public float[] CreateScalogram(float sinusoidFrequency, float cycles)
{
var signalFFT = new FastFourierTransformCPU(AudioContainer.Samples).CreateTransformZeroPadded();
var sigma = 6;
return(CreateScalogram(sinusoidFrequency, signalFFT, AudioContainer.SampleRate, cycles, sigma));
}
public static float[] CreateScalogram(float frequency, Complex[] signalFT, int sampleRate, float cyclesCount, double sigma)
{
var pointsCount = signalFT.Length;
var wavelet = GenerateMorletWavelet(frequency, sampleRate, cyclesCount, pointsCount, sigma);
var kernelFFT = new FastFourierTransformCPU(wavelet).CreateTransformZeroPadded();
var pointwiseMultiplication = new Complex[pointsCount];
for (int i = 0; i < pointsCount; i++)
{
pointwiseMultiplication[i] = signalFT[i] * kernelFFT[i];
}
var inverseFFT = new FastFourierTransformCPU(pointwiseMultiplication).CreateTransform(false);
var amplitudes = new float[inverseFFT.Length];
for (int i = 0; i < amplitudes.Length; i++)
{
//amplitudes[i] = (float)inverseFFT[i].Imaginary;
var value = inverseFFT[i];
//amplitudes[i] = (float)Math.Sqrt(value.Real * value.Real + value.Imaginary * value.Imaginary);
//amplitudes[i] = (float)value.Real;
amplitudes[i] = (float)value.Magnitude;
//amplitudes[i] = (float)value.Imaginary;
}
return(amplitudes);
}