  class="language-js d-none d3v4-chunk"
            ><code id="code-js-v4" contenteditable="true"><xmp><script>

// create 2 data_set
var data1 = [
   {group: "A", value: 4},
   {group: "B", value: 16},
   {group: "C", value: 8}
];

var data2 = [
   {group: "A", value: 7},
   {group: "B", value: 1},
   {group: "C", value: 20},
   {group: "D", value: 10}
];

// set the dimensions and margins of the graph
var margin = {top: 30, right: 30, bottom: 70, left: 60},
    width = 460 - margin.left - margin.right,
  