Simply Counter

[Bernardita]

Hi,

I simply would like to set a new Var "Counter" thats count to 12 (in the example below to 3) by the ID. I mean within the same ID, it can be hundred of them, I would like to count the rows by 12 (equivalent to months), each time gets to 12 then reset to 1 again until 12, to the end of the rows until ID changes. So this counter repeat itself in the same way for each new ID.

I imagine is simply, my problem is I am only learning!!! Thank you a lot for your help. Bernardita

ID	Counter
A	1
A	2
A	3
A	1
A	2
A	3
A	1
A	2
A	3
A	1
B	1
B	2
B	3
B	1
B	2
B	3
B	1
B	2
B	3
B	1
B	2
C	1
C	2
C	3
C	1
C	2
C	3
C	1
C	2
C	3
C	1
C	2

[RW9 · Accepted solution]

Hi,

Yep, pretty simple - I will  go by your given example below:

data want;
  set have;
  by id;
  retain counter;
  if first.id or counter > 3 then counter=0;
  else counter=counter+1;
run;

[Bernardita]

This is great!!! Thank you a lot!