topic Re: GET MIN and MAX date datasetp in SAS Procedures

GET MIN and MAX date datasetp

Almighty — Mon, 24 Feb 2014 20:36:33 GMT

I am trying to get MIN date and MAX date; I can do with Proc Sql, but was wondering is there a way to do with DATA STEP

Thanks

example below;

DATA HAVE

SUBJID	VISITNUM	VISIT	FIRSTDATE	LASTDATE
1	20	BASELINE (RAW)	13-May-10	14-Jun-10
1	30	MONTH 1	15-Jun-10	12-Aug-10
1	40	MONTH 3	13-Aug-10	11-Nov-10
1	50	MONTH 6	12-Nov-10	12-May-11
1	70	MONTH 12	13-May-11	10-Nov-11
1	90	MONTH 18	11-Nov-11	8-May-12
1	110	MONTH 24	9-May-12	13-Nov-12
1	130	MONTH 30	14-Nov-12	21-May-13
1	150	MONTH 36	22-May-13	1-Aug-13

DATA NEED:

SUBJID	VISITNUM	VISIT	FIRSTDATE	LASTDATE	MIN FIRSTDATE	MAX LASTDATE
1	20	BASELINE (RAW)	13-May-10	14-Jun-10	13-May-10	1-Aug-13
1	30	MONTH 1	15-Jun-10	12-Aug-10	13-May-10	1-Aug-13
1	40	MONTH 3	13-Aug-10	11-Nov-10	13-May-10	1-Aug-13
1	50	MONTH 6	12-Nov-10	12-May-11	13-May-10	1-Aug-13
1	70	MONTH 12	13-May-11	10-Nov-11	13-May-10	1-Aug-13
1	90	MONTH 18	11-Nov-11	8-May-12	13-May-10	1-Aug-13
1	110	MONTH 24	9-May-12	13-Nov-12	13-May-10	1-Aug-13
1	130	MONTH 30	14-Nov-12	21-May-13	13-May-10	1-Aug-13
1	150	MONTH 36	22-May-13	1-Aug-13	13-May-10	1-Aug-13

SUBJID	MIN FIRSTDATE	MAX LASTDATE
1	13-May-10	1-Aug-13

Re: GET MIN and MAX date datasetp

LinusH — Mon, 24 Feb 2014 20:47:43 GMT

Yes you can, but why? SQL is much easier to code.

With the data step use retain.

Re: GET MIN and MAX date datasetp

art297 — Mon, 24 Feb 2014 21:03:22 GMT

You can do it fairly easily using a DOW loop. e.g.:

data need;

do until (last.subjid);

set have;

by subjid;

min_firstdate=min(min_firstdate,firstdate);

max_lastdate=max(max_lastdate,lastdate);

end;

format min_firstdate max_lastdate date9.;

do until (last.subjid);

set have;

by subjid;

output;

end;

run;

Re: GET MIN and MAX date datasetp

Almighty — Thu, 27 Feb 2014 14:25:58 GMT

Thanks Arthur. It worked.

Best

Re: GET MIN and MAX date datasetp

AjayKant — Thu, 27 Feb 2014 16:49:49 GMT

Hi Arthur .

The above result is great but how to get only single observation as per distinct subjid ;

Thank in advance .

Re: GET MIN and MAX date datasetp

Reeza — Thu, 27 Feb 2014 17:46:53 GMT

Consider only the first part of Art's solution

Re: GET MIN and MAX date datasetp

AjayKant — Thu, 27 Feb 2014 18:04:14 GMT

thanks..

Re: GET MIN and MAX date datasetp

art297 — Thu, 27 Feb 2014 18:48:05 GMT

Ajay,

Like Fareeza said, just consider the first part. However, add an output statement and you'll probably want to drop some variables. e.g.:

data need (drop=VISITNUM VISIT FIRSTDATE LASTDATE);

do until (last.subjid);

set have;

by subjid;

min_firstdate=min(min_firstdate,firstdate);

max_lastdate=max(max_lastdate,lastdate);

if last.subjid then output;

end;

format min_firstdate max_lastdate date9.;

run;