Date:         Wed, 28 Apr 2004 22:17:05 -0700
Reply-To:     Dale McLerran <stringplayer_2@YAHOO.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Dale McLerran <stringplayer_2@YAHOO.COM>
Subject:      Re: writing efficient code - macro???
Comments: To: Noreen McDonald <noreen@BERKELEY.EDU>
In-Reply-To:  <web-2361318@calmail-ma.berkeley.edu>
Content-Type: text/plain; charset=us-ascii

--- Noreen McDonald <noreen@BERKELEY.EDU> wrote:
> Being at the beginning of the SAS learning curve, I have a problem
> which I've seen a few times.
>  There are many times I want to use a counter variable in multiple
> ways, ie to identify position
> in matrix or a particular variable.  I've only been able to solve it
> inelegantly using wallpaper
> code.  If anyone could show me how to do it better, I would greatly
> appreciate it.  It's probably
> best explained by an example.   Noreen
> data test;/*wallpaper approach*/
>         array dummy(*) dummy1-dummy5;
>         set temp;
>         if var1=1 then dummy(1)=num1;
>         if var2=2 then dummy(2)=num2;
>         /*And so on... You get the idea ...*/
> run;
> What I would like is to create a counter variable which I could use
> like so:
> data test;/*just an idea of what I want, code doesn't work*/
>         array dummy(*) dummy1-dummy5;
>                       do i=1 to 5;
>         set temp;
>         if var&i=i then dummy(i)=num&i;
> /* is there a way to use counters to identify variables ,e.g. var1,
> var2*/
>   run;
>

Noreen,

There is no need for macro code here.  A macro could be used to
write your "wallpaper" code.  That could make it a little easier
to write all of the assignment statements.  However, it does
nothing to reduce the complexity of the code.

The simple solution is to declare arrays for var1-var5 and n1-n5
along with the array for dummy1-dummy5.  You can loop over a
datastep variable i to index the array positions.

  data test;
      array dummy {5} dummy1-dummy5;
      array var   {5} var1-var5;
      array n     {5} n1-n5;
      set temp;
      do i=1 to 5;
        if var{i}=i then dummy(i)=num{i};
      end;
  run;


Dale


=====
---------------------------------------
Dale McLerran
Fred Hutchinson Cancer Research Center
mailto: dmclerra@fhcrc.org
Ph:  (206) 667-2926
Fax: (206) 667-5977
---------------------------------------




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