如何简化计算标准差的下列代码

Question

在我开始之前，我花了很多时间去寻找答案。似乎最有参考价值的方法就是这里，http://www.developer.com/print.php/3794146。我不太懂如何优化。见下文。

public void CalculateStdDev()
{
    arrayItemCount = 0; // integer
    average = 0; // double
    double itemsSum = 0;
    double[] values = new double[DS.Tables[0].Rows.Count];
    double[] deviations = new double[DS.Tables[0].Rows.Count];
    double[] squareDeviations = new double[DS.Tables[0].Rows.Count];
    double squareDeviationsSum = 0;
    double squareDeviationsAverage = 0;
    stdDeviation = 0; // double

    for (int i = 0; i < DS.Tables[0].Rows.Count; i++)
    {
        if (DS.Tables[0].Rows[i].ItemArray.GetValue(1).ToString() != "")
        {
            values[arrayItemCount] = Convert.ToDouble(DS.Tables[0].Rows[i].ItemArray.GetValue(1));
            itemsSum += Convert.ToDouble(DS.Tables[0].Rows[i].ItemArray.GetValue(1));
            arrayItemCount += 1;
        }
    }
    average = itemsSum / arrayItemCount;
    for (int i = 0; i < arrayItemCount; i++)
    {
        deviations[i] = Math.Abs(values[i] - average);
        squareDeviations[i] = deviations[i] * deviations[i];
        squareDeviationsSum += squareDeviations[i];
    }
    squareDeviationsAverage = squareDeviationsSum / Convert.ToDouble(arrayItemCount - 1);
    stdDeviation = Math.Round(Convert.ToDouble(Math.Sqrt(squareDeviationsAverage)), 3);
}

Answer 1

如果方法计算标准解算，它应该返回值，而不是分配全局变量或实例变量。

致以敬意，