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;
You are correct .. you don't have to retain the 2nd variable. Doesn't hurt, but definitely not necessary.
Art, CEO, AnalystFinder.com
You are correct .. you don't have to retain the 2nd variable. Doesn't hurt, but definitely not necessary.
Art, CEO, AnalystFinder.com
@art297 Thanks, Art.
Join us for SAS Innovate April 16-19 at the Aria in Las Vegas. Bring the team and save big with our group pricing for a limited time only.
Pre-conference courses and tutorials are filling up fast and are always a sellout. Register today to reserve your seat.
Learn how use the CAT functions in SAS to join values from multiple variables into a single value.
Find more tutorials on the SAS Users YouTube channel.