common/alcomplex.h

   1 #ifndef ALCOMPLEX_H
   2 #define ALCOMPLEX_H
   3
   4 #include <complex>
   5
   6 #include "alspan.h"
   7
   8 /**
   9  * Iterative implementation of 2-radix FFT (In-place algorithm). Sign = -1 is
  10  * FFT and 1 is iFFT (inverse). Fills the buffer with the Discrete Fourier
  11  * Transform (DFT) of the time domain data stored in the buffer. The buffer is
  12  * an array of complex numbers, and MUST BE power of two.
  13  */
  14 void complex_fft(const al::span<std::complex<double>> buffer, const double sign);
  15
  16 /**
  17  * Calculate the complex helical sequence (discrete-time analytical signal) of
  18  * the given input using the discrete Hilbert transform (In-place algorithm).
  19  * Fills the buffer with the discrete-time analytical signal stored in the
  20  * buffer. The buffer is an array of complex numbers and MUST BE power of two,
  21  * and the imaginary components should be cleared to 0.
  22  */
  23 void complex_hilbert(const al::span<std::complex<double>> buffer);
  24
  25 #endif /* ALCOMPLEX_H */