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https://github.com/triqs/dft_tools
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49 lines
1.3 KiB
ReStructuredText
49 lines
1.3 KiB
ReStructuredText
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.. highlight:: c
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.. _gf_clef:
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Interaction with CLEF expressions
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============================================
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* The gf containers and their view classes can be used with the :doc:`../clef/contents` library :
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* They can be called with CLEF expressions.
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* :doc:`Automatic assignment<../clef/assign>` has been set up.
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* Using the CLEF library offers a quick and efficient way to fill an array with multiple advantages :
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* It is simpler and more readeable than a series of for loops.
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* It is usually more optimal since the for loops are automatically written in the TraversalOrder of the array.
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* **Example** :
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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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// Cf gf<imfreq> specialisation page for the constructor
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double beta=10; int Nfreq =100;
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auto g = gf<imfreq> { {beta,Fermion,Nfreq}, {1,1} };
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// Filling the gf with something...
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placeholder<0> wn_;
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g(wn_) << 1/ (wn_ + 2);
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g(wn_) << 1/ (wn_ + 2 + g(wn_) );
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}
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.. note::
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The syntax uses a <<, not = since the array is not assigned to an expression
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but filled by the evaluation thereof.
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The LHS uses () and not brackets, even though it is on the mesh, because of the strange C++ limitation
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that [] can not be overloaded for several variables...
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