//this method calculates the degree of membership for a particular value
public override double CalculateDOM(double val)
{
//test for the case where the triangle's left or right offsets are zero
//(to prevent divide by zero errors below)
if (RightOffset.Equals(0.0) && PeakPoint.Equals(val) ||
LeftOffset.Equals(0.0) && PeakPoint.Equals(val))
{
return(1.0);
}
//find DOM if left of center
if ((val <= PeakPoint) && (val >= (PeakPoint - LeftOffset)))
{
double grad = 1.0 / LeftOffset;
return(grad * (val - (PeakPoint - LeftOffset)));
}
//find DOM if right of center
if (val > PeakPoint && (val < (PeakPoint + RightOffset)))
{
double grad = 1.0 / -RightOffset;
return(grad * (val - PeakPoint) + 1.0);
}
//out of range of this FLV, return zero
return(0.0);
}
protected IDataPoints InitSpectrum(ISpectrum spectrum)
{
BucketSpectrumDataPoints data = new BucketSpectrumDataPoints(
(parameter as DPSpectrumCIDParameter).GetBucketSize(),
(parameter as DPSpectrumCIDParameter).GetMinRange());
int charge = (spectrum as ISpectrumMSn).GetParentCharge();
for (int i = 1; i <= charge; i++)
{
foreach (IPeak peak in spectrum.GetPeaks())
{
PeakPoint pt = new PeakPoint(peak.GetIntensity(), peak.GetMZ(), i, peak.GetMZ().ToString());
data.Add(pt);
}
}
return(data);
}
public override double CalculateDOM(double val)
{
//check for case where the offset may be zero
if (RightOffset == 0 && val.Equals(PeakPoint) || LeftOffset == 0.0 && (PeakPoint.Equals(val)))
{
return(1.0);
}
//find DOM if left of center
if ((val <= PeakPoint) && (val > (PeakPoint - LeftOffset)))
{
double grad = 1.0 / LeftOffset;
return(grad * (val - (PeakPoint - LeftOffset)));
}
//find DOM if right of center
if (val > PeakPoint && (val <= PeakPoint + RightOffset))
{
return(1.0);
}
//out of range of this FLV, return zero
else
{
return(0.0);
}
}
public static double?EstimateBasicFrequency(int sampleRate, float[] samples, int PowerAverageValue) //ReadOnlySpan<float>
{
// SDF
// 1. zero pad
var sdf = new Complex[samples.Length * 2];
for (var i = 0; i < samples.Length; i++)
{
sdf[i] = samples[i];
}
// 2. FFT
FourierTransform2.FFT(sdf, FourierTransform.Direction.Forward);
// 3. パワースペクトル
bool isPower = false;
double total = 0f;
for (var i = 0; i < sdf.Length; i++)
{
var x = sdf[i];
sdf[i] = x.Real * x.Real + x.Imaginary * x.Imaginary;
total += sdf[i].Magnitude;
}
//デシベル変換(パワー平均値を求める)
dB = (int)(20 * Math.Log10(total / sampleRate));
//UnityEngine.Assertions.Assert.IsTrue(dB > 100, dB.ToString() + " dB");
if (dB > PowerAverageValue)
{
isPower = true;
}
//デシベルを下回ったら
if (!isPower)
{
return(null);
}
// 4. inverse FFT
FourierTransform2.FFT(sdf, FourierTransform.Direction.Backward);
// NSDF
var nsdf = new double[samples.Length];
var m = 0.0;
for (var i = 0; i < samples.Length; i++)
{
var x = (double)samples[i];
m += x * x;
var inv = samples.Length - i - 1;
x = samples[inv];
m += x * x;
nsdf[inv] = 2.0 * sdf[inv].Real / m;
}
// ピーク検出
var maxCorrelation = 0.0;
var peaks = new List <PeakPoint>();
for (var i = 1; i < samples.Length; i++)
{
if (nsdf[i] > 0 && nsdf[i - 1] <= 0)
{
var currentMax = new PeakPoint(i, nsdf[i]);
i++;
for (; i < samples.Length; i++)
{
if (nsdf[i] > currentMax.Correlation)
{
currentMax.Delay = i;
currentMax.Correlation = nsdf[i];
}
else if (nsdf[i] < 0)
{
// 0 未満になったので一山終了
break;
}
}
peaks.Add(currentMax);
if (currentMax.Correlation > maxCorrelation)
{
maxCorrelation = currentMax.Correlation;
}
}
}
if (peaks.Count == 0)
{
return(null); // 推定失敗
}
var threshold = maxCorrelation * 0.8;
var mainPeak = peaks.Find(x => x.Correlation >= threshold);
var delay = mainPeak.Delay == nsdf.Length - 1
? mainPeak.Delay
: GetTopX(
mainPeak.Delay - 1, nsdf[mainPeak.Delay - 1],
mainPeak.Delay, mainPeak.Correlation,
mainPeak.Delay + 1, nsdf[mainPeak.Delay + 1]
);
Accord.Diagnostics.Debug.Assert(delay >= mainPeak.Delay - 1 && delay <= mainPeak.Delay + 1);
return(sampleRate / delay);
}
