这可能真的很简单，但我就是不知道如何在交易视图小工具中更改股票代码。我希望图表更改为数组中的股票代码。图表需要每30秒更改一次新的股票代码，并永远这样做。
这是我目前得到的：

<div class="tradingview-widget-container">
    <div id="tradingview_5889e"></div>
    <div class="tradingview-widget-copyright"><a href="https://www.tradingview.com/symbols/NYSE-RIG/" rel="noopener" target="_blank"><span class="blue-text">RIG</span> <span class="blue-text">chart</span> by TradingView</a></div>
    <script type="text/javascript" src="https://s3.tradingview.com/tv.js"></script>
    <script type="text/javascript">

    var i = 0
    function createchart(){
      var companies = ['NYSE:SDRL','NYSE:RIG','CHXEUR:SEVDRO','NYSE:TK','CHXEUR:GBBP']
      new TradingView.widget(
      {
      "width": 980,
      "height": 610,
      "symbol": companies[i],
      "interval": "15",
      "timezone": "Etc/UTC",
      "theme": "Light",
      "style": "1",
      "locale": "en",
      "toolbar_bg": "#f1f3f6",
      "enable_publishing": false,
      "hide_top_toolbar": true,
      "save_image": false,
      "hideideas": true,
      "container_id": "tradingview_5889e"
      }
      );
      i++;

    }

    setInterval(createchart(),10000)

    </script>
  </div>

希望你们能帮帮我。我在这上面挣扎太久了。