黃河泉 发表于 2018-12-4 15:52 
试试
gen t = _n
. tsset t
time variable: t, 1 to 56
delta: 1 unit
. forv i=6/8 {
2. if idd==`i'{
3. tsspell x
4. bys _spell: egen m = max(_seq)
5. egen mm = max(m)
6. keep if m == mm
7. }
8. }
(50 observations deleted)
warning: data contain gaps; see help on tsspell
_end already defined
r(110);
这是提示