mirror of
https://github.com/triqs/dft_tools
synced 2024-11-01 03:33:50 +01:00
151 lines
6.0 KiB
C++
151 lines
6.0 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_real.hpp"
|
|
#include <fftw3.h>
|
|
|
|
namespace triqs { namespace gfs {
|
|
|
|
namespace {
|
|
double pi = std::acos(-1);
|
|
dcomplex I(0,1);
|
|
inline dcomplex th_expo(double t, double a ) { return (t > 0 ? -I * exp(-a*t) : ( t < 0 ? 0 : -0.5 * I * exp(-a*t) ) ) ; }
|
|
inline dcomplex th_expo_neg(double t, double a ) { return (t < 0 ? I * exp( a*t) : ( t > 0 ? 0 : 0.5 * I * exp( a*t) ) ) ; }
|
|
inline dcomplex th_expo_inv(double w, double a ) { return 1./(w+I*a) ; }
|
|
inline dcomplex th_expo_neg_inv(double w, double a ) { return 1./(w-I*a) ; }
|
|
}
|
|
|
|
struct impl_worker {
|
|
|
|
tqa::vector<dcomplex> g_in, g_out;
|
|
|
|
void direct (gf_view<refreq,scalar_valued> gw, gf_const_view<retime,scalar_valued> gt){
|
|
|
|
size_t L = gt.mesh().size();
|
|
if (gw.mesh().size() != L) TRIQS_RUNTIME_ERROR << "Meshes are different";
|
|
double test = std::abs(gt.mesh().delta() * gw.mesh().delta() * L / (2*pi) -1);
|
|
if (test > 1.e-10) TRIQS_RUNTIME_ERROR << "Meshes are not compatible";
|
|
|
|
const double tmin = gt.mesh().x_min();
|
|
const double wmin = gw.mesh().x_min();
|
|
//a is a number very larger than delta_w and very smaller than wmax-wmin, used in the tail computation
|
|
const double a = gw.mesh().delta() * sqrt( double(L) );
|
|
|
|
auto ta = gt(freq_infty());
|
|
g_in.resize(L);
|
|
g_in() = 0;
|
|
g_out.resize(L);
|
|
|
|
dcomplex t1 = ta(1)(0,0), t2= ta.get_or_zero(2)(0,0);
|
|
dcomplex a1 = (t1 + I * t2/a )/2., a2 = (t1 - I * t2/a )/2.;
|
|
|
|
for (auto const & t : gt.mesh())
|
|
g_in[t.index()] = (gt[t] - (a1*th_expo(t,a) + a2*th_expo_neg(t,a))) * std::exp(I*t*wmin);
|
|
|
|
details::fourier_base(g_in, g_out, L, true);
|
|
|
|
for (auto const & w : gw.mesh())
|
|
gw[w] = gt.mesh().delta() * std::exp(I*(w-wmin)*tmin) * g_out(w.index())
|
|
+ a1*th_expo_inv(w,a) + a2*th_expo_neg_inv(w,a);
|
|
|
|
gw.singularity() = gt.singularity();// set tail
|
|
|
|
}
|
|
|
|
void inverse(gf_view<retime,scalar_valued> gt, gf_const_view<refreq,scalar_valued> gw){
|
|
|
|
size_t L = gw.mesh().size();
|
|
if ( L != gt.mesh().size()) TRIQS_RUNTIME_ERROR << "Meshes are different";
|
|
double test = std::abs(gt.mesh().delta() * gw.mesh().delta() * L / (2*pi) -1);
|
|
if (test > 1.e-10) TRIQS_RUNTIME_ERROR << "Meshes are not compatible";
|
|
|
|
const double tmin = gt.mesh().x_min();
|
|
const double wmin = gw.mesh().x_min();
|
|
//a is a number very larger than delta_w and very smaller than wmax-wmin, used in the tail computation
|
|
const double a = gw.mesh().delta() * sqrt( double(L) );
|
|
|
|
