void pade (gf_view<refreq> &gr, gf_view<imfreq> const &gw, int n_points, double freq_offset) {
// make sure the GFs have the same structure
//assert(gw.shape() == gr.shape());
// copy the tail. it doesn't need to conform to the pade approximant
gr.singularity() = gw.singularity();
auto sh = gw.data().shape().front_pop();
int N1 = sh[0], N2 = sh[1];
for (int n1=0; n1<N1; n1++) {
for (int n2=0; n2<N2; n2++) {
arrays::vector<dcomplex> z_in(n_points); // complex points
arrays::vector<dcomplex> u_in(n_points); // values at these points
arrays::vector<dcomplex> a(n_points); // corresponding Pade coefficients
for (int i=0; i < n_points; ++i) z_in(i) = gw.mesh()[i];
for (int i=0; i < n_points; ++i) u_in(i) = gw.on_mesh(i)(n1,n2);
triqs::utility::pade_approximant PA(z_in,u_in);
gr() = 0.0;
for (auto om : gr.mesh()) {
dcomplex e = om + dcomplex(0.0,1.0)*freq_offset;
gr[om](n1,n2) = PA(e);
}
}
}
}
void pade(GF_Bloc_ImFreq const & Gw, GF_Bloc_ReFreq & Ge, int N_Matsubara_Frequencies, double Freq_Offset)
{
check_have_same_structure (Gw,Ge,false,true);
assert (Gw.mesh.index_min==0);
assert (Ge.mesh.index_min==0);
double Beta = Gw.Beta;
double omegaShift = (Gw.Statistic==Fermion ? 1 : 0);
Array<COMPLEX,1> z_in(N_Matsubara_Frequencies);
firstIndex i;
z_in = I*Pi/Beta*(2*i+omegaShift);
// Just copy the tail. It doesn't need to conform to the Pade approximant.
Gw.tail = Ge.tail;
int N1 = Gw.N1, N2 = Gw.N2;
for (int n1=1; n1<=N1;n1++)
for (int n2=1; n2<=N2;n2++){
int N = Gw.mesh.len();
Array<COMPLEX,1> u_in(N_Matsubara_Frequencies); // Values at the Matsubara frequencies
Array<COMPLEX,1> a(N_Matsubara_Frequencies); // Pade coefficients
for(int i=0; i < N_Matsubara_Frequencies; ++i){
u_in(i) = (i < N ? Gw.data_const(n1,n2,i) : Gw.tail.eval(z_in(i))(n1,n2));
}
Pade_approximant PA(z_in,u_in);
int Ne = Ge.mesh.len();
Ge.zero();
for (int i=0; i < Ne; ++i) {
COMPLEX e = Ge.mesh[i] + I*Freq_Offset;
Ge.data(n1,n2,i) = PA(e);
}
}
}
