|
#ifndef ALCOMPLEX_H
|
|
#define ALCOMPLEX_H
|
|
|
|
#include <complex>
|
|
|
|
#include "alspan.h"
|
|
|
|
/**
|
|
* Iterative implementation of 2-radix FFT (In-place algorithm). Sign = -1 is
|
|
* FFT and 1 is inverse FFT. Applies the Discrete Fourier Transform (DFT) to
|
|
* the data supplied in the buffer, which MUST BE power of two.
|
|
*/
|
|
void complex_fft(const al::span<std::complex<double>> buffer, const double sign);
|
|
|
|
/**
|
|
* Calculate the frequency-domain response of the time-domain signal in the
|
|
* provided buffer, which MUST BE power of two.
|
|
*/
|
|
inline void forward_fft(const al::span<std::complex<double>> buffer)
|
|
{ complex_fft(buffer, -1.0); }
|
|
|
|
/**
|
|
* Calculate the time-domain signal of the frequency-domain response in the
|
|
* provided buffer, which MUST BE power of two.
|
|
*/
|
|
inline void inverse_fft(const al::span<std::complex<double>> buffer)
|
|
{ complex_fft(buffer, 1.0); }
|
|
|
|
/**
|
|
* Calculate the complex helical sequence (discrete-time analytical signal) of
|
|
* the given input using the discrete Hilbert transform (In-place algorithm).
|
|
* Fills the buffer with the discrete-time analytical signal stored in the
|
|
* buffer. The buffer is an array of complex numbers and MUST BE power of two,
|
|
* and the imaginary components should be cleared to 0.
|
|
*/
|
|
void complex_hilbert(const al::span<std::complex<double>> buffer);
|
|
|
|
#endif /* ALCOMPLEX_H */
|