title: Set zero for missing data in echarts.js
body: <p>I want to combine 2 or more line charts having dates in x-axis and values in y-axis. But the dates for some series do not match. </p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>series0X= ["2015-11-21","2017-09-21"];
  series1X= ["2017-09-21","2017-10-22","2017-11-20"];
  series2X= ["2018-05-21","2018-09-22","2018-10-20","2018-11-21"]
  
  series0Y=["5","8"];
  series1Y=["3","4","7"];
  series2Y= ["2","9","6","1"];</code></pre>
  </div>
  </div>
  </p>
  
  <p>I have merged and sorted Dates array for x-axis:</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>DatesX = ["2015-11-21", "2017-09-21", "2017-10-22", "2017-11-20", "2018-05-21", "2018-09-22", "2018-10-20", "2018-11-21"];</code></pre>
  </div>
  </div>
  </p>
  
  <p>I want the y axis series values to be like this:</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>series0Y= ["5","8","0',"0","0", "0", "0", "0"]
  series1Y= ["0","3","4',"7","0", "0", "0", "0"]
  series2Y= ["0","0","0',"0","2","9","6","1"]</code></pre>
  </div>
  </div>
  </p>
  
  <p>Chart Code Editor Ref:  <a href="http://gallery.echartsjs.com/editor.html?c=xB1-xTeDC-" rel="nofollow noreferrer">http://gallery.echartsjs.com/editor.html?c=xB1-xTeDC-</a></p>
  
  <p><a href="https://i.stack.imgur.com/D3kiB.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/D3kiB.png" alt="enter image description here"></a></p>