Talk:184: Matrix Transform

This baby needs a bit more rigor. --Quicksilver (talk) 05:23, 24 August 2013 (UTC)

I think this is also a reference to the movie "The Matrix", specifically the now famous scene where Neo does 90degree back bending to dodge bullets. 173.245.62.84 07:54, 7 April 2014 (UTC)

Maybe another reference: They'll go home (translation matrix) and shrink (scale matrix). Translation, scale and rotate are probably the most popular linear transformations. 108.162.218.89 23:39, 14 May 2014 (UTC)

I've been teach that the rotation was anticlockwise. Do computer turn the other way round that math teachers? by the way (left ( matrix{0 # 1 ## -1 # 0} right )*left ( binom 1 0 right)=left (binom 0 1 right) if you know what i mean. get fun. Yomismo (talk) 09:28, 18 March 2015 (UTC)

IIIII'm pretty sure the "shrink" is a typo, and he meant "drink". My evidence is the xkcd book, where he just flat-out says it. 162.158.178.97 (talk) 12:57, 16 April 2019 (UTC) (please sign your comments with ~~~~)

On clockwise/counterclockwise: I think Randall is using screen coordinates (where the top left is (0,0) and the point (1,4) is one below (1,3)), instead of standard Cartesian coordinates where the bottom left is (0,0) and going from (1,3) to (1,4) means going upwards. 162.158.155.170 13:07, 17 May 2019 (UTC)

RE positive or negative rotation: The rotation of the vector is 90 degrees in the NEGATIVE direction, but also notice that the matrix has the off-diagonal minus sign in the opposite place from where it would be for a positive rotation in a right-handed coordinate system. The interpretation of this is that either a) RM is using a left-handed coordinate system, instead of the typical right-handed one, or b) he took the matrix for rotating by -90 degrees and simplified by moving in the minus out of the trig functions. Either way, the math is correct, but slightly confusing. (source: I teach CS 184) 136.144.42.175 (talk) 22:46, 22 February 2026 (UTC) (please sign your comments with ~~~~)