Rounding out today’s flurry of posts, a quick note to the effect that Sylvester is now at version 0.1.3. The 0.1.2 release missed a couple of bugs that I meant to fix with it. Well not bugs, as such, but places where value/reference ambiguity could have caused problems. I’m beginning work on 0.2 again, after a long break focusing on other projects and house hunting. This should be the final 0.1 release, unless I find any particularly catastrophic bugs.
MrABC added these pithy words on Nov 17 08 at 11:10 amHello! i have a question.
ex:
i have 4 point (a rectangle)
and i want to rotate them in 90°code:
angle = Math.PI/2;var a = $M([
[2,2,0],
[2,5,0],
[7,5,0],
[7,5,0]
]);var b = $V([7,2,0]);
R = Matrix.Rotation(angle);
test = R.add(a.elements);
MrABC added these pithy words on Nov 17 08 at 11:13 amsry i wrote wrong, sory
ex:
i have 4 point (a rectangle)
and i want to rotate them in 90°code:
angle = Math.PI/2;var a = $M([
[2,2,0],
[2,5,0],
[7,5,0],
[7,2,0]
]);R = Matrix.Rotation(angle);
result = R.add(a);Dis i do wrong? i try to read the Tutorial
http://sylvester.jcoglan.com/api/matrixbut i cant get it! sry
can you help me?
James added these pithy words on Nov 19 08 at 11:08 amYou’re trying to add two matrices of different sizes, which doesn’t make mathematical sense. The way to model your problem is with vectors: vectors represent single points in space.
var rect = [$V([2,2]), $V([2,5]), $V([7,5]), $V([7,2])];Then you multiply each point with the rotation matrix to transform them:
var rot = Matrix.Rotation(Math.PI/2), i = rect.length; while (i--) rect[i] = rot.x(rect[i]);Or, use the Vector#rotate method.
