retain

[SAS_inquisitive]

Hello,

This example code is takne from this paper (https://www.pharmasug.org/proceedings/2013/TF/PharmaSUG-2013-TF12.pdf). I don' think we need to retain ldosdt variable.

DATA ds1a (keep=usubjid fdosdt ldosdt);
	set ipadmin;
	by usubjid startdt;
	retain fdosdt ldosdt;

	if first.usubjid then
		fdosdt = startdt;

	if last.usubjid then
		do;
			ldosdt = startdt;
			output;
		end;
run;

I tried to simulate the above with this program.

data test;
	input id $ x;
	cards;
a  1
a  2
a  3
;
run;

data want;
	set test;
	by id;
	retain f_;

	if first.id then
		f_=x;

	if last.id then
		do;
			l_=x;
			output;
		end;
run;

[art297 · Accepted solution]

You are correct .. you don't have to retain the 2nd variable. Doesn't hurt, but definitely not necessary.

Art, CEO, AnalystFinder.com

[SAS_inquisitive]

@art297 Thanks, Art.