dlib C++ Library - fft_stl.h

// Copyright (C) 2023 Davis E. King (davis@dlib.net)
// License: Boost Software License See LICENSE.txt for the full license.
#ifndef DLIB_FFT_STL_Hh_
#define DLIB_FFT_STL_Hh_
#include <vector>
#include "fft.h"
namespace dlib
{
// ----------------------------------------------------------------------------------------
 
 template < typename T, typename Alloc >
 void fft_inplace (std::vector<std::complex<T>, Alloc>& data)
 /*!
 requires
 - data contains elements of type std::complex<> that itself contains double, float, or long double.
 ensures
 - This function is identical to fft() except that it does the FFT in-place.
 That is, after this function executes we will have:
 - #data == fft(data)
 !*/
 {
 static_assert(std::is_floating_point<T>::value, "only support floating point types");
 if (data.size() != 0)
 fft({(long)data.size()}, &data[0], &data[0], false);
 }
// ----------------------------------------------------------------------------------------
 template < typename T, typename Alloc >
 void ifft_inplace (std::vector<std::complex<T>, Alloc>& data)
 /*!
 requires
 - data contains elements of type std::complex<> that itself contains double, float, or long double.
 ensures
 - This function is identical to ifft() except that it does the inverse FFT
 in-place. That is, after this function executes we will have:
 - #data == ifft(data)*data.size()
 - Note that the output needs to be divided by data.size() to complete the 
 inverse transformation. 
 !*/
 {
 static_assert(std::is_floating_point<T>::value, "only support floating point types");
 if (data.size() != 0)
 fft({(long)data.size()}, &data[0], &data[0], true);
 }
 
// ----------------------------------------------------------------------------------------
}
#endif //DLIB_FFT_STL_Hh_