AnalysisSystemForRadionucli.../include/armadillo_bits/fn_fft2.hpp
2024-06-04 15:25:02 +08:00

125 lines
2.6 KiB
C++

// Copyright (C) 2013 National ICT Australia (NICTA)
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
// -------------------------------------------------------------------
//
// Written by Conrad Sanderson - http://conradsanderson.id.au
//! \addtogroup fn_fft2
//! @{
// 2D FFT & 2D IFFT
template<typename T1>
inline
typename
enable_if2
<
is_arma_type<T1>::value,
Mat< std::complex<typename T1::pod_type> >
>::result
fft2(const T1& A)
{
arma_extra_debug_sigprint();
// not exactly efficient, but "better-than-nothing" implementation
typedef typename T1::pod_type T;
Mat< std::complex<T> > B = fft(A);
// for square matrices, strans() will work out that an inplace transpose can be done,
// hence we can potentially avoid creating a temporary matrix
B = strans(B);
return strans( fft(B) );
}
template<typename T1>
inline
typename
enable_if2
<
is_arma_type<T1>::value,
Mat< std::complex<typename T1::pod_type> >
>::result
fft2(const T1& A, const uword n_rows, const uword n_cols)
{
arma_extra_debug_sigprint();
typedef typename T1::elem_type eT;
const unwrap<T1> tmp(A);
const Mat<eT>& B = tmp.M;
const bool do_resize = (B.n_rows != n_rows) || (B.n_cols != n_cols);
return fft2( do_resize ? resize(B,n_rows,n_cols) : B );
}
template<typename T1>
inline
typename
enable_if2
<
(is_arma_type<T1>::value && is_complex_strict<typename T1::elem_type>::value),
Mat< std::complex<typename T1::pod_type> >
>::result
ifft2(const T1& A)
{
arma_extra_debug_sigprint();
// not exactly efficient, but "better-than-nothing" implementation
typedef typename T1::pod_type T;
Mat< std::complex<T> > B = ifft(A);
// for square matrices, strans() will work out that an inplace transpose can be done,
// hence we can potentially avoid creating a temporary matrix
B = strans(B);
return strans( ifft(B) );
}
template<typename T1>
inline
typename
enable_if2
<
(is_arma_type<T1>::value && is_complex_strict<typename T1::elem_type>::value),
Mat< std::complex<typename T1::pod_type> >
>::result
ifft2(const T1& A, const uword n_rows, const uword n_cols)
{
arma_extra_debug_sigprint();
typedef typename T1::elem_type eT;
const unwrap<T1> tmp(A);
const Mat<eT>& B = tmp.M;
const bool do_resize = (B.n_rows != n_rows) || (B.n_cols != n_cols);
return ifft2( do_resize ? resize(B,n_rows,n_cols) : B );
}
//! @}