1 Matrix3d m = Matrix3d::Random();
2 cout << "Here is the matrix m:" << endl << m << endl;
3 cout << "Here is the sum of each column:" << endl << m.colwise().sum() << endl;
4 cout << "Here is the maximum absolute value of each column:"
5      << endl << m.cwiseAbs().colwise().maxCoeff() << endl;
6