mirror of
https://github.com/triqs/dft_tools
synced 2024-11-01 11:43:47 +01:00
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>
|
|
#include <triqs/arrays/functional/fold.hpp>
|
|
using namespace triqs;
|
|
|
|
double frobenius_norm(arrays::matrix<double> const& a) {
|
|
auto l = [](double r, double x) {
|
|
auto ab = std::abs(x);
|
|
return r + ab * ab;
|
|
};
|
|
return std::sqrt(arrays::fold(l)(a, 0));
|
|
}
|
|
|
|
int main() {
|
|
// declare and init a matrix
|
|
clef::placeholder<0> i_;
|
|
clef::placeholder<1> j_;
|
|
arrays::matrix<double> A(2, 2);
|
|
A(i_, j_) << i_ + j_ / 2.0;
|
|
|
|
std::cout << "A = " << A << std::endl;
|
|
std::cout << "||A|| = " << frobenius_norm(A) << std::endl;
|
|
}
|
|
|