The first is to place the script tags where you build and render the visualization inside the div
tags, something like this:
<div>
    <script>
        ...
        vis.render();
    </script>
</div>
The other way, an this always work is to specify where it will be shown, something like this:
<script>
    ...
    var vis = new pv.Panel()
        .canvas($("vocabulary_chart"))
    ....
</script>
So It will be shown inside the div you specified.
Hope this helps you.
