​

​

if (document.getElementById('c')) {

  var C = document.getElementById('c');

  C.width=C.height=800;

  var c = C.getContext('2d');

  var I = c.createImageData(800,800);

​

  //Starting state

  var oldX = 200, oldY = 200, ep = 0.1;

​

  for(var i=0,p=0,x,y;i<100000;i++) {

    //NEW X = OLD X - epsilon * OLD Y 

    x=oldX-ep*oldY%23;

    //NEW Y = OLD Y + epsilon * NEW(!) X

    y=oldY+ep*x%13;

    //convert x,y to array index

    p = (parseInt((x*0.8+(x%y)*0.2)+400)+parseInt(y+400)*C.width)*4;

​

    //plot

    I.data[p+0]=0;

    I.data[p+1]=0;

    I.data[p+2]=0;

    I.data[p+3]=255;

    oldX=x;

    oldY=y;

  }

​

  //draw to canvas

  c.putImageData(I,0,0);

​

}

​