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Indoor/lib/simple_fft/fft.h
2018-01-24 11:44:08 +01:00

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/*
* ----------------------------------------------------------------------------
* "THE BEER-WARE LICENSE" (Revision 42):
* Dmitry Ivanov <dm.vl.ivanov@gmail.com> wrote this file. As long as you retain
* this notice you can do whatever you want with this stuff. If we meet some day,
* and you think this stuff is worth it, you can buy me a beer in return.
* ----------------------------------------------------------------------------
*/
#ifndef __SIMPLE_FFT__FFT_H__
#define __SIMPLE_FFT__FFT_H__
#include <cstddef>
using std::size_t;
/// The public API
namespace simple_fft {
/// FFT and IFFT functions
// in-place, complex, forward
template <class TComplexArray1D>
bool FFT(TComplexArray1D & data, const size_t size, const char *& error_description);
template <class TComplexArray2D>
bool FFT(TComplexArray2D & data, const size_t size1, const size_t size2,
const char *& error_description);
template <class TComplexArray3D>
bool FFT(TComplexArray3D & data, const size_t size1, const size_t size2, const size_t size3,
const char *& error_description);
// in-place, complex, inverse
template <class TComplexArray1D>
bool IFFT(TComplexArray1D & data, const size_t size, const char *& error_description);
template <class TComplexArray2D>
bool IFFT(TComplexArray2D & data, const size_t size1, const size_t size2,
const char *& error_description);
template <class TComplexArray3D>
bool IFFT(TComplexArray3D & data, const size_t size1, const size_t size2, const size_t size3,
const char *& error_description);
// not-in-place, complex, forward
template <class TComplexArray1D>
bool FFT(const TComplexArray1D & data_in, TComplexArray1D & data_out,
const size_t size, const char *& error_description);
template <class TComplexArray2D>
bool FFT(const TComplexArray2D & data_in, TComplexArray2D & data_out,
const size_t size1, const size_t size2, const char *& error_description);
template <class TComplexArray3D>
bool FFT(const TComplexArray3D & data_in, TComplexArray3D & data_out,
const size_t size1, const size_t size2, const size_t size3,
const char *& error_description);
// not-in-place, complex, inverse
template <class TComplexArray1D>
bool IFFT(const TComplexArray1D & data_in, TComplexArray1D & data_out,
const size_t size, const char *& error_description);
template <class TComplexArray2D>
bool IFFT(const TComplexArray2D & data_in, TComplexArray2D & data_out,
const size_t size1, const size_t size2, const char *& error_description);
template <class TComplexArray3D>
bool IFFT(const TComplexArray3D & data_in, TComplexArray3D & data_out,
const size_t size1, const size_t size2, const size_t size3,
const char *& error_description);
// not-in-place, real, forward
template <class TRealArray1D, class TComplexArray1D>
bool FFT(const TRealArray1D & data_in, TComplexArray1D & data_out,
const size_t size, const char *& error_description);
template <class TRealArray2D, class TComplexArray2D>
bool FFT(const TRealArray2D & data_in, TComplexArray2D & data_out,
const size_t size1, const size_t size2, const char *& error_description);
template <class TRealArray3D, class TComplexArray3D>
bool FFT(const TRealArray3D & data_in, TComplexArray3D & data_out,
const size_t size1, const size_t size2, const size_t size3,
const char *& error_description);
// NOTE: There is no inverse transform from complex spectrum to real signal
// because round-off errors during computation of inverse FFT lead to the appearance
// of signal imaginary components even though they are small by absolute value.
// These can be ignored but the author of this file thinks adding such an function
// would be wrong methodogically: looking at complex result, you can estimate
// the value of spurious imaginary part. Otherwise you may never know that IFFT
// provides too large imaginary values due to too small grid size, for example.
} // namespace simple_fft
#endif // __SIMPLE_FFT__FFT_H__
#include "fft.hpp"