Date:         Mon, 7 May 2001 16:38:17 -0700
Reply-To:     kmself@IX.NETCOM.COM
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         "Karsten M. Self" <kmself@IX.NETCOM.COM>
Subject:      Re: Randomly pick
In-Reply-To:  <tfe6gejs2qhldb@corp.supernews.com>; from brian-vuong@USA.NET on
              Mon, May 07, 2001 at 02:55:47PM -0700
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on Mon, May 07, 2001 at 02:55:47PM -0700, Brian Vuong (brian-vuong@USA.NET) wrote:
> Dear SAS users:
> Please help me with random generator.  After I ran codes listed below to
> randomly pick 5000 records.  I later found that in those 5000 records
> consists of duplicates.  Please show me to randomly pick 5000 records
> without duplicates.
> 
> 
>    data select;
>        do i=1 to 400;
>            j= (ranuni(0)*total);
>            set auditing.recaudit point=j nobs=total;
>            output;
>            end ;
>        stop;
>        run;

How about:

    data ransel;
        sortby = ranuni(0);
        set auditing.recaudit;
        run;

    proc sort data= ransel;
        by sortby;
        run;

    data select;
        set ransel obs=5000;
        run;

    proc datasets lib=work;
        delete ransel;
        run;
        quit;

...not the fastest solution, but guaranteed to sample without
duplication, using a pseudorandom key.

-- 
Karsten M. Self <kmself@ix.netcom.com>    http://kmself.home.netcom.com/
 What part of "Gestalt" don't you understand?       There is no K5 cabal
  http://gestalt-system.sourceforge.net/         http://www.kuro5hin.org

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