private Harmonic GetHarmonicAmplitudeAndPhase(double [] funcValues, int harmonicNumber)
{
double re = 0;
double im = 0;
int sinIndex = 0;
int cosIndex = cosOffset;
for (int i = 0; i < samplingFrequency; i++)
{
re += funcValues[i] * sinArray[cosIndex];
im += funcValues[i] * sinArray[sinIndex];
sinIndex = (sinIndex + harmonicNumber) % samplingFrequency;
cosIndex = (cosIndex + harmonicNumber) % samplingFrequency;
}
double amplitudeCos = 2 * re / samplingFrequency;
double amplitudeSin = 2 * im / samplingFrequency;
double amplitude = Math.Sqrt(Math.Pow(amplitudeCos, 2) + Math.Pow(amplitudeSin, 2));
double phase = Math.Atan2(amplitudeSin, amplitudeCos);
amplitude = Math.Round(amplitude, DigitsAfterDot);
phase = Math.Round(phase, DigitsAfterDot);
Harmonic result = new Harmonic(harmonicNumber, amplitude, phase);
return(result);
}
/// <summary>
/// Get Amplitude Frequency and Phase Frequency response.
/// </summary>
/// <param name="funcValues">Array of values from what should be Amplitude and Phase spectrums created.</param>
/// <param name="countOfHarmonics">The number of harmonics into which <paramref name="funcValues"/> should be divided.</param>
/// <returns>Array of <see cref="Harmonic"/> where each element contains Amplitude and Phase of a harmonic.</returns>
/// <exception cref="ArgumentException">if the length of <see cref="funcValues"/> is not equal to Sampling Frequency.</exception>
public Harmonic[] GetFrequencyResponse(double[] funcValues, int countOfHarmonics /*, FrequencyResponse responseType*/)
{
if (funcValues.Length < samplingFrequency)
{
throw new ArgumentException(nameof(funcValues),
$"Size of the array should be equal or greater than {samplingFrequency}");
}
Harmonic[] result = new Harmonic[countOfHarmonics];
for (int i = 0; i < countOfHarmonics; i++)
{
result[i] = GetHarmonicAmplitudeAndPhase(funcValues, i);
}
return(result);
}
private Harmonic[] ParseComplex(Complex[] array)
{
int halfFrequencyArray = array.Length / 2;
Harmonic[] result = new Harmonic[halfFrequencyArray];
double amplitude = array[0].Magnitude / samplingFrequency;
double phase = 0;
result[0] = new Harmonic(0, amplitude, phase);
for (int i = 0; i < halfFrequencyArray; i++)
{
amplitude = Math.Round(array[i].Magnitude / halfSamplingFrequency, DigitsAfterDot);
phase = Math.Round(Math.Atan2(array[i].Imaginary, array[i].Real), DigitsAfterDot);
result[i] = new Harmonic(i, amplitude, phase);
}
return(result);
}
