exclude conditional records

[KalaBhairava]

Hi All,

I want records that are 0 before 1 and should not delete 0 after 1, how can I proceed?

Please check below data.

sub	dt
1	3/8/2022	0
1	3/9/2022	0
1	3/10/2022	1
1	3/11/2022	1
1	3/12/2022	0

[PeterClemmensen]

Do you want to keep or delete records with 0 before 1?

Do you want this logic to work by ID (sub) ?

[KalaBhairava]

either way, delete or flagging both are fine

[PeterClemmensen · Accepted solution]

I think this is what you want. 

I added an extra sub to make it suitable for by group processing.

data have;
input sub dt :mmddyy10. dummy;
format dt mmddyy10.;
datalines; 
1 3/8/2022  0
1 3/9/2022  0
1 3/10/2022 1
1 3/11/2022 1
1 3/12/2022 0
2 3/8/2022  0
2 3/9/2022  0
2 3/10/2022 1
2 3/11/2022 1
2 3/12/2022 0
;

data want;
   set have;
   by sub;
   if first.sub then _iorc_ = 0;
   if dummy then _iorc_ = 1;
   if _iorc_;
run;

Result

sub  dt          dummy
1    03/10/2022  1 
1    03/11/2022  1 
1    03/12/2022  0 
2    03/10/2022  1 
2    03/11/2022  1 
2    03/12/2022  0 

[KalaBhairava]

Thank you very much and it's working well.

[PeterClemmensen]

Anytime 🙂

[KalaBhairava]

Can you give me code to flags those records with 0 before 1?