public double[] PowerSpectralDensity(double[] d, WindowBase window, double fs, double maxSignalAmpl)
{
Complex[] spec = DoFFT(d, window);
double[] y = new double[spec.Length];
double max = Double.MinValue;
for (int i = 0; i < spec.Length; i++)
{
y[i] = 20 * Math.Log10(spec[i].Abs);
if (y[i] > max)
{
max = y[i];
}
}
if (double.NaN.CompareTo(maxSignalAmpl) == 0)
{
ArrayMath.Add(ref y, -max);
}
else
{
max = 20 * Math.Log10(maxSignalAmpl / 2);
ArrayMath.Add(ref y, -max);
}
return(y);
}
public Complex[] DoFFT(double[] d, WindowBase window)
{
double M = d.Length;
double[] dwindow = window.Calc((int)M);
ArrayMath.Multiply(ref d, ref dwindow);
Complex[] fft = Run(d);
Complex[] spec = new Complex[fft.Length / 2];
for (int i = 1; i < fft.Length / 2 + 1; i++)
{
spec[i - 1].Real = fft[i].Real * 2 / M;
spec[i - 1].Imag = fft[i].Imag * 2 / M;
}
return(spec);
}
public void DynamicParameters(List <double> d, WindowBase window,
double fs, double f0, double fmin, double fmax, bool remove_dc, out double snr, out double sndr, out double enob)
{
double dc_offset = 0;
if (remove_dc)
{
dc_offset = ArrayMath.Sum(d.ToArray()) / d.Count;
}
if (dc_offset != 0)
{
for (int i = 0; i < d.Count; i++)
{
d[i] -= dc_offset;
}
}
Complex[] spec = DoFFT(d, window);
snr = SignalNoise(spec, d.Count, fs, f0, 6, 3, fmin, fmax);
sndr = SignalNoise(spec, d.Count, fs, f0, 0, 3, fmin, fmax);
enob = (sndr - 1.76) / 6.02;
}
