public void Complex_Symmetry_RealEven_RealEven()
{
// h(t) real-valued even <=> H(f) real-valued even-with-offset
int numSamples = 32;
int length = 2 * numSamples;
double[] data = new double[length];
for (int i = 0; i < length; i += 2)
{
double z = (double)(i - numSamples) / numSamples;
data[i] = 1.0 / (z * z + 1.0);
data[i + 1] = 0.0;
}
ComplexTestTimeEven(data);
cft.Convention = TransformationConvention.Matlab; // so we can check MATLAB consistency
cft.TransformForward(data);
ComplexTestImagZero(data);
ComplexTestFreqEven(data);
/* Compare With MATLAB:
* samples_t = 1.0 ./ (([-16:1:15] ./ 16) .^ 2 + 1.0)
* samples_f = fft(samples_t)
*/
Assert.AreEqual(25.128, data[0 * 2], 0.001, "MATLAB 1");
Assert.AreEqual(-3.623, data[1 * 2], 0.001, "MATLAB 2");
Assert.AreEqual(-0.31055, data[2 * 2], 0.00001, "MATLAB 3");
Assert.AreEqual(-0.050611, data[6 * 2], 0.000001, "MATLAB 7");
Assert.AreEqual(-0.03882, data[7 * 2], 0.00001, "MATLAB 8");
Assert.AreEqual(-0.031248, data[8 * 2], 0.000001, "MATLAB 9");
Assert.AreEqual(-0.017063, data[13 * 2], 0.000001, "MATLAB 14");
Assert.AreEqual(-0.016243, data[14 * 2], 0.000001, "MATLAB 15");
Assert.AreEqual(-0.015777, data[15 * 2], 0.000001, "MATLAB 16");
}
public static void FFT(Complex[] xdata)
{
Debug.WriteLine("FFT data:" + xdata.Length);
cft.TransformForward(xdata);
}