Count cumulative by groups

[ywon111]

Hi, I have below table that I want to count by Obj and if same date then this can be ignored as same count. If date is zero then want is zero.

Obj	Dates	Want
a	1/01/2020	1
a	1/01/2020	1
a	2/01/2020	2
a	3/01/2020	3
b	.	0

Thanks in advance

[Kurt_Bremser]

data want;
set have;
by obj;
if first.obj then want = 0;
if dates ne . and (obj ne lag(obj) or dates ne lag(dates)) then want + 1;
run;

[s_lassen]

Assuming that your data is sorted by OBJ and DATE (meaning that missing dates come first) this should do it

data want;
  set have;
  by obj date;
  if first.obj then count=not missing(date);
  else count+first.date;
run;