1 Matrix3d m = Matrix3d::Zero(); 2 m.triangularView<Eigen::Upper>().setOnes(); 3 cout << "Here is the matrix m:\n" << m << endl; 4 Matrix3d n = Matrix3d::Ones(); 5 n.triangularView<Eigen::Lower>() *= 2; 6 cout << "Here is the matrix n:\n" << n << endl; 7 cout << "And now here is m.inverse()*n, taking advantage of the fact that" 8 " m is upper-triangular:\n" 9 << m.triangularView<Eigen::Upper>().solve(n) << endl; 10 cout << "And this is n*m.inverse():\n" 11 << m.triangularView<Eigen::Upper>().solve<Eigen::OnTheRight>(n); 12