H(i,t) = | P(i,t) - P(t) | - AF(i,t)
其中,p(i,t)=B(i,t)/(B(i,t)+S(i,t)),即表示在时期t内买入股票i的基金占买卖股票i的所有基金的比例,p(t)为时期t内预期买入股票i的基金占买卖股票i的所有基金的比例,调整因子AF(i,t)=E[|p(i,t)-p(t)|],它是在没有羊群行为存在的零假设条件下的|B(i,t)/(B(i,t)+S(i,t))-p(t)|的期望值。因为B(i,t)是服从参数为p(t)的二项分布,所以调整因子AF如下:
问题:
这个涉及循环,每一个样本都要循环,还要嵌套,搞了半天也不会,只好求助大家了,用stata怎么编程呢?
给出的数据变量分别是季度tq、股票代码stk、买入B、卖出S、总交易T、均值P(t)
----------------------- copy starting from the next line -----------------------
- * Example generated by -dataex-. To install: ssc install dataex
- clear
- input float tq long stk int B byte S int T float m1
- 196 1 24 9 33 .5955285
- 196 2 29 18 47 .5955285
- 196 24 14 8 22 .5955285
- 196 63 18 14 32 .5955285
- 196 69 12 11 23 .5955285
- 196 157 9 8 17 .5955285
- 196 338 4 1 5 .5955285
- 196 402 7 3 10 .5955285
- 196 425 8 3 11 .5955285
- 196 538 4 2 6 .5955285
- 196 568 9 6 15 .5955285
- 196 623 2 4 6 .5955285
- 196 629 6 3 9 .5955285
- 196 651 15 19 34 .5955285
- 196 729 4 3 7 .5955285
- 196 792 8 6 14 .5955285
- 196 800 4 6 10 .5955285
- 196 858 6 3 9 .5955285
- 196 877 3 2 5 .5955285
- 196 895 11 1 12 .5955285
- 196 933 . 5 5 .5955285
- 196 983 6 1 7 .5955285
- 196 2007 1 4 5 .5955285
- 196 2022 1 4 5 .5955285
- 196 2024 20 23 43 .5955285
- 196 2028 1 4 5 .5955285
- 196 2202 15 7 22 .5955285
- 196 600000 62 35 97 .5955285
- 196 600005 8 2 10 .5955285
- 196 600009 2 6 8 .5955285
- 196 600015 3 7 10 .5955285
- 196 600016 25 6 31 .5955285
- 196 600019 7 3 10 .5955285
- 196 600028 11 7 18 .5955285
- 196 600030 66 37 103 .5955285
- 196 600031 7 4 11 .5955285
- 196 600036 47 40 87 .5955285
- 196 600048 25 11 36 .5955285
- 196 600050 14 2 16 .5955285
- 196 600089 14 25 39 .5955285
- 196 600276 5 10 15 .5955285
- 196 600309 6 7 13 .5955285
- 196 600315 . 5 5 .5955285
- 196 600325 8 8 16 .5955285
- 196 600383 3 9 12 .5955285
- 196 600395 5 1 6 .5955285
- 196 600415 2 9 11 .5955285
- 196 600518 2 3 5 .5955285
- 196 600519 22 24 46 .5955285
- 196 600547 5 8 13 .5955285
- 196 600550 7 4 11 .5955285
- 196 600582 1 5 6 .5955285
- 196 600583 11 8 19 .5955285
- 196 600585 9 6 15 .5955285
- 196 600664 3 3 6 .5955285
- 196 600694 5 3 8 .5955285
- 196 600739 7 6 13 .5955285
- 196 600795 4 1 5 .5955285
- 196 600816 5 . 5 .5955285
- 196 600859 4 2 6 .5955285
- 196 600875 1 9 10 .5955285
- 196 600895 1 7 8 .5955285
- 196 601006 7 . 7 .5955285
- 196 601088 11 8 19 .5955285
- 196 601166 30 15 45 .5955285
- 196 601169 19 2 21 .5955285
- 196 601186 14 1 15 .5955285
- 196 601318 78 50 128 .5955285
- 196 601328 17 4 21 .5955285
- 196 601398 17 8 25 .5955285
- 196 601601 11 1 12 .5955285
- 196 601628 20 4 24 .5955285
- 196 601939 7 3 10 .5955285
- 197 1 14 15 29 .6178108
- 197 2 22 28 50 .6178108
- 197 24 5 8 13 .6178108
- 197 63 12 2 14 .6178108
- 197 69 9 13 22 .6178108
- 197 157 5 2 7 .6178108
- 197 402 1 5 6 .6178108
- 197 425 6 4 10 .6178108
- 197 568 5 2 7 .6178108
