topic question on "Finding the First or Last Observation in a Group" in SAS Procedures

question on "Finding the First or Last Observation in a Group"

helensh — Sat, 31 Dec 2011 16:28:21 GMT

I follow the steps provided in the following website http://support.sas.com/documentation/cdl/en/basess/58133/HTML/default/viewer.htm#a001349233.htm.

proc sort data=Gta2 Out=Gta3;
by Agmtcd;
run;

data sub_Gta3;
set Gta3;
by Agmtcd;
run;

data sub_Gta3;
set Gta3;
FirstAgmtcd=first.Agmtcd;
LastAgmtcd=last.Agmtcd;
run;

However, SAS says the variables "first.Agmtcd" and "last.Agmtcd" are not initialized. The format of Agmtcd is $10. Does anybody know what's wrong with my code?

Thanks a lot!

question on "Finding the First or Last Observation in a Group"

art297 — Sat, 31 Dec 2011 16:33:52 GMT

You have 3 datasteps when you should only have 2. The first. and last. variables are only available when a by statement is present within the SAME datastep. Thus, try it with:

proc sort data=Gta2 Out=Gta3;
by Agmtcd;
run;

data sub_Gta3;
set Gta3;
by Agmtcd;FirstAgmtcd=first.Agmtcd;

LastAgmtcd=last.Agmtcd;
run;

question on "Finding the First or Last Observation in a Group"

helensh — Mon, 02 Jan 2012 03:06:38 GMT

It works. Thanks a lot!!!