auto ta = gw(freq_infty());
|
|
tqa::vector<dcomplex> g_in(L), g_out(L);
|
|
|
|
dcomplex t1 = ta(1)(0,0), t2 = ta.get_or_zero(2)(0,0);
|
|
dcomplex a1 = (t1 + I * t2/a )/2., a2 = (t1 - I * t2/a )/2.;
|
|
g_in() = 0;
|
|
|
|
for (auto const & w: gw.mesh())
|
|
g_in(w.index()) = (gw[w] - a1*th_expo_inv(w,a) - a2*th_expo_neg_inv(w,a) ) * std::exp(-I*w*tmin);
|
|
|
|
details::fourier_base(g_in, g_out, L, false);
|
|
|
|
const double corr = 1.0/(gt.mesh().delta()*L);
|
|
for (auto const & t : gt.mesh())
|
|
gt[t] = corr * std::exp(I*wmin*(tmin-t)) *
|
|
g_out[ t.index() ] + a1 * th_expo(t,a) + a2 * th_expo_neg(t,a) ;
|
|
|
|
// set tail
|
|
gt.singularity() = gw.singularity();
|
|
}
|
|
|
|
};
|
|
|
|
|
|
//--------------------------------------------------------------------------------------
|
|
|
|
void fourier_impl(gf_view<refreq,scalar_valued> gw, gf_const_view<retime,scalar_valued> gt, scalar_valued){
|
|
impl_worker w;
|
|
w.direct(gw, gt);
|
|
}
|
|
|
|
void fourier_impl(gf_view<refreq,matrix_valued> gw, gf_const_view<retime,matrix_valued> gt, matrix_valued){
|
|
impl_worker w;
|
|
for (size_t n1=0; n1<gw.data().shape()[1];n1++)
|
|
for (size_t n2=0; n2<gw.data().shape()[2];n2++) {
|
|
auto gw_sl=slice_target_to_scalar(gw, n1, n2);
|
|
auto gt_sl=slice_target_to_scalar(gt, n1, n2);
|
|
w.direct(gw_sl, gt_sl);
|
|
}
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
|
|
void inverse_fourier_impl (gf_view<retime,scalar_valued> gt, gf_const_view<refreq,scalar_valued> gw, scalar_valued){
|
|
impl_worker w;
|
|
w.inverse(gt,gw);
|
|
}
|
|
|
|
void inverse_fourier_impl (gf_view<retime,matrix_valued> gt, gf_const_view<refreq,matrix_valued> gw, matrix_valued){
|
|
impl_worker w;
|
|
for (size_t n1=0; n1<gt.data().shape()[1];n1++)
|
|
for (size_t n2=0; n2<gt.data().shape()[2];n2++) {
|
|
auto gt_sl=slice_target_to_scalar(gt, n1, n2);
|
|
auto gw_sl=slice_target_to_scalar(gw, n1, n2);
|
|
w.inverse(gt_sl, gw_sl);
|
|
}
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
|
|
void triqs_gf_view_assign_delegation( gf_view<refreq,matrix_valued> g, gf_keeper<tags::fourier,retime,matrix_valued> const & L) { fourier_impl (g,L.g, matrix_valued());}
|
|
void triqs_gf_view_assign_delegation( gf_view<refreq,scalar_valued> g, gf_keeper<tags::fourier,retime,scalar_valued> const & L) { fourier_impl (g,L.g, scalar_valued());}
|
|
void triqs_gf_view_assign_delegation( gf_view<retime,matrix_valued> g, gf_keeper<tags::fourier,refreq,matrix_valued> const & L) { inverse_fourier_impl(g,L.g, matrix_valued());}
|
|
void triqs_gf_view_assign_delegation( gf_view<retime,scalar_valued> g, gf_keeper<tags::fourier,refreq,scalar_valued> const & L) { inverse_fourier_impl(g,L.g, scalar_valued());}
|
|
|
|
}}
|