计算通用对象列表的标准偏差[重复]

Question

我是一个 c# 菜鸟，但我真的需要专业人士的帮助。我正在为一个项目使用 Visual Studio 2005，所以我没有 math.linq 我需要计算通用对象列表的标准偏差。该列表仅包含一个浮点数列表，没有什么太复杂的。但是我以前从来没有这样做过，所以我需要有人告诉我以前计算过通用列表的标准偏差。这是我尝试开始的代码：

//this is my list of objects inside. The valve data just contains a bunch of floats.
public class ValveDataResults
{
    private List<ValveData> m_ValveResults;

    public void AddValveData(ValveData valve)
    {
        m_ValveResults.Add(valve);
    }

    //this is the function where the standard deviation needs to be calculated:
    public float LatchTimeStdev()
    {
        //below this is a working example of how to get an average or mean
        //of same list and same "LatchTime" that needs to be calculated here as well. 
    }

    //function to calculate average of latch time, can be copied for above st dev.
    public float LatchTimeMean()
    {
        float returnValue = 0;
        foreach (ValveData value in m_ValveResults)
        {
            returnValue += value.LatchTime; 
        }
        returnValue = (returnValue / m_ValveResults.Count) * 0.02f;
        return returnValue;
    }
}

“Latch Time”是插入到 m_ValveResults 列表中的“ValveData”对象的浮点对象。

就是这样。任何帮助将不胜感激。谢谢

Answer 1

试试

public float LatchTimeStdev()
{
    float mean = LatchTimeMean();
    float returnValue = 0;
    foreach (ValveData value in m_ValveResults)
    {
        returnValue += Math.Pow(value.LatchTime - mean, 2); 
    }
    return Math.Sqrt(returnValue / m_ValveResults.Count-1));
}

它与 LINQ 中给出的答案相同，但没有 LINQ :)