Finding last observation

[ari]

Have:
ID	v1	v2	v3
1	-3	a	a
1	-2	b	b
1	-1	c	b
1	1	d	b
2	-20	a	a
2	-6	b	b
2	-3	c	b
2	-2	d	b
3	1	a	a
want:
ID	v1	v2	v3
1	1	d	b
2	-2	d	b
3	1	a	a

I am trying to find one unique observation per id.   v1 ranges from 1 to -20. I am trying  to output  the highest and unique value possible for v1. 

[Kurt_Bremser]

Very easy.

proc sort data=have;
by id v1;
run;

data want;
set have;
by id;
if last.id;
run;

[LinusH]

Is the ID and v1 combination unique?

If so, use SQL with group by ID having max(v1) = v1.