Create seq for each group depend on Ind_Change

[Ronein]

Hello

Lets say I want to create a seq by group by the following way.

For each customer seq get same number until there is a change (Ind_change=1)

What is the way to create want data set?

data have;
input CustID Ind_Change;
cards;
1 0
1 0
1 0
1 0
1 0
1 0
1 0
1 0
1 0
1 0
1 0
1 0
2 0
2 0
2 1
2 0
2 0
2 0
2 0
2 0
2 0
2 0
2 0
2 0
3 0
3 0
3 1
3 0
3 1
3 0
3 0
3 0
3 0
3 0
3 0
3 0
4 1
4 0
4 0
4 0
4 0
4 0
4 0
4 0
4 0
4 0
4 0
4 0
;
Run;

data want;
input CustID Ind_Change seq;
cards;
1 0 1
1 0 1
1 0 1
1 0 1
1 0 1
1 0 1
1 0 1
1 0 1
1 0 1
1 0 1
1 0 1
1 0 1
2 0 1
2 0 1
2 1 1
2 0 1
2 0 1
2 0 1
2 0 1
2 0 1
2 0 1
2 0 1
2 0 1
2 0 1
3 0 1
3 0 1
3 1 2
3 0 2
3 1 3
3 0 3
3 0 3
3 0 3
3 0 3
3 0 3
3 0 3
3 0 3
4 1 1
4 0 1
4 0 1
4 0 1
4 0 1
4 0 1
4 0 1
4 0 1
4 0 1
4 0 1
4 0 1
4 0 1
;
Run;

[Ksharp · Accepted solution]

I think it is easy for you ,isn't it ? Since you are using sas for so many years.

data have;
input CustID Ind_Change;
cards;
1 0
1 0
1 0
1 0
1 0
1 0
1 0
1 0
1 0
1 0
1 0
1 0
2 0
2 0
2 1
2 0
2 0
2 0
2 0
2 0
2 0
2 0
2 0
2 0
3 0
3 0
3 1
3 0
3 1
3 0
3 0
3 0
3 0
3 0
3 0
3 0
4 1
4 0
4 0
4 0
4 0
4 0
4 0
4 0
4 0
4 0
4 0
4 0
;
Run;
data want;
 set have;
 by CustID;
 if first.CustID then want=0;
 if first.CustID or Ind_Change=1 then want+1;
run;