Create a count variable per ID

[ANKH1]

This is the dataset we have:

data have;
input ID age;
datalines;
1	131
1	0
1	0
2	22
2	76
3	0

3	48
3	48
3	3
;
run;

How do you create a variable that counts how many times the variable "age" has appeared up until that age. This means that the same ID can have multiple ages. The output should look like this:

data want;
input ID count_events;
datalines;
a1	131	1
a1	0	2
a1	0	3
b2	22	1
b2	76	2
c4	0	1
c4	48	2
c4	48	3
c4	3	4
;
run;

[Reeza · Accepted solution]

That looks like a basic counter.

data want;
set have;
by ID;
if first.id then count_events=0;
count_events+1;
run;

Note your want data set does not match the have and is missing a variable. Please ensure you test the code you post.

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@ANKH1 wrote:

This is the dataset we have:

data have;
input ID age;
datalines;
1	131
1	0
1	0
2	22
2	76
3	0

3	48
3	48
3	3
;
run;

How do you create a variable that counts how many times the variable "age" has appeared up until that age. This means that the same ID can have multiple ages. The output should look like this:

data want;
input ID count_events;
datalines;
a1	131	1
a1	0	2
a1	0	3
b2	22	1
b2	76	2
c4	0	1
c4	48	2
c4	48	3
c4	3	4
;
run;

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