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dft_tools/test/triqs/gfs/test_fit_tail.cpp
2014-02-03 22:22:21 +01:00

78 lines
2.4 KiB
C++

#//define TRIQS_ARRAYS_ENFORCE_BOUNDCHECK
#include <triqs/gfs.hpp>
#include <triqs/gfs/local/fit_tail.hpp>
using triqs::arrays::make_shape;
using namespace triqs::gfs;
using triqs::gfs::local::tail;
#define TEST(X) std::cout << BOOST_PP_STRINGIZE((X)) << " ---> "<< (X) <<std::endl<<std::endl;
int main() {
double precision=10e-9;
triqs::clef::placeholder<0> iom_;
double beta =10;
int N=100;
auto gw = gf<imfreq>{{beta, Fermion, N}, {1, 1}};
triqs::arrays::array<double,1> c(3);
triqs::clef::placeholder<1> i_;
c(i_) << (2*i_+1);
int size=0; //means we don't know any moments
int order_min=1; //means that the first moment in the final tail will be the first moment
auto known_moments = tail(make_shape(1,1), size, order_min); //length is 0, first moment to fit is order_min
gw(iom_) << c(0)/iom_ + c(1)/iom_/iom_ + c(2)/iom_/iom_/iom_;
//show tail
// std::cout<< "before fitting:" <<std::endl;
// for(auto &i : gw.singularity().data()) std::cout << i << std::endl;
//erase tail
for(auto &i : gw.singularity().data()) i = 0.0;
size_t wn_min=50; //frequency to start the fit
size_t wn_max=90; //final fitting frequency (included)
int n_moments=3; //number of moments in the final tail (including known ones)
//restore tail
set_tail_from_fit(gw, known_moments, n_moments, wn_min, wn_max);
// std::cout<< "after fitting:" <<std::endl;
// for(auto &i : gw.singularity().data()) std::cout << i << std::endl;
for(size_t i=0; i<first_dim(c); i++){
double diff = std::abs( c(i) - gw.singularity().data()(i,0,0) );
//std::cout<< "diff: " << diff <<std::endl;
if (diff > precision) TRIQS_RUNTIME_ERROR<<" fit_tail error : diff="<<diff<<"\n";
}
//erase tail
for(auto &i : gw.singularity().data()) i = 0.0;
//now with a known moment
size=1; //means that we know one moment
order_min=1; //means that the first moment in the final tail will be the first moment
known_moments = tail(make_shape(1,1), size, order_min); //length is 0, first moment to fit is order_min
known_moments(1)=1.;//set the first moment
set_tail_from_fit(gw, known_moments, n_moments, wn_min, wn_max, true);//true replace the gf data in the fitting range by the tail values
for(size_t i=0; i<first_dim(c); i++){
double diff = std::abs( c(i) - gw.singularity().data()(i,0,0) );
//std::cout<< "diff: " << diff <<std::endl;
if (diff > precision) TRIQS_RUNTIME_ERROR<<" fit_tail error : diff="<<diff<<"\n";
}
}