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dft_tools/triqs/gf/local/fourier_base.cpp
Laura Messio 38d89e2d01 work on gf: scalar_valued, ...
- introducing scalar_valued gf
- Change Fourier routines to run on scalar_valued,
and then use those routines to run on matrix_valued.
- Tools for slices of 2 variables functions
2013-07-19 13:41:34 +02:00

53 lines
2.2 KiB
C++

/*******************************************************************************
*
* TRIQS: a Toolbox for Research in Interacting Quantum Systems
*
* Copyright (C) 2011 by M. Ferrero, O. Parcollet
*
* TRIQS is free software: you can redistribute it and/or modify it under the
* terms of the GNU General Public License as published by the Free Software
* Foundation, either version 3 of the License, or (at your option) any later
* version.
*
* TRIQS is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License along with
* TRIQS. If not, see <http://www.gnu.org/licenses/>.
*
******************************************************************************/
#include "fourier_base.hpp"
#include <fftw3.h>
#include <algorithm>
namespace triqs { namespace gf { namespace details {
void fourier_base(const tqa::vector<dcomplex> &in, tqa::vector<dcomplex> &out, size_t L, bool direct) {
// !!!! L must always be the number of time bins !!!!
//const size_t L( (direct ? in.size() : out.size()) );
//const int L(max(in.size(),out.size())); <-- bug
fftw_complex *inFFT, *outFFT;
fftw_plan p;
inFFT = (fftw_complex*) fftw_malloc(sizeof(fftw_complex) * L);
outFFT = (fftw_complex*) fftw_malloc(sizeof(fftw_complex) * L);
const dcomplex * restrict in_ptr = in.data_start();
dcomplex * restrict out_ptr = out.data_start();
const size_t imax = std::min(L,in.size());
for (size_t i =0; i<imax; ++i) { inFFT[i][0] = real(in_ptr[i]); inFFT[i][1] = imag(in_ptr[i]);}
for (size_t i =imax; i<L; ++i) { inFFT[i][0] = 0; inFFT[i][1] = 0;}
// for (size_t i =0; i<L; ++i) { inFFT[i][0] = real(in_ptr[i]); inFFT[i][1] = imag(in_ptr[i]);}
p = fftw_plan_dft_1d(L, inFFT, outFFT, (direct ? FFTW_BACKWARD : FFTW_FORWARD), FFTW_ESTIMATE);
fftw_execute(p);
const size_t jmax = std::min(L,out.size());
for (size_t j =0; j<jmax; ++j) out_ptr[j] = dcomplex(outFFT[j][0] ,outFFT[j][1]);
fftw_destroy_plan(p);
fftw_free(inFFT); fftw_free(outFFT);
}
}}}