- data have;
- input date obs1 obs2 ;
- cards;
- 20150101 3 5
- 20150101 4 6
- 20150101 6 4
- 20150101 5 2
- 20150102 4 3
- 20150102 3 5
- 20150102 5 2
- 20151013 3 5
- 20151014 5 3
- ;
- run;
- data want(drop = obs2);
- set have;
- by date;
- if first.date then sum = 0;
- sum + obs2;
- if last.date;
- run;