- 197 651 21 4 25 .6178108
- 197 792 1 9 10 .6178108
- 197 858 3 3 6 .6178108
- 197 895 2 6 8 .6178108
- 197 983 6 8 14 .6178108
- 197 2007 5 . 5 .6178108
- 197 2024 29 1 30 .6178108
- 197 2202 6 . 6 .6178108
- 197 600000 106 10 116 .6178108
- 197 600015 4 5 9 .6178108
- 197 600016 19 11 30 .6178108
- 197 600019 5 5 10 .6178108
- 197 600028 5 2 7 .6178108
- 197 600030 30 27 57 .6178108
- 197 600036 51 33 84 .6178108
- 197 600048 19 13 32 .6178108
- 197 600050 9 3 12 .6178108
- 197 600089 6 2 8 .6178108
- 197 600104 2 3 5 .6178108
- 197 600276 4 1 5 .6178108
- 197 600315 5 . 5 .6178108
- 197 600325 4 9 13 .6178108
- 197 600383 9 1 10 .6178108
- 197 600415 8 . 8 .6178108
- 197 600519 19 14 33 .6178108
- 197 600550 2 4 6 .6178108
- 197 600583 11 . 11 .6178108
- 197 600585 1 5 6 .6178108
- 197 600694 1 5 6 .6178108
- 197 600739 3 2 5 .6178108
- 197 600875 5 2 7 .6178108
- 197 600900 3 7 10 .6178108
- 197 600970 5 . 5 .6178108
- 197 601006 6 2 8 .6178108
- 197 601088 8 3 11 .6178108
- 197 601166 36 31 67 .6178108
- 197 601169 6 10 16 .6178108
- 197 601186 2 3 5 .6178108
- 197 601318 72 58 130 .6178108
- 197 601328 16 7 23 .6178108
- 197 601398 15 10 25 .6178108
- 197 601601 4 8 12 .6178108
- 197 601628 4 4 8 .6178108
- 197 601939 9 2 11 .6178108
- 198 1 21 15 36 .6033316
- 198 2 21 27 48 .6033316
- 198 9 5 1 6 .6033316
- 198 24 6 4 10 .6033316
- 198 63 26 16 42 .6033316
- 198 69 17 15 32 .6033316
- 198 157 19 7 26 .6033316
- 198 338 11 7 18 .6033316
- 198 402 5 5 10 .6033316
- 198 425 6 6 12 .6033316
- 198 513 3 2 5 .6033316
- 198 527 14 8 22 .6033316
- 198 528 1 4 5 .6033316
- 198 538 5 . 5 .6033316
- 198 568 25 15 40 .6033316
- 198 623 4 5 9 .6033316
- 198 651 15 9 24 .6033316
- 198 792 6 1 7 .6033316
- 198 800 6 3 9 .6033316
- 198 858 2 3 5 .6033316
- 198 895 13 4 17 .6033316
- 198 898 5 2 7 .6033316
- 198 937 6 . 6 .6033316
- 198 983 20 11 31 .6033316
- 198 2001 6 2 8 .6033316
- 198 2007 . 5 5 .6033316
- 198 2024 25 11 36 .6033316
- 198 2038 3 2 5 .6033316
- 198 2142 9 1 10 .6033316
- 198 600000 30 60 90 .6033316
- 198 600005 6 . 6 .6033316
- 198 600015 7 4 11 .6033316
- 198 600016 61 31 92 .6033316
- 198 600019 3 3 6 .6033316
- 198 600028 14 10 24 .6033316
- 198 600030 22 21 43 .6033316
- 198 600031 20 10 30 .6033316
- 198 600036 108 30 138 .6033316
- 198 600048 29 16 45 .6033316
- 198 600050 22 6 28 .6033316
- 198 600089 7 3 10 .6033316
- 198 600104 17 7 24 .6033316
- 198 600196 5 4 9 .6033316
- 198 600216 5 1 6 .6033316
- 198 600276 7 2 9 .6033316
- 198 600309 9 1 10 .6033316
- 198 600315 6 1 7 .6033316
- 198 600325 7 2 9 .6033316
- 198 600348 10 3 13 .6033316
- 198 600362 3 2 5 .6033316
- 198 600383 5 10 15 .6033316
- 198 600406 5 . 5 .6033316
- 198 600415 5 4 9 .6033316
- 198 600517 5 3 8 .6033316
- 198 600519 32 32 64 .6033316
- 198 600550 5 3 8 .6033316
- 198 600583 2 3 5 .6033316
- 198 600585 11 6 17 .6033316
