/*
* Free FFT and convolution (C++)
*
* Copyright (c) 2021 Project Nayuki. (MIT License)
* https://www.nayuki.io/page/free-small-fft-in-multiple-languages
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
* the Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
* - The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
* - The Software is provided "as is", without warranty of any kind, express or
* implied, including but not limited to the warranties of merchantability,
* fitness for a particular purpose and noninfringement. In no event shall the
* authors or copyright holders be liable for any claim, damages or other
* liability, whether in an action of contract, tort or otherwise, arising from,
* out of or in connection with the Software or the use or other dealings in the
* Software.
*/
#pragma once
#include
#include
namespace Fft {
/*
* Computes the discrete Fourier transform (DFT) of the given complex vector, storing the result back into the vector.
* The vector can have any length. This is a wrapper function.
*/
void transform(std::vector &real, std::vector &imag);
/*
* Computes the inverse discrete Fourier transform (IDFT) of the given complex vector, storing the result back into the vector.
* The vector can have any length. This is a wrapper function. This transform does not perform scaling, so the inverse is not a true inverse.
*/
void inverseTransform(std::vector &real, std::vector &imag);
/*
* Computes the discrete Fourier transform (DFT) of the given complex vector, storing the result back into the vector.
* The vector's length must be a power of 2. Uses the Cooley-Tukey decimation-in-time radix-2 algorithm.
*/
void transformRadix2(std::vector &real, std::vector &imag);
/*
* Computes the discrete Fourier transform (DFT) of the given complex vector, storing the result back into the vector.
* The vector can have any length. This requires the convolution function, which in turn requires the radix-2 FFT function.
* Uses Bluestein's chirp z-transform algorithm.
*/
void transformBluestein(std::vector &real, std::vector &imag);
/*
* Computes the circular convolution of the given real vectors. Each vector's length must be the same.
*/
std::vector convolve(std::vector xvec, std::vector yvec);
/*
* Computes the circular convolution of the given complex vectors. Each vector's length must be the same.
*/
std::pair, std::vector > convolve(
std::vector xreal, std::vector ximag,
std::vector yreal, std::vector yimag);
}