public static void TestMethod_GenerateSignal2()
{
int sampleRate = 64000;
double duration = 30; // signal duration in seconds
int[] harmonics = { 500, 1000, 2000, 4000, 8000 };
var freqScale = new FrequencyScale(FreqScaleType.Linear125Octaves7Tones28Nyquist32000);
string path = @"C:\SensorNetworks\Output\Sonograms\UnitTestSonograms\SineSignal2.png";
var recording = GenerateTestRecording(sampleRate, duration, harmonics, WaveType.Cosine);
// init the default sonogram config
var sonoConfig = new SonogramConfig
{
WindowSize = freqScale.WindowSize,
WindowOverlap = 0.2,
SourceFName = "Signal2",
NoiseReductionType = NoiseReductionType.None,
NoiseReductionParameter = 0.0,
};
var sonogram = new AmplitudeSonogram(sonoConfig, recording.WavReader);
sonogram.Data = OctaveFreqScale.ConvertAmplitudeSpectrogramToDecibelOctaveScale(sonogram.Data, freqScale);
// pick a row, any row
var oneSpectrum = MatrixTools.GetRow(sonogram.Data, 40);
oneSpectrum = DataTools.normalise(oneSpectrum);
var peaks = DataTools.GetPeaks(oneSpectrum, 0.5);
var peakIds = new List <int>();
for (int i = 5; i < peaks.Length - 5; i++)
{
if (peaks[i])
{
int peakId = freqScale.BinBounds[i, 0];
peakIds.Add(peakId);
LoggedConsole.WriteLine($"Spectral peak located in bin {peakId}, Herz={freqScale.BinBounds[i, 1]}");
}
}
//if (peaks[129] && peaks[257] && peaks[513] && peaks[1025] && peaks[2049])
if (peakIds[0] == 129 && peakIds[1] == 257 && peakIds[2] == 513 && peakIds[3] == 1025 && peakIds[4] == 2049)
{
LoggedConsole.WriteSuccessLine("Spectral Peaks found at correct places");
}
else
{
LoggedConsole.WriteErrorLine("Spectral Peaks found at INCORRECT places");
}
foreach (int h in harmonics)
{
LoggedConsole.WriteLine($"Harmonic {h}Hertz should be in bin {freqScale.GetBinIdForHerzValue(h)}");
}
// spectrogram without framing, annotation etc
var image = sonogram.GetImage();
string title = $"Spectrogram of Harmonics: {DataTools.Array2String(harmonics)} SR={sampleRate} Window={freqScale.WindowSize}";
image = sonogram.GetImageFullyAnnotated(image, title, freqScale.GridLineLocations);
image.Save(path);
}