title: Sort of series values for xAxis
body: <p>I've two different line charts. One with a datetime xAxis and another one with a linear xAxis.</p>
  
  <p>I've noticed that the order of the series values does not matter, if the xAxis type is datetime. Highcharts matches the values automatically.</p>
  
  <pre><code>    series: [{
          data: [[Date.UTC(2010, 0, 1), 29.9], 
                 [Date.UTC(2010, 0, 2), 71.5]]
      },
      {
          data: [[Date.UTC(2010, 0, 2), 61.5],
                 [Date.UTC(2010, 0, 1), 19.9]]
      }]
  </code></pre>
  
  <p>Result: <a href="http://jsfiddle.net/c6hvu/" rel="nofollow">http://jsfiddle.net/c6hvu/</a></p>
  
  <p>But in the second chart I've a linear xAxis and two series with values in different orders two. Additionally I've defined categories for the xAxis. Nevertheless the values aren't matched automatically. This results in a charts with wrong values. </p>
  
  <pre><code>    series: [{
          data: [{name: 'First', y: 20}, 
                 {name: 'Second', y: 50}]
      },
      {
          data: [{name: 'Second', y: 40},
                 {name: 'First', y: 10}]
      }]
  </code></pre>
  
  <p>Result: <a href="http://jsfiddle.net/xXkPt/" rel="nofollow">http://jsfiddle.net/xXkPt/</a></p>
  
  <p>My questions are:</p>
  
  <ol>
  <li>Is this behaviour intended or is this a bug?</li>
  <li>Why does Highcharts matched datetime charts but not linear charts with categories?</li>
  <li>Is there any way to match the series values for a linear chart too?</li>
  </ol>
  
  <p>Thank you</p>
  
  <p>Torben</p>