runman 发表于 2016-4-3 17:02 
好的,谢谢啦
stata有个面板数据的例子,希望能对你有帮助!
. webuse ipolxmpl2, clear
Show years for which the circulation data are missing
. tabulate circ year if circ == ., missing
Create icirc containing a linear interpolation of circ on year for missing values of
circ and perform this calculation separately for each magazine
. by magazine: ipolate circ year, gen(icirc)