FourierForwardReal(Double, Int32, FourierOptions) Method

Packed Real-Complex forward Fast Fourier Transform (FFT) to arbitrary-length sample vectors. Since for real-valued time samples the complex spectrum is conjugate-even (symmetry), the spectrum can be fully reconstructed form the positive frequencies only (first half). The data array needs to be N+2 (if N is even) or N+1 (if N is odd) long in order to support such a packed spectrum.

public static void ForwardReal(
	double[] data,
	int n,
	FourierOptions options = FourierOptions.Default
)