code: function(left,top){
              return {
                  x:Math.ceil(-left / this._tile.width - (top & 1)*0.5),
                  y:-top / this._tile.height * 2
              }; 
          }
docs: @
  #Crafty.isometric.px2pos
  @comp Crafty.isometric
  @sign public this Crafty.isometric.px2pos(Number left,Number top)
  @param top
  @param left
  @return Object {x Number,y Number}
  
  This method calculate pixel top,left positions to x,y coordinates
  
  @example
  ~~~
  var iso = Crafty.isometric.size(128,96);
  var px = iso.pos2px(12800,4800);
  console.log(px); //Object { x=-100, y=-100}
  ~~~