docs: function(x, y, disablePlot) {
        var px = this.scaleOffsetX * x,
            py = this.scaleOffsetY * y;
        var dx = this.translateOffsetX * (x -1) / px,
            dy = this.translateOffsetY * (y -1) / py;
        this.scaleOffsetX = px;
        this.scaleOffsetY = py;
        for(var i=0, l=this.canvases.length; i<l; i++) {
          this.canvases[i].scale(x, y, true);
        }
        this.translate(dx, dy, false);
      }