title: Highcharts-ng directive (Angular) not updating
body: <p>I'm using <a href="https://github.com/pablojim/highcharts-ng" rel="nofollow">highcharts-ng</a> Angular-JS directive to draw a chart on my page. </p>
  
  <p>I am hoping to be able to update the data in my controller, and have these values reflected in the graph. However, when I update a $scope variable using assignment eg:</p>
  
  <pre><code>$scope.chartData = [1, 2, 3];
  </code></pre>
  
  <p>...then the graph is not updated. The only way I can get the graph updated is to push a value into the data, eg:</p>
  
  <pre><code>$scope.chartData.push(4);
  </code></pre>
  
  <p>...however this works only the first time it is performed. Here's a JS-fiddle showing what I mean: <a href="http://jsfiddle.net/K6hL8/" rel="nofollow">http://jsfiddle.net/K6hL8/</a></p>
  
  <p>I'm new to Angular so I wanted to check whether there is an obvious problem with my Angular code (maybe I misunderstand $scope and two way bindings?) before I start blaming the third party directive.</p>
  
  <p>Thanks in advance!</p>
  
  <p><strong>Edit:</strong></p>
  
  <p>So it appears (in this fiddle: <a href="http://jsfiddle.net/K6hL8/" rel="nofollow">http://jsfiddle.net/K6hL8/</a>) that Angular <em>does</em> see the change in chartData (I've put a watch with an alert on it), but only when watch is called with "true" for equality. All the watches in the directive use 'true', so I'm stumped... </p>