Add a cumulative count that resets when value = 0

[sweetgorgor]

Hi, this is probably an easy question, am looking to add a cumulative  # of days a student made a mistake, and this resets to 0 when the student stop making mistakes. I have created a simple table to further illustrate my needs.

Date	Mistake_Flg	Days_Mistake_Streak
1-Jan	0	0
2-Jan	0	0
3-Jan	1	1
4-Jan	1	2
5-Jan	1	3
6-Jan	0	0
7-Jan	0	0
8-Jan	1	1
9-Jan	1	2
10-Jan	0	0

Where "Days_mistake_streak" is what I'm trying to derive.

Thanks!

[art297 · Accepted solution]

You could use something like:

data want;

  set have;

  retain Days_Mistake_Streak;

  Days_Mistake_Streak=ifn(Mistake_Flg eq 0,0,Days_Mistake_Streak+1);

run;

[sweetgorgor]

worked like a charm, thanks so much Arthur!