Get a matrix from a patcher to javascript?

    Oct 20 2011 | 4:16 pm
    Could Anyone explain how to get a matrix from a patcher and process it inside javascript.
    What kind of function do I need in JS?
    Tutorials explain how to send a processed matrix from javascript out of the [js] object with the outlet() method, to the patcher but not how to retrieve a matrix inside the [js] FROM the patcher.

    • Oct 20 2011 | 4:47 pm
      Here's how to get a matrix object in JS with the same data as the input matrix name.
      function jit_matrix(name) {
      // create matrix with the same name as the input matrix
      var mat = new JitterObject("jit.matrix", name);
      var cell = mat.getcell(0, 0);
      post("res: "+cell+"n");
    • Oct 21 2011 | 2:10 pm
      Okay, thank you, nice, but how do I process the matrix now?
      Does it need to be inside the function itself. After several attempt this not works:
      var mydimmap = new JitterObject("jit.dimmap");
      mydimmap.invert = [1, 1];
      var mtrx2 = new JitterMatrix(4, "char", 320, 240 );
      mtrx2.adapt = 1;
      function jit_matrix(ext)
      var mtrx = new JitterObject("jit.matrix", ext);
      mtrx2.matrixcalc(mtrx, mydimmap);
      outlet(0, "jit_matrix",;
      >>> Javascript TypeError: mtrx2.matrixcalc is not a function, line 15
      I can't achieve to process the matrix inside another function anymore.
      This lacks in the JS tutorials.
    • Oct 22 2011 | 12:32 pm
      Okay, after a good night I go this way:
      autowatch = 1;
      var mtrx = new JitterMatrix(4, "char", 320, 240);
      var opfloat;
      function recupop(v)
      opfloat = v;
      function bang()
      mtrx.op("*", opfloat);
      function jit_matrix(ext)
      { = ext;
      outlet(0, "jit_matrix",;
    • Oct 22 2011 | 12:40 pm
      I am aware that this code is elementary for programmers, but I'm not, I'm only an artist and I think Max is really interesting for its accessibility and documentation. Such basic code should be in the doc because it would allow to gain some days ... yes. I think we need needs more JS basic tutorials ...
      Anyway thanks for the example, Wes, on how to retrieve the matrix in JS.
      (more, more, more ;-)