Programming challenges: processing vectors and matrices

[ttw]

Good point. I'll give the COL- and ROW- a try. It looks like I can use COL+ etc. to put things back. The only trick left to get is to get a block out of a matrix (of course, this is not so easy to do efficiently in any language; it's easy to program in high level languages but the access pattern is tough.) There are some irregular patterns too (T or + shaped in various orientations), not much one can do with these.