topic I need help getting a difference between subsequent values on a list in SAS Programming

I need help getting a difference between subsequent values on a list

Xamius32 — Fri, 11 Jan 2013 23:55:13 GMT

So I need to see how many days have passed between observations.

So :

Person Date

A 1/1/12

A 1/5/12

A 1/7/12

B 4/5/12

B 4/9/12

B and so on

Basically, I want a column to the right that says X days have passed since last instance. I am thinking an array, but I am horrible at arrays.

Re: I need help getting a difference between subsequent values on a list

data_null__ — Sat, 12 Jan 2013 00:20:09 GMT

DIF function sounds about right.

data dif;
   input id:$1. date :mmddyy.; 
   format date date.; 
   cards; 
A 1/1/12
A  1/5/12
A  1/7/12
B 4/5/12
B 4/9/12
;;;;
   run; 
data dif2;
   set dif;
   by id;
   dif = dif(date);
   if first.id then dif=.F; 
   run; 