title: ngx-charts: set number of max. displayed labels/ticks on xAxis and prevent rotation
body: <p>In a ngx-area-chart i want to set the max. displayed labels on the xAxis to 5.
  If i have only a few values this works as expected (left example), but with more data, the labels begin to rotate and it looks like the right example in this screen:</p>
  
  <p><a href="https://i.stack.imgur.com/bBmBm.png" rel="nofollow noreferrer">screenshot</a></p>
  
  <p>I want to have only 5 labels on the xAxis and not rotated, independent of the number of values in the chart. I played around with this <a href="https://plnkr.co/edit/6HkONlHQ7pGHTgapt6vx" rel="nofollow noreferrer">plunker</a> by only changin the values in the data.ts:</p>
  
  <pre><code>export var multi = [{
  'name': 'Data',
  'series': [
    {"name":"24 Aug 12:30","value":"1.35870168"},
    {"name":"24 Aug 12:40","value":"3.92566715"},
    {"name":"24 Aug 12:50","value":"8.5667666"},
    {"name":"24 Aug 13:00","value":"5.25927041"},
    {"name":"24 Aug 13:10","value":"4.99596386"},
  
    ....
  
  ]}];
  </code></pre>
  
  <p>Any help is much appreciated.</p>