5   std::cout.precision(2);  in main()
11   std::cout << "*** Step 1 ***\nm3:\n" << m3 << "\nm4:\n" << m4 << std::endl;  in main()
17   std::cout << "*** Step 2 ***\nm3:\n" << m3 << "\nm4:\n" << m4 << std::endl;  in main()
23   std::cout << "*** Step 3 ***\nm3:\n" << m3 << "\nm4:\n" << m4 << std::endl;  in main()
29     std::cout << "*** Step 4 ***\nm4:\n" << m4 << std::endl;  in main()
34   std::cout << "*** Step 5 ***\nm4.diagonal():\n" << m4.diagonal() << std::endl;  in main()
35   std::cout << "m4.diagonal().start(3)\n" << m4.diagonal().start(3) << std::endl;  in main()
40   std::cout << "*** Step 6 ***\nm3:\n" << m3 << "\nm4:\n" << m4 << std::endl;  in main()
43   std::cout << "*** Step 7 ***\n m4.sum(): " << m4.sum() << std::endl;  in main()
44   std::cout << "m4.col(2).sum(): " << m4.col(2).sum() << std::endl;  in main()
45   std::cout << "m4.colwise().sum():\n" << m4.colwise().sum() << std::endl;  in main()
46   std::cout << "m4.rowwise().sum():\n" << m4.rowwise().sum() << std::endl;  in main()
61   std::cout << "*** Step 8 ***\nm3:\n" << m3 << "\nm4:\n" << m4 << std::endl;  in main()