title: Attach correct data format to draw a chart
body: <p>I'm new to Vuejs, vue-Chartkick, and Chartjs. I was trying to insert the restructured data into an object to draw a multiple-series chart. But it did not work.</p>
  <pre><code>&lt;template&gt;
      &lt;line-chart :data=&quot;data&quot;&gt;&lt;/line-chart&gt;
  &lt;/template&gt;
  
  &lt;script&gt;
  import axios from &quot;axios&quot;;
  export default {
      name: 'SummaryGraph',
      data () {
          return {
              data: [
                {name: 'A', data: {}},
                {name: 'B', data: {}}
              ]
          }
      },
      created() {
          let apiURL_1 = axios.get('http://localhost:3000/MyfirstData');
          let apiURL_2 = axios.get('http://localhost:3000/MysecondData');
  
          axios.all([apiURL_1, apiURL_2]).then(axios.spread((first_response, second_response) =&gt; {
              this.data[0]['data'] = first_response.data.reduce(function(result, current) {return Object.assign(result, current);}, {});
              this.data[1]['data'] = second_response.data.reduce(function(result, current) {return Object.assign(result, current);}, {});
          })).catch(error =&gt; {
              console.log(error)
          });
      }
  }
  &lt;/script&gt;
  </code></pre>
  <p><strong>The 1st original returned data:</strong></p>
  <pre><code>[{&quot;A&quot;:6},{&quot;B&quot;:6},{&quot;C&quot;:4}]
  </code></pre>
  <p><strong>The 2nd original returned data:</strong></p>
  <pre><code>[{&quot;A&quot;:1},{&quot;B&quot;:2},{&quot;C&quot;:2}]
  </code></pre>
  <p>The 1st data after restructured by using reduce method.</p>
  <pre><code>{&quot;A&quot;: 6,&quot;B&quot;: 6,&quot;C&quot;: 4}
  </code></pre>
  <p>The 2nd data after restructured by using reduce method.</p>
  <pre><code>{&quot;A&quot;: 1,&quot;B&quot;: 2,&quot;C&quot;: 2}
  </code></pre>
  <p>If I directly insert the 1st and 2nd restructured data into the Vue instance
  Like this:</p>
  <pre><code>&lt;script&gt;
  export default {
      name: 'SummaryGraph',
      data () {
          return {
              data: [
                {name: 'A', data: {&quot;A&quot;: 6,&quot;B&quot;: 6,&quot;C&quot;: 4}},
                {name: 'B', data: {&quot;A&quot;: 1,&quot;B&quot;: 2,&quot;C&quot;: 2}}
              ]
          }
      }
  }
  &lt;/script&gt;
  </code></pre>
  <p>It worked. The graph showed up. I don't know why.</p>