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https://github.com/triqs/dft_tools
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68 lines
1.3 KiB
ReStructuredText
68 lines
1.3 KiB
ReStructuredText
.. highlight:: c
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.. _gf_imfreq:
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gf<imfreq>
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==========================================================
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This is a specialisation of :ref:`gf_and_view` for imaginary Matsubara frequencies.
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Domain & mesh
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----------------
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Singularity
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-------------
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:ref:`gf_tail`.
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Interpolation method
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---------------------
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None
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Data storage
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---------------
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* `data_t` : 3d array (C ordered) of complex<double>.
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* g.data()(i, range(), range()) is the value of g for the i-th point of the mesh.
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HDF5 storage convention
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---------------------------
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h5 tag : `ImFreq`
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Examples
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---------
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.. compileblock::
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#include <triqs/gfs.hpp>
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using namespace triqs::gfs; using triqs::clef::placeholder;
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int main(){
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double beta=10;
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int Nfreq =100;
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// First give information to build the mesh, second to build the target
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auto GF1 = gf<imfreq> { {beta,Fermion,Nfreq}, {1,1} };
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// or a more verbose/explicit form ...
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auto GF2 = gf<imfreq> { gf_mesh<imfreq>{beta,Fermion,Nfreq}, make_shape(1,1) };
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// Filling the gf with something...
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placeholder<0> wn_;
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GF1(wn_) << 1/ (wn_ + 2);
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// evaluation at n=3
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std::cout << GF1(3) << " == "<< 1/ ( 1_j * std::acos(-1) / beta * (2*3+1) + 2) << std::endl;
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// the high frequency expansion was automatically computed.
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std::cout << GF1.singularity() << std::endl;
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}
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