/// <summary>
/// This method only called from Indexcalculate when returning image of the sonogram for the passed recording segment.
/// </summary>
public static double[] ConvertSpectralPeaksToNormalisedArray(double[,] spectrogram)
{
// convert spectral peaks to frequency and frames
var tupleDecibelPeaks = SpectrogramTools.HistogramOfSpectralPeaks(spectrogram);
// Item2 is length of Score Array and stores the bin in which the max peak is located.
// Normalise this for display in score track
return(DataTools.normalise(tupleDecibelPeaks.Item2));
}
} // CalculateSpectralEntropies()
/// <summary>
/// CALCULATES THE ENTROPY OF DISTRIBUTION of maximum SPECTRAL PEAKS.
/// Only spectral peaks between the lowerBinBound and the upperBinBound will be included in calculation.
/// </summary>
public static double CalculateEntropyOfSpectralPeaks(double[,] amplitudeSpectrogram, int lowerBinBound, int upperBinBound)
{
// First extract High band SPECTROGRAM which is now noise reduced
var midBandSpectrogram = MatrixTools.Submatrix(amplitudeSpectrogram, 0, lowerBinBound, amplitudeSpectrogram.GetLength(0) - 1, upperBinBound - 1);
var tupleAmplitudePeaks = SpectrogramTools.HistogramOfSpectralPeaks(midBandSpectrogram);
double entropyOfPeakFreqDistr = DataTools.EntropyNormalised(tupleAmplitudePeaks.Item1);
if (double.IsNaN(entropyOfPeakFreqDistr))
{
entropyOfPeakFreqDistr = 1.0;
}
return(entropyOfPeakFreqDistr);
} // CalculateEntropyOfSpectralPeaks()
/// <summary>
/// outputs an array of peak bins indices per frame
/// </summary>
public static int[] GetPeakBinsIndex(double[,] matrix, int minFreqBin, int maxFreqBin)
{
// get a submatrix with min and max frequency bins defined in settings.
double[,] targetMatrix = GetArbitraryFreqBandMatrix(matrix, minFreqBin, maxFreqBin);
// find the peak bins in each spectral of the target matrix
int[] peakBins = SpectrogramTools.HistogramOfSpectralPeaks(targetMatrix).Item2;
// map the index of peak bins in the target matrix to original input matrix
for (int i = 0; i < peakBins.Length; i++)
{
peakBins[i] = peakBins[i] + minFreqBin - 1;
}
return(peakBins);
}