按照中位数定义写了一段sql语句求中位数的程序，不过和proc mean比起来复杂太多
如果总数为奇数，则中位数的第（n+1）/2个数
如果总数为偶数，则中位数等于第n/2个数与第n/2+1个数的均值


proc sort data=a1 out=a1;
by id b;
run;
data a1;
set a1;
by id b;
if first.id then n1=1;
else n1+1;
run;
proc sql;
create table a2 as
select distinct id,mean(b) as mb
from (select * from a1 group by id having 0<=n1-max(n1)/2<=1) group by id;
quit;

写的很不错的sql，学习一下

比较复杂啊 新手飘过

学习

非常好用！

请问语句中的b代表什么？