8   Eigen::Matrix3f m3 = Eigen::Matrix3f::Random();  in main()  local
11   std::cout << "*** Step 1 ***\nm3:\n" << m3 << "\nm4:\n" << m4 << std::endl;  in main()
15   m3.diagonal().setOnes();  in main()
17   std::cout << "*** Step 2 ***\nm3:\n" << m3 << "\nm4:\n" << m4 << std::endl;  in main()
20   m4.block<3,3>(0,1) = m3;  in main()
21   m3.row(2) = m4.block<1,3>(2,0);  in main()
23   std::cout << "*** Step 3 ***\nm3:\n" << m3 << "\nm4:\n" << m4 << std::endl;  in main()
39   m3 = m3.cwise().cos();  in main()
40   std::cout << "*** Step 6 ***\nm3:\n" << m3 << "\nm4:\n" << m4 << std::endl;  in main()
55   m3 = m3 * m4.block<3,3>(1,1); // here Eigen chooses NOT to evaluate block() into a temporary  in main()
61   std::cout << "*** Step 8 ***\nm3:\n" << m3 << "\nm4:\n" << m4 << std::endl;  in main()