1 MatrixXcf A = MatrixXcf::Random(4,4); 2 HessenbergDecomposition<MatrixXcf> hd(4); 3 hd.compute(A); 4 cout << "The matrix H in the decomposition of A is:" << endl << hd.matrixH() << endl; 5 hd.compute(2*A); // re-use hd to compute and store decomposition of 2A 6 cout << "The matrix H in the decomposition of 2A is:" << endl << hd.matrixH() << endl; 7