c3 Scatter Chart - Bubble Chart

HTML

<script src="http://c3js.org/js/jquery-1.11.0.min-910066fb.js"></script>
<link rel="stylesheet" href="http://c3js.org/css/c3-f750e4d4.css">
<script src="http://c3js.org/js/d3.min-3bff8220.js"></script>
<script src="http://c3js.org/js/c3.min-b4e07444.js"></script>
<div id="chart"></div>

JavaScript

var chart = c3.generate({
    data: {
        columns: [
            ['data1', 30],
            ['data2', 120],
        ],
        type : 'donut',
        selection: {
          enabled: true,
          grouped: true,
          multiple: true
        },
        onselected: function(d, i) { 
            console.log('selected');    
        }
    },
    donut: {
        title: "Iris Petal Width"
    }
});