var options = {
    id: "chart",
	axis: {
		x: {
			tick: {
				rotate: -60
			}
		}
	},
	data: {
		file: {
			url: 'http://csethanhcong.github.io/C9js/data/data_user.json',
			type: 'json'
		},
		keys: {
			name: 'user',
			value: 'access_count'
		}
	}
};
var barChart = new C9.BarChart(options);
barChart.draw();