public Spectrum GetSpectrum(ISignal signal)
{
var specArr = transformer.Transform(signal.GetValues().ToArray());
var len = (double)specArr.Length;
var dur = signal.GetDurationInSeconds();
var points = specArr
.Select((val, idx) => new FreqPoint(val, len / idx * dur))
.ToArray();
return(new Spectrum(new SpectrumLine[] { new SpectrumLine(points, 0) }));
}