Date:         Mon, 7 Sep 1998 21:13:07 +0100
Reply-To:     roland.rashleigh-berry@virgin.net
Sender:       "SAS(r) Discussion" <SAS-L@UGA.CC.UGA.EDU>
From:         Roland <roland.rashleigh-berry@VIRGIN.NET>
Organization: Wogs at Cause
Subject:      Re: I'm an idiot, please help! How to create cummulative variable.
Content-Type: text/plain; charset=us-ascii

data cum;
  retain arcum 0;
  set whatever;
  arcum=arcum+armean;
run;
 
Roland
 
 
 
Edward Kohl wrote:
>
> O.K. I'm a beginner, but that's still no excuse for not
> being able to do the most basic SAS operation!!  Please
> flame me when you reply.
>
> I have a varaible, ARMEAN, with 201 observations and all I
> want to do is create a new variable, ARCUM, whose value is
> the sum of all previous ARMEANS values.  In other words, I
> want a cumulative value of all previous ARMEANS for each
> iteration.
>
> So it would look something like this:
>
> ARMEAN        ARCUM
> 1                            1
> 2                            3
> 3                            6
> 4                            10
>
> Sounds easy enough, right?  Well, I tried doing this,
>
> ARCUM = ARMEAN + lag(ARCUM)
>
> but all I got was a column of missing values.  I've also
> tried the 'retain' command to set an intitial value for
> ARCUM but that didn't work either, or I didn't use it
> correctly.  I've tried other things as well but I won't
> repeat them here because you'll just laugh at me.
>
> I know I'm missing something completely obvious, but I'd
> rather  embarrass myself on a newsgroup than risk being
> dragged away to a mental institution?  Thanks.
>
> Edward