lqwoailuo 发表于 2013-12-10 16:20 
data a;
input d1 d2 d3;
cards;
data a;
input d1 d2 d3;
cards;
1 2 7
2 3 .
3 . 4
;
run;
proc sort data=a;
by d1;
run;
proc sql ;
create table b as
select d1, mean(d2) as d2, mean(d3) as d3
from a;
quit;
data c;
update b a ;
by d1;
run;