Date:         Thu, 5 Feb 2004 11:48:30 -0500
Reply-To:     Howard Schreier <Howard_Schreier@ITA.DOC.GOV>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Howard Schreier <Howard_Schreier@ITA.DOC.GOV>
Subject:      Re: create a new variable that indicate a change

Try this.

   data with_changes;
   do i = 1 by 1 until(last.id); drop i;
      set test;
      by id;
      if i=1 then start = amount; drop start;
      end;
   change_in_amount = amount - start;
   run;

Result:

                           change_
 Obs      ID     AMOUNT    in_amount

  1     10001     3000        1000
  2     10002     3000         500
  3     10003     1000           0

By including a DATA step and data lines to load the test data, you made it
very easy to work with this problem.

If you had also included a corresponding example of output, there would be
less variation in the responses based on different interpretations.

On Thu, 5 Feb 2004 10:35:54 -0500, Jesper Nyholm
<jesper_nyholm@POST.TELE.DK> wrote:

>/***
>Hi
>Can anybody tell me how to create a new variable that indicate a  change
>in  amount for every id?
>***/
>DATA TEST;
>   INPUT ID 1-5 AMOUNT 7-11;
>DATALINES;
>10001 2000
>10001 2000
>10001 3000
>10002 2500
>10002 3000
>10003 1000
>10003 1000
>10003 1000
>10003 2000
>10003 1000
>;