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https://github.com/triqs/dft_tools
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edd1ff4529
A first general restructuration of the doc according to the pattern [tour|tutorial|reference]. In the reference part, objects are documented per topic. In each topic, [definition|c++|python|hdf5] (not yet implemented)
24 lines
545 B
C++
24 lines
545 B
C++
#include <triqs/arrays.hpp>
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#include <triqs/arrays/functional/fold.hpp>
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using namespace triqs;
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double frobenius_norm(arrays::matrix<double> const& a) {
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auto l = [](double r, double x) {
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auto ab = std::abs(x);
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return r + ab * ab;
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};
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return std::sqrt(arrays::fold(l)(a, 0));
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}
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int main() {
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// declare and init a matrix
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clef::placeholder<0> i_;
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clef::placeholder<1> j_;
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arrays::matrix<double> A(2, 2);
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A(i_, j_) << i_ + j_ / 2.0;
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std::cout << "A = " << A << std::endl;
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std::cout << "||A|| = " << frobenius_norm(A) << std::endl;
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}
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