求助:如何填入空缺的数据?
有下列变量:
data A;
input dm sj1 sj2 kc;
cards;
1 21063 21063 201
1 21062 21063 195
1 21060 21063 100
2 21063 21063 0
2 21061 21063 100
2 21060 21063 132
3 21062 21063 111
3 21061 21063 100
3 21060 21063 99
;
run;
data b;
set a;
by dm;
if first.dm and sj1=sj2 and kc>0 then ratio=1;
run;
请教:如何将满足 if first.dm and sj1=sj2 and kc>0 条件的dm=1下面都添上1。 不满足条件的为 ratio=.
谢谢!!