如何根据x取值的频率大小排序后取出为宏变量的值

1. data aaa;
   
2. input x$ y;
   
3. cards;
   
4. aa 12
   
5. aa 13
   
6. cc 14
   
7. cc 15
   
8. cc 16
   
9. dd 18

复制代码

根据x取值的频率大小排序后取出为宏变量的值，此例应为ccc aa dd，谢谢！

proc freq order=freq;
table x/out=bbb(keep=x);
run;

proc sql;
   select x into:seq separated by ' ' from bbb;
   quit;
%put &seq;

farmman60 发表于 2014-3-3 06:29
proc freq order=freq;
table x/out=bbb(keep=x);
run;

不用proc freq过程，能否就用proc sql 实现？

proc sql;
  select x into:seq separated by ' ' from (select x,count(x) as num from aaa group by x) order by num desc;
  quit;

  %put &seq;