Date:         Thu, 5 Feb 2004 10:57:25 -0500
Reply-To:     "DePuy, Venita" <depuy001@DCRI.DUKE.EDU>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         "DePuy, Venita" <depuy001@DCRI.DUKE.EDU>
Subject:      Re: create a new variable that indicate a change
Comments: To: Jesper Nyholm <jesper_nyholm@POST.TELE.DK>
Content-Type: text/plain

This creates diff as a 0/1 variable for whether a difference exists between
the current line and the previous line.  It's missing if the previous line
had a different id.
HTH
Venita


data test;
        input id amount @@;
        lag_amt = lag(amount);
        lag_id = lag(id);
        if lag_id ne id then lag_amt = .;
        diff = lag_amt - amount;
        if diff ne 0 and diff ne . then diff = 1;
        drop lag_id lag_amt;
        cards;
        10001 2000      10001 2000      10001 3000      10002 2500
10002 3000      10003 1000
        10003 1000      10003 1000      10003 2000      10003 1000
        ;
proc print;run;



> ----------
> From:         Jesper Nyholm[SMTP:jesper_nyholm@POST.TELE.DK]
> Reply To:     Jesper Nyholm
> Sent:         Thursday, February 05, 2004 10:35 AM
> To:   SAS-L@LISTSERV.UGA.EDU
> Subject:      create a new variable that indicate a change
>
> /***
> 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
> ;
>