http://www.imooc.com/article/1427 20 个最棒的 javascript 图表库
http://echarts.baidu.com/index.html echarts.js | 百度
http://echarts.baidu.com/tutorial.html#5%20%E5%88%86%E9%92%9F%E4%B8%8A%E6%89%8B%20ECharts
http://echarts.baidu.com/echarts2/doc/start.html
how to get data dynamically: