public ActionResult <FrequencyDomain> FFT([FromBody] List <Double> value)
{
ComplexFastFourierTransform fft = new ComplexFastFourierTransform();
FrequencyDomain transform = fft.Transform(value);
return(Ok(transform));
}
public IList <Complex> FrequencyResponse()
{
ComplexFastFourierTransform transform = new ComplexFastFourierTransform();
List <Complex> coefficients = transform.Transform(new List <double>(ImpulseResponse()), FilterLength).FourierCoefficients;
return(coefficients);
}
private void ExportButton_Click(object sender, RoutedEventArgs e)
{
SaveFileDialog saveFileDialog = new SaveFileDialog();
saveFileDialog.Filter = $"{Properties.Resources.FILTER_IMPORT_EXPORT_FILE_EXTENSION} (*{Properties.Resources.FILTER_IMPORT_EXPORT_FILE_EXTENSION})|*{Properties.Resources.FILTER_IMPORT_EXPORT_FILE_EXTENSION}|{Properties.Resources.ALL_FILES} (*.*)|*.*";
if (saveFileDialog.ShowDialog() == true)
{
try
{
using (StreamWriter fileWriter = File.CreateText(saveFileDialog.FileName))
{
fileWriter.WriteLine(Properties.Resources.FILTER_CSV_HEADER);
List <double> summedFilterData = manager.ActiveWorkBook().CombinedFilterImpulseResponse(true);
ComplexFastFourierTransform cmplxFFT = new ComplexFastFourierTransform();
FrequencyDomain frequencyDomain = cmplxFFT.Transform(summedFilterData, manager.ActiveWorkBook().WindowedSyncFilters.Values.First().FilterLength);
var magPhaseList = ComplexFastFourierTransform.ToMagnitudePhaseList(frequencyDomain);
foreach (Tuple <double, double> coefficientMagPhase in magPhaseList)
{
fileWriter.WriteLine($"{coefficientMagPhase.Item1},{coefficientMagPhase.Item2}");
}
}
} catch (Exception ex)
{
Log.Warning(ex, ex.Message);
// TODO warn user
}
}
}
public void TestLoadFromFrequencyAmplitudes()
{
// low pass amplitude array
double[] amplitudes = { 1.0, 1.0, 1.0, 1.0, 1.0, 1.0,
1.0, 1.0, 1.0, 1.0, 1.0, 1.0,
0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
0.0, 0.0 };
List <double> frequencyDomain = new List <double>(amplitudes);
//FrequencyDomain frequencyDomain = ComplexFastFourierTransform.LoadFourierCoefficients(new List<double>(amplitudes));
ComplexFastFourierTransform synth = new ComplexFastFourierTransform();
FrequencyDomain timeDomain = synth.Transform(frequencyDomain, 2 * frequencyDomain.Count());
foreach (var value in timeDomain.FrequencyAmplitudes)
{
Console.WriteLine(value);
}
}
// 64 channel sample with padCount zeros padded right
public List <double> GetPaddedChannelSample(int sampleCount, int padCount)
{
int numSamplesToGet = (sampleCount - padCount);
int curIDX = _sampleIDX;
if (curIDX + numSamplesToGet >= _samples.Count)
{
numSamplesToGet = _samples.Count - curIDX;
if (numSamplesToGet <= 0)
{
// Roll over to the beginning
_sampleIDX = 0;
return(GetPaddedChannelSample(sampleCount, padCount));
}
}
_sampleIDX += numSamplesToGet;
_sliceSignal = _samples.GetRange(curIDX, numSamplesToGet);
List <double> paddedSignal = new List <double>(sampleCount);
paddedSignal.AddRange(_sliceSignal);
// Pad
int padLen = (sampleCount - numSamplesToGet);
for (int cnt = 0; cnt < padLen; cnt++)
{
paddedSignal.Add(0.0);
}
IDFT ff_transform = new ComplexFastFourierTransform();
IDFT cdf_tranform = new CorrelationFourierTransform();
//_frequencyDomain = DFT.CorrelationTransform(paddedSignal);
_frequencyDomain = ff_transform.Transform(paddedSignal);
return(_sliceSignal);
}