force Highcharts redraw animation when changing graph type
<p>I have a bunch of graphs that by default, come out as line graphs.  I've added buttons to the side of my graph to allow the user to change it to a pie, bar, areaspline, or back to line.</p>

<p>When the user clicks the button, it runs this function:</p>

<pre><code>function change_graph_type(moduleNumber, type) {

  graph_type = type;

  var chart    = $('#graph' + moduleNumber).highcharts();

  for ( i=0;i&lt;chart.series.length;i++ ) {
    chart.series[i].update({
      type      : graph_type
    });
    //chart.redraw();  //I've tried adding this here to no avail...
  } 
}
</code></pre>

<p>The code changes each series from e.g. - line to bar, or bar to areaspline, but I cannot figure out how to get the "animation" when the user toggles over to that new graph type, so it only runs the very first time the user generates the chart.</p>