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dft_tools/triqs/gfs/local/legendre_matsubara.cpp
Olivier Parcollet 579368f24b gf. Clean Fourier
- lazy_fourier and co --> fourier
- ex fourier --> make_gf_from_fourier to make a new gf
- = fourier (g) works only iif lhs is a view, like scalar.
- updated python (commented fourier method).
2013-10-23 18:46:55 +02:00

115 lines
3.5 KiB
C++

/*******************************************************************************
*
* TRIQS: a Toolbox for Research in Interacting Quantum Systems
*
* Copyright (C) 2011-2014 by L. Boehnke, 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 "legendre_matsubara.hpp"
#include "fourier_matsubara.hpp"
#include "functions.hpp"
#include <triqs/utility/legendre.hpp>
using namespace triqs::utility;
namespace triqs {
namespace gfs {
// ----------------------------
void legendre_matsubara_direct(gf_view<imfreq> gw, gf_const_view<legendre> gl) {
gw() = 0.0;
triqs::arrays::range R;
// Use the transformation matrix
for (auto om : gw.mesh()) {
for (auto l : gl.mesh()) {
gw[om] += legendre_T(om.index(), l.index()) * gl[l];
}
}
gw.singularity() = get_tail(gl, gw.singularity().size(), gw.singularity().order_min());
}
// ----------------------------
void legendre_matsubara_direct(gf_view<imtime> gt, gf_const_view<legendre> gl) {
gt() = 0.0;
legendre_generator L;
for (auto t : gt.mesh()) {
L.reset(2 * t / gt.domain().beta - 1);
for (auto l : gl.mesh()) {
gt[t] += sqrt(2 * l.index() + 1) / gt.domain().beta * gl[l] * L.next();
}
}
gt.singularity() = get_tail(gl, gt.singularity().size(), gt.singularity().order_min());
}
// ----------------------------
void legendre_matsubara_inverse(gf_view<legendre> gl, gf_const_view<imtime> gt) {
gl() = 0.0;
legendre_generator L;
// Do the integral over imaginary time
for (auto t : gt.mesh()) {
L.reset(2 * t / gt.domain().beta - 1);
for (auto l : gl.mesh()) {
gl[l] += sqrt(2 * l.index() + 1) * L.next() * gt[t];
}
}
gl.data() *= gt.mesh().delta();
}
// ----------------------------
void legendre_matsubara_inverse(gf_view<legendre> gl, gf_const_view<imfreq> gw) {
gl() = 0.0;
// Construct a temporary imaginary-time Green's function gt
// I set Nt time bins. This is ugly, one day we must code the direct
// transformation without going through imaginary time
int Nt = 50000;
auto gt = gf<imtime>{{gw.domain(), Nt, half_bins}, gw.data().shape().front_pop()};
// We first transform to imaginary time because it's been coded with the knowledge of the tails
gt() = inverse_fourier(gw);
legendre_matsubara_inverse(gl, gt());
}
void triqs_gf_view_assign_delegation(gf_view<imfreq> gw, gf_keeper<tags::legendre, legendre> const& L) {
legendre_matsubara_direct(gw, L.g);
}
void triqs_gf_view_assign_delegation(gf_view<imtime> gt, gf_keeper<tags::legendre, legendre> const& L) {
legendre_matsubara_direct(gt, L.g);
}
void triqs_gf_view_assign_delegation(gf_view<legendre> gl, gf_keeper<tags::legendre, imfreq> const& L) {
legendre_matsubara_inverse(gl, L.g);
}
void triqs_gf_view_assign_delegation(gf_view<legendre> gl, gf_keeper<tags::legendre, imtime> const& L) {
legendre_matsubara_inverse(gl, L.g);
}
}
}