topic Re: Need previous data if it is different from the last data in SAS Programming

Need previous data if it is different from the last data

india2016 — Fri, 12 Oct 2018 06:00:37 GMT

Hi All,

Need small help. I have data like below

A	Unique_ID	Version
Murder	1	1
Theft	1	2
dacoity	1	3
Murder	2	1
Murder	2	2

I want an output like below:

Unique ID	Previous_A	Present_A
1	Theft	Dacoity
2	Murder	Murder

Basically if for Unique_ID there is a version. For the last version and before last version if Column "A" is different then I need 2 column to be created Previous_A and Present_A. Previous A will hold the 2nd last version value and Present A will hold the last version value.

Re: Need previous data if it is different from the last data

PeterClemmensen — Fri, 12 Oct 2018 06:19:11 GMT

data have;
input A $ Unique_ID Version;
datalines;
Murder 1 1
Theft 1 2
dacoity 1 3
Murder 2 1
Murder 2 2
;

data want;
   set have; 
   by Unique_ID Version; 
   lagA=lag1(A);
   if last.Unique_ID then do;
      Previous_A=lagA;
      Present_A=A;
      output;
   end;
   keep Unique_ID Previous_A Present_A;
run;

Re: Need previous data if it is different from the last data

india2016 — Fri, 12 Oct 2018 07:58:50 GMT

Thanks @PeterClemmensen.