw> myRawData = new List<Data_Raw>();
我想在PriceRaw
的类别列表中计算myRawData
数据的平均值。
编辑:
如果这是PriceRaw
的数据:
myRawData[0].PriceRaw=2
myRawData[1].PriceRaw=3
myRawData[2].PriceRaw=4
myRawData[3].PriceRaw=5
如何获得最近的三个PriceRaw
值的平均值= =(3 + 4 + 5)/ 3 =4。它仅在myRawData.Skip
之后才可用
如果我尝试将跳过附加到myRawData[].PriceRaw.Skip
,则跳过不可用
此堆栈问题使我更接近,但无法弄清楚:Linq query a List of objects containing a list of object
只需在numList
中选择所需的值(请参见第一行):
var numList = myRawData.Select(x => x.PriceRaw).ToList();
List<double> averages = Enumerable.Range(0, numlist.Count - 3).
Select(i => numlist.Skip(i).Take(4).Average()).
ToList();
另一种可能的方式是:
List<double> averages = Enumerable.Range(0, myRawData.Count - 3).
Select(i => myRawData.Skip(i).Take(4).Select(x => x.PriceRaw).Average()).
ToList();
我认为,如果您使用理解语法,对它进行管理会更容易。即:
void Main()
{
List<Data_Raw> myRawData = new List<Data_Raw> {
new Data_Raw(new DateTime(2018,1,1), 2, 1),
new Data_Raw(new DateTime(2018,1,2), 3, 1),
new Data_Raw(new DateTime(2018,1,3), 4, 1),
new Data_Raw(new DateTime(2018,1,4), 5, 1),
new Data_Raw(new DateTime(2018,1,5), 6, 1),
new Data_Raw(new DateTime(2018,1,6), 7, 1),
new Data_Raw(new DateTime(2018,1,7), 8, 1),
};
var groupSize = 3;
var result = from i in Enumerable.Range(0, myRawData.Count() - (groupSize - 1))
let myGroup = myRawData.Skip(i).Take(groupSize)
select new
{
Values = string.Join(",", myGroup.Select(rd => rd.PriceRaw.ToString())),
Average = myGroup.Average(rd => rd.PriceRaw)
};
}
public class Data_Raw
{
public DateTime DateDataRaw { set; get; }
public double PriceRaw { set; get; }
public double PercentageReturnsRaw { set; get; }
public Data_Raw(DateTime _dateDataRaw, double _priceRaw, double _percentageReturnsRaw)
{
DateDataRaw = _dateDataRaw; //1
PriceRaw = _priceRaw;
PercentageReturnsRaw = _percentageReturnsRaw;
}
}