public void SpectralAnalysis_RMSFromPowerSpectrum()
{
var sineGen = new SineWaveGenerator(1000, 100, 52100);
var d = sineGen.GetNextXSamples(1000).SelectMany(x => x.Data);
var data = d.ToList();
var fftData = SpectralAnaylser.FFT(data).ToArray();
var powerSpectrum = SpectralAnaylser.PowerSpectrum(fftData).ToArray();
var expected = Math.Sqrt(data.Select(x => x * x).Sum() / data.Count);
var rmsPowerSpec = SpectralAnaylser.RmsFromPowerSpec(powerSpectrum);
Assert.AreEqual(expected, rmsPowerSpec, 0.0001);
}
public void SpectralAnalysis_PowerSpectrum_FromComplexFFT()
{
var sineGen = new SineWaveGenerator(1000, 100, 52100);
var data = sineGen.GetNextXSamples(1000).SelectMany(x => x.Data);
var fftData = SpectralAnaylser.FFT(data).ToArray();
var powerSpectrum = SpectralAnaylser.PowerSpectrum(fftData).ToArray();
//First 20 points
var expectedData = new[]
{
0.245170056015,
0.49658325619,
0.515681392978,
0.548785216463,
0.597970475506,
0.66651053222,
0.759341701516,
0.883840416896,
1.05113644411,
1.2783980737,
1.59297851554,
2.04035148994,
2.70034243877,
3.7232172295,
5.41902088726,
8.51292503252,
15.0403276039,
32.666419917,
113.029844515,
4391.24421811
};
for (var i = 0; i < expectedData.Length; i++)
{
Assert.AreEqual(expectedData[i], powerSpectrum[i], 0.0001);
}
}
