topic Re: output observation at each change of occurance for 0, 1 in SAS Programming

output observation at each change of occurance for 0, 1

jenim514 — Sat, 13 Jul 2019 20:01:33 GMT

Hi all,

I have a data set with coded values 0 and 1 that are sorted by subject and date. Each time the occurrence happens, coded 1. When stops, coded 0. If occurrence happens again, then 1 etc. I want to output the observation by subject at each change of occurrence (1, 0, back to 1 etc).

Any ideas how I can set this up?

Subject	Response	Date	Wanted
123	1	10-May-18	X
123	1	22-Jun-18
123	0	30-Jul-18	X
123	1	12-Sep-18	X
125	1	15-Oct-18	X
125	1	16-Oct-18
125	1	15-Nov-18
125	0	1-Dec-18	X
125	0	20-Dec-18

Re: output observation at each change of occurance for 0, 1

Tom — Sat, 13 Jul 2019 20:03:22 GMT

Use the NOTSORTED keyword on your BY statement.

data want ;
  set have;
  by subject response notsorted;
  if first.response;
run;

Re: output observation at each change of occurance for 0, 1

singhsahab — Sun, 14 Jul 2019 08:39:09 GMT

If data sorted by subject variable :

DATA WANT (drop=x);
SET HAVE;
BY SUBJECT;
X=IFN(RESPONSE EQ LAG(Response),0,1);
IF X;
RUN;

Thanks

🙂

Re: output observation at each change of occurance for 0, 1

Tom — Sun, 14 Jul 2019 14:36:36 GMT

That will not work if two adjacent subjects happen to have the same value of RESPONSE.

Re: output observation at each change of occurance for 0, 1

jenim514 — Mon, 15 Jul 2019 16:30:03 GMT

@Tom thank you!