Date:         Fri, 18 Apr 2008 14:09:23 -0400
Reply-To:     Sigurd Hermansen <HERMANS1@WESTAT.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Sigurd Hermansen <HERMANS1@WESTAT.COM>
Subject:      Re: anybody can help with this function?
Comments: To: "data _null_," <datanull@gmail.com>
In-Reply-To:  <7367b4e20804181048t2ab739a4oc3b67b9fb827d477@mail.gmail.com>
Content-Type: text/plain; charset="us-ascii"

Yes. I guess I didn't phrase that quite right. Thanks for the correct
interpretation and CALL example.
S

-----Original Message-----
From: data _null_, [mailto:datanull@gmail.com]
Sent: Friday, April 18, 2008 1:49 PM
To: Sigurd Hermansen
Cc: SAS-L@listserv.uga.edu
Subject: Re: anybody can help with this function?


On Fri, Apr 18, 2008 at 12:30 PM, Sigurd Hermansen <HERMANS1@westat.com>
wrote:
>   /* Only for purpose of showing random value and that same seed
> generates same series. */

You don't have that quite right.  The second call in your example uses
the same stream as the first.  Thus the two call do NOT produce the same
random number.  You have to use call ranuni for that see next example.

It goes something like this.  assign a seed.  Call the function.  The
function actually return 2 numbers one is the random number the other is
the seed for the next call.  For the function form SAS just has one
place to hold the seed.  So other calls use the same value and update
the seed.

data _null_;
   do i=1 to 100;
      y0 = ranuni(12371);
      if y0>0.5 then y=1; else y=0;
      /* Ranuni function uses just one stream*/
      x=ranuni(12371);
      put i= x= y0= y= ;
      end;
   run;

data _null_;
   retain seed1 seed2 12371;
   do i=1 to 100;
      call ranuni(seed1,y0);
      if y0>0.5 then y=1; else y=0;
      /* call Ranuni allows different streams*/
      call ranuni(seed2,x);
      put i= x= y0= y= seed1= seed2=;
      end;
   run;