#include <cxxstd/iostream.h>
#include <flens/flens.cxx> using namespace std; using namespace flens; int main() { typedef complex<double> Complex; const Complex I(0,1); GeMatrix<FullStorage<Complex> > A(4,4); DenseVector<Array<Complex> > b(4); DenseVector<Array<Complex> > tau; //DenseVector<Array<Complex> > work; A = 2, 3, -1, 0, -6, -5, 0, 2, 2, -5, 6, -6, 4, 6, 2, -3; A *= I; b = 20, -33, -43, 49; b *= I; cout << "A = " << A << endl; cout << "b = " << b << endl; /// /// Compute the factorization $A = QR$. Note that the workspace gets created /// implicitly and temporarily. So you might not want to do this inside a loop. /// lapack::qrf(A, tau); //lapack::qrf(A, tau, work); /// /// Compute $\tilde{b} = Q^T b$. Note that we do not setup $A$ explicitly. /// lapack::unmqr(Left, ConjTrans, A, tau, b); // lapack::ungqr(A, tau, b, work); /// /// Solve $R x = \tilde{b}$. Vector $b$ gets overwritten with $x$. /// const auto R = A.upper(); blas::sv(NoTrans, R, b); cout << "x = " << b << endl; } |