private static void TestFft()
{
Fft transformer = new Fft();
ICollection<Complex> transformed = transformer.DoTransform(f, N);
Console.WriteLine("Fast Fourier Transform\n");
Print(transformed);
}
private void PopulateSeriesData()
{
FourierTransform discreteTransform = new Dft();
FourierTransform fastTransform = new Fft();
FastWalshTransform walshTransform = new FastWalshTransform();
Discretizer discretizer = new Discretizer();
LineSeriesBuilder seriesBuilder = new LineSeriesBuilder();
IDictionary<double, double> discreteData = discretizer.Discretize(f, 0, Period, Period/N)
.Take(N) // Take only the given number of elements. Otherwise problem appears in FFT.
.ToDictionary(x => x.Key, x => x.Value);
double[] fwtData = walshTransform.DoTransform(discreteData.Values.ToArray());
ICollection<Complex> discreteTransformData = discreteTransform.DoTransform(discreteData.Values);
ICollection<Complex> fastTransformData = fastTransform.DoTransform(discreteData.Values);
seriesManager.Add(SeriesNames.DftMagnitudes, seriesBuilder.CreateSeries("DFT Magnitude", discreteData.Keys, discreteTransform.Magnitudes));
seriesManager.Add(SeriesNames.FftMagnitudes, seriesBuilder.CreateSeries("FFT Magnitude", discreteData.Keys, fastTransform.Magnitudes));
seriesManager.Add(SeriesNames.DftPhases, seriesBuilder.CreateSeries("DFT Phase", discreteData.Keys, discreteTransform.Phases));
seriesManager.Add(SeriesNames.FftPhases, seriesBuilder.CreateSeries("FFT Phase", discreteData.Keys, fastTransform.Phases));
seriesManager.Add(SeriesNames.ForwardFwt, seriesBuilder.CreateSeries("FWT", discreteData.Keys, fwtData));
double[] fwtDataInverse = walshTransform.DoTransformInverse(fwtData);
seriesManager.Add(SeriesNames.InverseFwt, seriesBuilder.CreateSeries("IFWT", discreteData.Keys, fwtDataInverse));
PopulateStats();
discreteTransform.DoTransformInverse(discreteTransformData);
fastTransform.DoTransformInverse(fastTransformData);
seriesManager.Add(SeriesNames.OriginalF, seriesBuilder.CreateSeries("Original F(x)", discretizer.Discretize(f, 0, Period, 0.01)));
seriesManager.Add(SeriesNames.InverseFft, seriesBuilder.CreateSeries("Inverse FFT", discreteData.Keys, fastTransform.Magnitudes));
seriesManager.Add(SeriesNames.InverseDft, seriesBuilder.CreateSeries("Inverse DFT", discreteData.Keys, discreteTransform.Magnitudes));
}