1 Matrix4d X = Matrix4d::Random(4,4); 2 Matrix4d A = X + X.transpose(); 3 cout << "Here is a random symmetric 4x4 matrix:" << endl << A << endl; 4 Tridiagonalization<Matrix4d> triOfA(A); 5 Vector3d hc = triOfA.householderCoefficients(); 6 cout << "The vector of Householder coefficients is:" << endl << hc << endl; 7