Counting number of obs within by group based on the variable value

[windy]

Hi everyone, 

I have a problem with counting the number of observations within by group and based on the change in variable value. Let's me clarify it by the data set example:

I want to create a new variable - wanted - based on the number of values 0 and 1 in the variable indicator. The indicator values can change from 0 to 1 and vice versa. I want to count the number of each batch of value 0 or 1. The count need to be based on the by group (ID) as well. If I can add variables showing the start_time and end_time of each batch within by group, it would be awesome. 

ID	time	indicator	wanted	start_time	end_time
1	1	1	4	1	4
1	2	1	4	1	4
1	3	1	4	1	4
1	4	1	4	1	4
1	5	0	3	5	7
1	6	0	3	5	7
1	7	0	3	5	7
1	8	1	4	8	11
1	9	1	4	8	11
1	10	1	4	8	11
1	11	1	4	8	11
2	1	1	6	1	6
2	2	1	6	1	6
2	3	1	6	1	6
2	4	1	6	1	6
2	5	1	6	1	6
2	6	1	6	1	6
2	7	0	5	7	11
2	8	0	5	7	11
2	9	0	5	7	11
2	10	0	5	7	11
2	11	0	5	7	11
2	12	1	4	12	15
2	13	1	4	12	15
2	14	1	4	12	15
2	15	1	4	12	15

Thank you so much in advance for all your support. 

Kind regards, 

Windy. 

[seemiyah · Accepted solution]

Here's one approach 

data have ;
    input ID Time Indicator ;
    cards ;
1 1 1 
1 2 1 
1 3 1 
1 4 1 
1 5 0 
1 6 0 
1 7 0 
1 8 1 
1 9 1 
1 10 1 
1 11 1 
2 1 1 
2 2 1 
2 3 1 
2 4 1 
2 5 1 
2 6 1 
2 7 0 
2 8 0 
2 9 0 
2 10 0 
2 11 0 
2 12 1 
2 13 1 
2 14 1 
2 15 1
;
run ;

proc sort data=have ;
    by ID Time Indicator ;

data want ;
    do until(Last.Indicator) ;
        set have ;
        by Id Indicator notsorted;
        Wanted=sum(Wanted,1) ;
        if first.Indicator then Start_Time=Time ;
        if last.Indicator then End_Time=Time ;
    end ;

    do until(Last.Indicator) ;
        set Have ;
        by Id Indicator notsorted;
        output ;
    end ;
run ;

[windy]

Thank you so much for your help.

[Ksharp]

data have ;
    input ID Time Indicator ;
    cards ;
1 1 1 
1 2 1 
1 3 1 
1 4 1 
1 5 0 
1 6 0 
1 7 0 
1 8 1 
1 9 1 
1 10 1 
1 11 1 
2 1 1 
2 2 1 
2 3 1 
2 4 1 
2 5 1 
2 6 1 
2 7 0 
2 8 0 
2 9 0 
2 10 0 
2 11 0 
2 12 1 
2 13 1 
2 14 1 
2 15 1
;
run ;

data temp;
  set have ;
  by Id Indicator notsorted;
  if first.Indicator then group+1;
run;
proc sql;
create table want as
select *,count(*) as want,
 min(Time) as start_time,
 max(Time) as end_time
 from temp
  group by group;
quit;

[windy]

This approach is working perfectly as well. I wish that I can accept both solutions.