用.NET语言计算股票技术指标BOLL的代码

以下是用.NET语言计算股票技术指标BOLL的代码：

public static void CalculateBoll(double[] close, int n, double k, out double[] mid, out double[] upper, out double[] lower)
{
    mid = new double[close.Length];
    upper = new double[close.Length];
    lower = new double[close.Length];

    double[] ma = new double[close.Length];
    double[] md = new double[close.Length];

    for (int i = 0; i < close.Length; i++)
    {
        double sum = 0;
        for (int j = i - n + 1; j <= i; j++)
        {
            if (j < 0)
            {
                sum += close[0];
            }
            else
            {
                sum += close[j];
            }
        }
        ma[i] = sum / n;

        double sum2 = 0;
        for (int j = i - n + 1; j <= i; j++)
        {
            if (j < 0)
            {
                sum2 += Math.Pow(close[0] - ma[i], 2);
            }
            else
            {
                sum2 += Math.Pow(close[j] - ma[i], 2);
            }
        }
        md[i] = Math.Sqrt(sum2 / n);

        mid[i] = ma[i];
        upper[i] = ma[i] + k * md[i];
        lower[i] = ma[i] - k * md[i];
    }
}

其中，`close`是股票收盘价数组，`n`是计算周期，`k`是标准差倍数，`mid`、`upper`、`lower`分别是计算出的中轨、上轨、下轨数组。