title: Highcharts set x-axis categories
body: <p>I am drawing my graph,</p>
  <pre><code>Data.chart.series[0].remove();
  Data.chart.xAxis[0].axisTitle.attr({ text: xAxisTitle});
  //Data.chart.xAxis[0].categories = xAxisCategories;
  Data.chart.addSeries({
    name: yAxisTitle,
    data: formattedData,
    pointInterval: pointInterval
  });
  Data.chart.redraw();
  </code></pre>
  <p>I simply can't see anything in the documentation for changing the xAxis categories, is this possible? I couldn't see anything 4 changing the title, but managed to get a snippet online, I really need to avoid destroying &amp; recreating the graph.</p>