PROSAGA码农传奇-数据融合-c3js中的数据聚合

<div class =“post-text”itemprop =“text”>
  <P>
    据我所知，没有内置到c3中。您可以使用d3的嵌套运算符来聚合json数据，然后再将其传递给c3。
  </p>
   <pre>
    <code>
      var json = [
            {name: 'name1', upload: 200, download: 200, total: 400},
            {name: 'name1', upload: 100, download: 300, total: 400},
            {name: 'name2', upload: 300, download: 200, total: 500},
            {name: 'name3', upload: 400, download: 100, total: 500},
          ];

var agg = function (json, nestField) {
        var nested_data = d3.nest()
            .key(function(d) { return d[nestField]; })
            .rollup(function(leaves) { 
                // Work out the fields we're not nesting by
                var keys = d3.merge (leaves.map (function(leaf) { return d3.keys(leaf); }));
                var keySet = d3.set(keys);
                keySet.remove (nestField);
                var dataFields = keySet.values();

// total these fields up
                // console.log(leaves, dataFields); // just for testing
                var obj = {};
                dataFields.forEach (function (dfield) {
                    obj[dfield] = d3.sum(leaves, function(d) {return d[dfield];});
                });
                return obj; 
            })
            .entries(json);

// return to original json format
        var final_data = nested_data.map (function(nestd) {
            nestd.values[nestField] = nestd.key;
            return nestd.values;
        });

return final_data;
    };

var chart = c3.generate({
        bindto:'#png-container',
        data: {
          json: agg(json, "name"),
          keys: {
            x: 'name', // it's possible to specify 'x' when category axis
            value: ['upload', 'download'],
          },
          groups: [
            ['name']
          ]
        },
        axis: {
          x: {
            type: 'category'
          }
        }
    });

</code>
  </pre>
  <P>
    <a href="https://jsfiddle.net/8uofn7pL/2/" rel="nofollow">
      https://jsfiddle.net/8uofn7pL/2/
    </A>
  </p>
  <P>
    哎呀，与错误的小提琴相关联
  </p>
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