zoom.scaleExtent([1,1]).translateExtent([[0,0],[xWidth + margins.left + margins.right, height]]).on('zoom',function(){
            wrapper.select('.x.axis').transition().ease(d3.easeCubicOut).call(xAxis.scale(d3.event.transform.rescaleX(x)));
            wrapper.select('.bars').transition().ease(d3.easeCubicOut).attr("transform", d3.event.transform);
    })