<html>
  <head>
    <link href="/css/c3.css" rel="stylesheet" type="text/css">
  </head>
  <body>
    <div id="chart"></div>

    <script src="http://d3js.org/d3.v3.min.js" charset="utf-8"></script>
    <script src="/js/c3.js"></script>
    <script>
      var chart = c3.generate({
        data: {
          columns: [
            ['data1', 30, 200, 100, 400, 150, 250, 100, 600],
            ['data2', 50, 20, 10, 40, 15, 25],
          ]
        },
        axis: {
//          rotated: true,
          x: {
            tick: {
              format: function () { return "hogehogehogehogehoge"; },
              rotate: 30,
            },
            label: {
              text: 'Hogehoge',
              position: 'outer-middle'
            },
            height: 90,
          },
          y: {
            label: {
              text: 'Y Label',
              position: 'outer-center'
            }
          }
        },
        subchart: {
          show: true
        }
      });

      setTimeout(function () {
        chart.load({
          columns: [
//            ['data1', 30, 200, 100, 400, 150, 250, 100, 400],
            ['data1', 1030, 2000, 1000, 1400, 1500, 1250, 1100, 140000],
          ]
        })
      }, 1000);


    </script>
  </body>
</html>

Add sample for axis x tick rotate
Add sample for axis x tick rotate
