sungmoo 发表于 2013-6-16 18:25 
https://bbs.pinggu.org/thread-2158471-2-1.html
xtset code year
code year prof t t2
1 3/31/2002 .09 .09 .0081
1 6/30/2002 .07 .07 .0049
1 9/30/2002 .06 .06 .0036
1 12/31/2002 0 0 0
1 3/31/2003 -.141 -.141 .019881
1 6/30/2003 .061 .061 .003721
1 9/30/2003 .02 .02 .0004
1 12/31/2003 0 0 0
1 3/31/2004 -.05 -.05 .0025
1 6/30/2004 .04 .04 .0016
1 9/30/2004 .06 .06 .0036
1 12/31/2004 -.06 -.06 .0036
1 3/31/2005 -.07 -.07 .0049
1 6/30/2005 .03 .03 .0009
1 9/30/2005 .08 .08 .0064
您第二个方法很好,太高了,但是我用您的方法,感觉没有平滑的过程,我这里是哪里出了问题,谢谢指导。