set obs 1000
capture program drop binomial
. program define binomial, rclass
  1. version 12.0
  2. syntax [, obs(integer 1000) p(real 0.2)]
  3. drop _all
  4. set obs 'obs'
  5. tempvar z1 z2
  6. gen 'z1'=uniform()
  7. gen `z2'=(`z1'<`p')
  8. summarize `z2' if `z2'==1
  9. return scalar Num=r(N)
10. end
. qui simulate N=r(Num), reps(10000):binomial, obs(1000) p(0.2)

运行后上述程序后弹出如下出错信息，不知问题出在哪，请求高手相助！
''' found where integer expected
an error occurred when simulate executed binomial
r(198);