如何在样本里删除ST PT的公司

data indata;
  input stkcd date date7. status $;
  cards;
   1 1jan01 ST
   1 2jan01 NO
   1 3jan01 ST
   1 1jan02 NO
   1 2jan02 NO
   1 3dec02 NO
   1 1jan03 NO
   1 2jan03 ST
   1 3dec03 NO
   2 1jan01 NO
   2 2jan01 NO
   2 3jan01 NO
   2 1jan02 NO
   2 2jan02 NO
   2 3dec02 NO
   2 1jan03 NO
   2 2jan03 NO
   2 3dec03 NO
   ;
run;

* Data preparation;
data input1; set indata;
  if status="ST" then st_flag = 1; * Generate an indicator variable for ST companies on all trading days;
  else st_flag =0;

  year = year(date);               * generate a "year" variables, used to merge with annual accounting data;

* Generate annual "ST" indicator: 1 - ST, 0 - NOT ST;
* Creteria: if "ST" on one or more days, annual "ST" (st_annual) is labelled as "ST";
proc sql;
  create table input2 as
  select distinct stkcd, year,
      case
       when sum(st_flag) ge 1 then 1
           else 0
           end as st_annual
  from input1
  group by stkcd, year;
quit;

* Merge with accounting data;
......

11# BraveMadMan
呵呵，刚看到这个答复，非常感谢

学习了，我想着手动删吧，学这程序也太难了，崩溃

学习了，是不是说这支股票只要出现了ST是不是就样本里把这支股票全部删除？

suly 发表于 2010-7-13 22:15
如题。谢谢

啥信息