Date:         Wed, 28 Jan 2004 14:26:27 GMT
Reply-To:     julierog@ix.netcom.com
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Roger Lustig <trovato@VERIZON.NET>
Subject:      Re: count & count(distinct)
Content-Type: text/plain; charset=us-ascii; format=flowed

Dear David:
You've already seen the simple solution--PROC SQL.  Here's a slightly
more subtle one, which assumes that the input file is sorted by NAME and
VALUE, but which runs like the wind.

data counts (drop=value);
count=0;
count_distinct=0;
do until (last.name);
   set indata(keep=name value);
   by name value;
   count + 1;
   if first.value
     then count_distinct + 1;
   end;
run;

By the way, when you can explain *why* this works, and what each
statement does, you will no longer be a newbie to SAS.

Best,
Roger

David Chang wrote:

> Hi, I am a newbie to SAS, and I am wondering whether SAS can do something
> like sql's count and count(distinct) against SAS data sets. Here is an
> example of what I am trying to do:
>
> Input data set: indata
> name    value
> ====    ====
> john        4
> john        3
> tom        2
> tom        2
> tom        2
>
> output data set: outdata
> name    count    count_distinct
> ====    ====    ==========
> john       2            2
> tom        3            1
>
>
> Could anyone help me with this? A sample code would be greatly appreciated
> !!!
>
> Regards,
>
> David
>
>