Question

我想使用SAS中的proc SQL计算两个平均值，一个在特定日期之前的行上，另一个在特定日期之后的行上。目前，我分两步进行操作，然后合并。有没有办法一步一步做到这一点？谢谢。

proc SQL;

create table temp.consensus_forecast_1 as 

select distinct gvkey, datadate, avg(meanest) as avg_before from temp.consensus_forecast

where cal_date < fdate

group by gvkey, fdate;

quit;


proc SQL;

create table temp.consensus_forecast_2 as 

select distinct gvkey, datadate, avg(meanest) as avg_after from temp.consensus_forecast

where cal_date > fdate

group by gvkey, fdate;

quit;

Answer 1

proc sql;
  create table temp.consensus_forecast as
  select gvkey, datadate,
    avg(case when cal_date < fdate then meanest else . end) as avg_before,
    avg(case when cal_date >= fdate then meanest else . end) as avg_after
  from temp.consensus_forecast
  group by gvkey, fdate;
quit;

不需要DISTINCT子句，GROUP BY将解决这个问题。使用PROC Summary也很容易

Answer 2

使用SAS用true表示1，用false表示0的事实：

proc SQL;
    create table temp.consensus_forecast as 
    select distinct gvkey, datadate, 
        sum(meanest * (cal_date < fdate)) / sum(cal_date < fdate) as avg_before,
        sum(meanest * (cal_date > fdate)) / sum(cal_date > fdate) as avg_after
    from temp.consensus_forecast
    where 
    group by gvkey, fdate;
quit;

给出与您的代码相同的结果。

请注意，这可能是错误的，因为您忽略了cal_date = fdate的情况。

Answer 3

选择任何内容，将avg（日期>截止时的情况，然后myValue否则为null结束）作为avg_aft，avg（当日期<=截止时，然后myValue的情况下，否则null结束）作为avg_bef 来自...等。

proc sql：一步根据不同条件计算多个摘要统计信息

3 个答案: