Date:         Wed, 20 Dec 2000 11:20:17 -0600
Reply-To:     JGerstle@SW.UA.EDU
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         John Gerstle <JGerstle@SW.UA.EDU>
Subject:      Coding diads - simple problem
Content-type: text/plain; charset=US-ASCII

Fellow SAS-L'ers,
        I've got a quick problem that has me stumped.  I want to code
each pair of ptid-staffid parings uniquely.  A simple numeric coding
will work.  Below is my most recent attempt:

proc sort data care_baseline; by ptid staffid; run;

data care_phase2; set care_baseline;
        by ptid staffid;
        if first.ptid and first.staffid then diad + 1;
        run;
        proc print; run;

The output file has diad increasing from the
first observation on but seems to only be
counting each unique ptid and not the pairing
that I want.  I also tried :

        if first.ptid and last.staffid then diad + 1;

but that didn't do it either.  What am I missing
here?

        Thanks for any insight....John


John Gerstle
Program Analyst, Sr.
Applied Gerontology Program
University of Alabama