/// <summary>
/// 计算出信号的AC成分以及DC成分(单位：RMS)
/// </summary>
/// <param name="signalData">信号来源</param>
/// <param name="acTerm">AC成分</param>
/// <param name="dcTerm">DC成分</param>
public static void EstimateACDC(double[] signalData, out double acTerm, out double dcTerm)
{
double[] inputData = new double[signalData.Length];
double[] acData = new double[signalData.Length];
double[] hann_weighting = Window.Hann(signalData.Length);
double coeff_cg = 0.5; // cg=0.5, compensation for Hanning windowing
double coeff_enbw = 1.5; // enbw=1.5, compensation for Hanning windowing
//DC term extraction
//Hanning windowing the signal
ArrayCalculation.Multiply(hann_weighting, signalData, ref inputData);
//Get the mean value and compensated by the cg coeff
dcTerm = Statistics.Mean(inputData) / coeff_cg;
//AC term extraction
Buffer.BlockCopy(signalData, 0, inputData, 0, signalData.Length * sizeof(double));
//Substract from the dc term
ArrayCalculation.SubtractOffset(ref inputData, dcTerm);
//Hanning windowing the signal
ArrayCalculation.Multiply(hann_weighting, inputData, ref acData);
//Get the variance data, compensated by coeff , and sqrt to derive ac term
acTerm = Math.Sqrt(Statistics.Variance(acData) / (coeff_cg * coeff_cg * coeff_enbw));
}
public virtual void Multiply(short[] src1, short[] src2, ref short[] dest)
{
ArrayCalculation.Multiply(src1, src2, ref dest);
}
public virtual void Multiply(float[] src1, float[] src2, ref float[] dest)
{
ArrayCalculation.Multiply(src1, src2, ref dest);
}
public virtual void Multiply(double[] src1, double[] src2, ref double[] dest)
{
ArrayCalculation.Multiply(src1, src2, ref dest);
}
