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