绘制散点+连线图:
http://www.cnblogs.com/aaronhoo/p/5150596.html
http://zhidao.baidu.com/link?url=Q1b7NG8eEz-e-pg5PonP1M0A70sctCvfMgyvtjbu7jdGzRQX5TTpg5vqKEvRb1Vc7iRQ2BBp9h--rKHsYLoxH_
其他参考:
http://blog.****.net/baibaibai66/article/details/51260759
http://www.cnblogs.com/harvey888/p/5717098.html
http://www.cnblogs.com/wei-li/archive/2012/05/23/2506940.html