- 198 600596 3 2 5 .6033316
- 198 600600 2 3 5 .6033316
- 198 600660 7 . 7 .6033316
- 198 600664 6 2 8 .6033316
- 198 600690 8 1 9 .6033316
- 198 600694 3 5 8 .6033316
- 198 600739 4 2 6 .6033316
- 198 600785 1 4 5 .6033316
- 198 600837 5 . 5 .6033316
- 198 600875 10 5 15 .6033316
- 198 600887 4 3 7 .6033316
- 198 600900 4 3 7 .6033316
- 198 600970 2 3 5 .6033316
- 198 601006 10 4 14 .6033316
- 198 601009 12 1 13 .6033316
- 198 601088 25 12 37 .6033316
- 198 601166 62 63 125 .6033316
- 198 601169 36 26 62 .6033316
- 198 601318 83 82 165 .6033316
- 198 601328 35 21 56 .6033316
- 198 601390 2 5 7 .6033316
- 198 601398 14 10 24 .6033316
- 198 601601 13 12 25 .6033316
- 198 601628 11 9 20 .6033316
- 198 601666 3 4 7 .6033316
- 198 601699 4 1 5 .6033316
- 198 601939 13 9 22 .6033316
- 198 601988 4 1 5 .6033316
- 199 1 12 20 32 .3919874
- 199 2 4 11 15 .3919874
- 199 63 16 23 39 .3919874
- 199 69 3 6 9 .3919874
- 199 157 2 6 8 .3919874
- 199 338 2 5 7 .3919874
- 199 402 2 3 5 .3919874
- 199 425 3 10 13 .3919874
- 199 513 3 3 6 .3919874
- 199 527 8 5 13 .3919874
- 199 538 4 2 6 .3919874
- 199 568 9 20 29 .3919874
- 199 651 7 14 21 .3919874
- 199 800 2 4 6 .3919874
- 199 858 3 3 6 .3919874
- 199 895 3 8 11 .3919874
- 199 983 13 19 32 .3919874
- 199 2001 2 5 7 .3919874
- 199 2024 13 17 30 .3919874
- 199 2142 4 6 10 .3919874
- 199 600000 14 39 53 .3919874
- 199 600016 27 36 63 .3919874
- 199 600019 1 4 5 .3919874
- 199 600028 6 8 14 .3919874
- 199 600030 12 18 30 .3919874
- 199 600031 7 8 15 .3919874
- 199 600036 64 56 120 .3919874
- 199 600048 2 11 13 .3919874
- 199 600050 7 8 15 .3919874
- 199 600089 2 3 5 .3919874
- 199 600104 11 6 17 .3919874
- 199 600216 1 5 6 .3919874
- 199 600219 . 5 5 .3919874
- 199 600276 6 5 11 .3919874
- 199 600309 3 4 7 .3919874
- 199 600325 1 4 5 .3919874
- 199 600348 3 6 9 .3919874
- 199 600406 3 3 6 .3919874
- 199 600415 2 5 7 .3919874
- 199 600519 18 31 49 .3919874
- 199 600570 1 4 5 .3919874
- 199 600582 2 6 8 .3919874
- 199 600585 1 9 10 .3919874
- 199 600660 4 4 8 .3919874
- 199 600690 4 6 10 .3919874
- 199 600694 2 3 5 .3919874
- 199 600837 4 2 6 .3919874
- 199 600875 3 2 5 .3919874
- 199 600887 4 5 9 .3919874
- 199 601006 7 3 10 .3919874
- 199 601009 3 4 7 .3919874
- 199 601088 7 15 22 .3919874
- 199 601166 39 63 102 .3919874
- 199 601169 15 32 47 .3919874
- 199 601318 53 95 148 .3919874
- 199 601328 18 15 33 .3919874
- 199 601398 8 8 16 .3919874
- 199 601601 6 8 14 .3919874
- 199 601628 3 11 14 .3919874
- 199 601668 4 12 16 .3919874
- 199 601699 1 4 5 .3919874
- 199 601939 5 8 13 .3919874
- end
- format %tq tq
------------------ copy up to and including the previous line ------------------
我的命令这样的是错的,
[/CODE]
bys tq:n=_n
forval i=1/n{
forval k=0/T{
local sum=0
local P5=`k'/T
local c=comb(T,k)
local a=(`p5'-m1)*`c'*m1^k*(1-m1)^(T-k)
local sum=`sum'+`a'
}
}
[/CODE]
谢谢回答!