Comments on: Sylvester 0.1.3

By: Jan Theodore Galkowski

Jan Theodore Galkowski — Thu, 05 Mar 2009 19:06:35 +0000

Anyone port Sylvester to Actionscript? Even though they have a Matrix class, there’s little support. There is a Clevrlib1 which has some more, including SVD and QR decomposition, but it doesn’t support Vector, Plane, Line, except as special cases of Matrix.

By: James Coglan

James Coglan — Wed, 19 Nov 2008 11:08:12 +0000

You'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.

By: MrABC

MrABC — Mon, 17 Nov 2008 11:13:47 +0000

sry 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/matrix

but i cant get it! sry
can you help me?

By: MrABC

MrABC — Mon, 17 Nov 2008 11:10:47 +0000

Hello! 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);