Count number of consecutives occurences

[Amine_Khemiri]

Hello there,

I would appreciate if you could help me to calculate the number of consecutives occurences.

Here is an example

Have

ID	Group
1	0
2	1
3	0
4	1
5	1
6	0
7	0

Want

ID	Group	Count
1	0	0
2	1	1
3	0	0
4	1	2
5	1	2
6	0	0
7	0	0

Thanks in advance!

[Astounding · Accepted solution]

Here's an approach:

data want;
   counter = 0;
   do until (last.group);
      set have;
      by group notsorted;
      counter + 1;
   end;
   do until (last.group);
      set have;
      by group notsorted;
      if group = 0 then count = 0;
      else count = counter;
      output;
   end;
   drop counter;
run;

It's untested code, so you will have to try it to see if it needs any adjustments.

[Amine_Khemiri]

Thanks a lot! I tested it and it works fine.