We want to use a callback with HighCharts to dynamically change the chart height based on the number of series in the bar chart. This number could be anywhere from 1 to maybe 30 so a fixed height bar chart is not working so well. There are plenty of examples of how to do this when you are using HighCharts directly - but not when using HighCharts through wpDataTables. We have this code that we are using and know it is working for setting the height:

<script type="text/javascript">
jQuery(window).load(function(){
    if( typeof wpDataChartsCallbacks == 'undefined' ){ wpDataChartsCallbacks = {}; }
    wpDataChartsCallbacks[23] = function(obj){
       obj.options.chart.height = 450; 
    }
});
</script>

obj.options.chart.height = obj.series.count * 80;

Is there a way to get the number of series through the callback?

So I was actually able to pull this off without a lot of effort when I realized the data table was on this page and it was possible to get the number of rows in that table (= number of series on the chart +1) by using:

obj.options.chart.height = 80 + (document.getElementById("table_2").rows.length - 1) * 95;

Where "table_2" is the Id of the table in HTML. So hopefully someone else can benefit from this too.