Date:         Tue, 6 Feb 2007 08:59:04 -0500
Reply-To:     Don Henderson <donaldjhenderson@HOTMAIL.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
Comments:     RFC822 error: <W> MESSAGE-ID field duplicated. Last occurrence
              was retained.
From:         Don Henderson <donaldjhenderson@HOTMAIL.COM>
Subject:      Re: counter variable
Comments: To: Peter Crawford <peter.crawford@BLUEYONDER.CO.UK>
In-Reply-To:  <200702061254.l16BkjvU016919@malibu.cc.uga.edu>
Content-Type: text/plain; charset="us-ascii"

As usual, Peter's suggestions are spot on.

However, I have another suggestion - use the data step debugger to step thru
the logic so you can see where the problem is. Just add /debug to the end of
your data statement, e.g.,

data count/debug;
 /* rest of your step 8/
run;

In case you are not familiar with the debugger, check out:

http://www2.sas.com/proceedings/sugi25/25/btu/25p052.pdf

Found this paper using a quick search at support.sas.com. Other SAS-L folks
might have other suggestions for doc on the data step debugger.

HTH,
-don h

-----Original Message-----
From: SAS(r) Discussion [mailto:SAS-L@LISTSERV.UGA.EDU] On Behalf Of Peter
Crawford
Sent: Tuesday, February 06, 2007 7:55 AM
To: SAS-L@LISTSERV.UGA.EDU
Subject: Re: counter variable

Simon

with one obvious typing error (marked) in the message, are there more that I
have not seen?

If count is not correct, check that you don't have a variable named count,
in the dataset you are reading

Why not simplify this to something like

data count;
  set a( drop=count);
   by id;
  if first.id then count= 0 ;
  count+1;
  last_id= last.id ;
run;


Peter Crawford

On Tue, 6 Feb 2007 03:59:46 -0500, Simon Chang <syner@PCHOME.COM.TW> wrote:

>Hellow:
>
>I got a problem in counting as well.
>I had no idea about why this would happen!
>Could any body help me!!
>
>Thanks in advance!
>
>Simon
>
>Here is my SAS code below.
>
>(A)
>proc sort data=a; by id;
>Data count;
>  set a;
>    by id;
>   retain count 0;
>   if first.id then count=0;
>   count=count+1;
>   if last.count then last_id=1; else last_id=0;
.......^^^^^^^^^ ........

count is not a by variable, so    last.count    is a syntax error
>run;
>
>OR:
>(B)
>data count;
>  set a;
>    count+1;
>   by id;
>    if first.id then count=1;
>    if last.id  then last_id=1; else last_id=0; run;
>
>
>(C)Result:
>(the numbers with * are completly wrong!!!)
>ID    count    last_id
>A       1         0
>A       2         0
>A       2*        1
>B       1         0
>B       2         1
>C       1         0
>C       3*        1