title: Rerender ng2-google-chart after programmatically changing the data
body: <p>I am using <code>ng2-google-chart</code> and it works fine. Now I want to use some checkboxes to choose which data is shown in the graph.</p>
  
  <p>My graph is connected to the array <code>chartData</code>, which is updated correct after the selection. But the graph does not change. This is my graph</p>
  
  <p><code>&lt;div #graph [chartData]="this.chartData" chartType="AreaChart" GoogleChart&gt;&lt;/div&gt;</code></p>
  
  <p>Is there a way to rerender it after the data is changed?</p>