3 ms·
Are they multiplying a 3x3 matrix by a 2 component vector ?
by d-lisp 11mo ago
Are they multiplying a 3x3 matrix by a 2 component vector ?
- tptacek 11mo agoIn that one case, yeah; I don't think they're going for anything more than general illustration here.
- magicalhippo 11mo agoThe text that follows does take on a new meaning though, for those that know linear algebra: If the mere sight of the above is like a punch in the face for you, don't worry. Almost makes me wonder if it was intentional.
- tptacek 11mo agoBears. Beets. Battlestar Galactica!
- nyeah 11mo agoBut what does that illustrate?
- tptacek 11mo agoLike, what a matrix looks like? Seems fine.
- nyeah 11mo agoBut, as a few people have pointed out, that particular matrix product is undefined. It's broken. That's really not quite what a matrix-vector product looks like. The author says he has PhD. That's fine. I suffer from the same condition. But it feels off to hear about expertise and see an invalid first example.
- seanhunter 11mo agoYeah that made me twitch also.
- wjholden 11mo agoIt also has mixed square brackets and curved parentheses. I stopped reading the article when I saw this.
- nyeah 11mo agoBrackets can be any shape, it's fine. Like (3)*[4] is still 12. But that matrix-vector product is undefined.
- moron4hire 11mo agoEveryone knows you need a 4x4 matrix to do translation, anyway. Now, scale, rotation, and skew...