我的代码时这样的
program randwalk2,rclass
drop _all
set obs 25
gen eps = rnormal()
gen y = sum(eps)
gen t = _n
tsset t
sysuse auto
constraint 1 l.y = 1
constraint 2 t = 0
cnsreg y l.y,constraints(1-2)
return scalar F = e(F)
end

simulate Fvalue = r(F),seed(10101) reps(10000):randwalk2 save()
simulate的命令报错：
no; data in memory would be lost
an error occurred when simulate executed randwalk2
r(4);
求助各位大佬，这个怎么解决呀