1Matrix4d A = Matrix4d::Random(4,4); 2cout << "Here is a random 4x4 matrix:" << endl << A << endl; 3HessenbergDecomposition<Matrix4d> hessOfA(A); 4Matrix4d pm = hessOfA.packedMatrix(); 5cout << "The packed matrix M is:" << endl << pm << endl; 6cout << "The upper Hessenberg part corresponds to the matrix H, which is:" 7 << endl << hessOfA.matrixH() << endl; 8Vector3d hc = hessOfA.householderCoefficients(); 9cout << "The vector of Householder coefficients is:" << endl << hc << endl; 10