4 thoughts on “Sylvester 0.1.3”

1. 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);

2. 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?

3. 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.

4. 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.