1*bf2c3715SXin Li MatrixXcd X = MatrixXcd::Random(4,4); 2*bf2c3715SXin Li MatrixXcd A = X + X.adjoint(); 3*bf2c3715SXin Li cout << "Here is a random self-adjoint 4x4 matrix:" << endl << A << endl << endl; 4*bf2c3715SXin Li 5*bf2c3715SXin Li Tridiagonalization<MatrixXcd> triOfA(A); 6*bf2c3715SXin Li MatrixXd T = triOfA.matrixT(); 7*bf2c3715SXin Li cout << "The tridiagonal matrix T is:" << endl << T << endl << endl; 8*bf2c3715SXin Li 9*bf2c3715SXin Li cout << "We can also extract the diagonals of T directly ..." << endl; 10*bf2c3715SXin Li VectorXd diag = triOfA.diagonal(); 11*bf2c3715SXin Li cout << "The diagonal is:" << endl << diag << endl; 12*bf2c3715SXin Li VectorXd subdiag = triOfA.subDiagonal(); 13*bf2c3715SXin Li cout << "The subdiagonal is:" << endl << subdiag << endl; 14