非常感谢您的帮助，最后请教一下：
请问第四个问题怎么解决？

怎么批量修改变量名，比如我有1000个字段名，分别是*1,*2,*3,*4,*5,*6,*7....，我怎么样全部把*去掉或者改成其他名字；

请问怎么打印变量的第一行？
谢谢你

你说的第四个是统计问题，我不是统计学出身，还是等高人讲解。

批量改名的问题，我只知道在data步中，用rename进行处理，如果变量较多，你可以借助EXCEL写个函数，再把语句复制出来，不知道高人有没有其它方法。

打印功能，呃，木有使用过

爱莫能助了~

非常感谢您，请问一下：

如果按照您第一次给我的方法，如何计算每个人，比如小明，不同id的num总数以及平均值等等相关的统计量。

因为我的数据不单单是X1a，X2b,X3c,X4d四个而已，因此需要做循环，我最终目的是做不同id的num的统计，请你指教，谢谢。

{"_id":{"$oid":"558d2bb91dc76a2178188c3e"},"age":"29","degree":1,"gender":"男","id":"558d2bb91dc76a2178188c3e","major":"电子商务","workExperienceList":[{"department":null,"end_date":"2015-03","industry":"计算机硬件 ","position_name":"电子商务经理","salary":4,"size":6,"start_date":"2014-11","type":"-"},{"department":null,"end_date":"2014-10","industry":"互联网/电子商务 ","position_name":"运营经理","salary":3,"size":4,"start_date":"2012-08","type":"-"},{"department":null,"end_date":"2012-07","industry":"房地产/建筑/建材/工程 ","position_name":"运营经理","salary":2,"size":4,"start_date":"2010-07","type":"-"},{"department":null,"end_date":"2010-05","industry":"互联网/电子商务 ","position_name":"运营专员","salary":2,"size":7,"start_date":"2009-11","type":"-"}]}
{"_id":{"$oid":"558d2bb91dc76a2178188c40"},"age":"28","degree":1,"gender":"男","id":"558d2bb91dc76a2178188c40","major":"计算机科学与技术","workExperienceList":[{"department":null,"end_date":"至今","industry":"IT服务(系统/数据/维护) ","position_name":"技术支持","salary":1,"size":4,"start_date":"2014-10","type":"-"},{"department":null,"end_date":"2014-08","industry":"基金/证券/期货/投资 ","position_name":"信息技术专员","salary":2,"size":2,"start_date":"2014-03","type":"-"},{"department":null,"end_date":"2014-03","industry":"房地产/建筑/建材/工程 ","position_name":"信息技术专员","salary":1,"size":7,"start_date":"2011-11","type":"-"}]}
{"_id":{"$oid":"558d2bba1dc76a2178188c6f"},"age":"29","degree":1,"gender":"男","id":"558d2bba1dc76a2178188c6f","major":"计算机信息管理","workExperienceList":[{"department":null,"end_date":"至今","industry":"计算机软件 ","position_name":"软件测试","salary":3,"size":7,"start_date":"2013-11","type":"-"},{"department":null,"end_date":"2013-11","industry":"计算机软件 ","position_name":"软件测试","salary":2,"size":6,"start_date":"2012-11","type":"-"},{"department":null,"end_date":"2012-06","industry":"计算机软件 ","position_name":"开发工程师","salary":2,"size":6,"start_date":"2009-12","type":"-"}]}
{"_id":{"$oid":"558d2bbc1dc76a2178188d1b"},"age":"27","degree":1,"gender":"男","id":"558d2bbc1dc76a2178188d1b","major":null,"workExperienceList":[{"department":null,"end_date":"至今","industry":"大型设备/机电设备/重工业 ","position_name":"技术支持","salary":2,"size":2,"start_date":"2013-11","type":"-"},{"department":null,"end_date":"2013-08","industry":"办公用品及设备 ","position_name":"质量(QA/QC)","salary":2,"size":5,"start_date":"2013-05","type":"-"},{"department":null,"end_date":"2013-04","industry":"加工制造（原料加工/模具） ","position_name":"机械工程师","salary":1,"size":6,"start_date":"2011-07","type":"-"}]}






如果读取如此复杂的数据该如何操作呢？？求得大神指点。

很有意思的讨论，学习了

第四个问题，可以阅读一下SAS Oversampling 部分，考虑1：3？