Date:         Tue, 19 Oct 2010 20:00:48 -0400
Reply-To:     Nat Wooding <nathani@VERIZON.NET>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Nat Wooding <nathani@VERIZON.NET>
Subject:      Re: Hash or No-Hash solution to my problem?
Comments: To: Raghav Adimulam <raghavadimulam@WESTAT.COM>
In-Reply-To:  <201010192242.o9JH5kER012853@willow.cc.uga.edu>
Content-Type: text/plain; charset="us-ascii"

This is not as slick as the SQL solution but for those who do not do SQL, it
is an alternative.

Nat Wooding

Data NOHash;
input MRN $3.  DateDiff;
cards;
001 500
001 400
001 300
001 200
001 100
001 0
002 500
002 400
002 300
002 200
002 100
003 700
003 300
003 200
003 50
;
Data NoHash;
set nohash;
by mrn;
if first.mrn then count=0;
count+1;
run;

Proc Transpose data=nohash out = nohash (drop = _name_ ) Prefix = Col;
by mrn;
id count;
var DateDiff;
Run;

Data NoHash;
set nohash;
Keep MRN DateDiff;
Array A col: ;
MinDiff = Min( of col: );
Do _I_ = 1 to Dim(a) ;
DateDiff = A(_I_);
if Datediff = . then return;
if abs( MinDiff - DateDiff) lt 365 then output;
end;

Run;

-----Original Message-----
From: SAS(r) Discussion [mailto:SAS-L@LISTSERV.UGA.EDU] On Behalf Of Raghav
Adimulam
Sent: Tuesday, October 19, 2010 6:43 PM
To: SAS-L@LISTSERV.UGA.EDU
Subject: Hash or No-Hash solution to my problem?

Hello SAS-Lers,

Here is the simplified version of my problem, i.e. without the unnecessary
fields and misc data. I have a dataset with 2 fields that is sorted on MRN
and DateDiff as shown below.

MRN DateDiff
001 500
001 400
001 300
001 200
001 100
001 0

002 500
002 400
002 300
002 200
002 100

003 700
003 300
003 200
003 50

How can I accomplish a task so that I can keep only the records that fall
within 365 days of the lowest DateDiff for that MRN??

In other words, MRN 001 has qualifying records <=0+365
MRN 002 has qualifying records <=100+365 (=465)
MRN 003 has qualifying records <=50+365 (=415)

Thus the final dataset should be..

MRN DateDiff
001 300
001 200
001 100
001 0

002 400
002 300
002 200
002 100

003 300
003 200
003 50

Thanks for your answers in advance!

-Raghav