Date:         Mon, 21 Jan 2002 16:41:17 -0500
Reply-To:     john.hixon@KODAK.COM
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         john.hixon@KODAK.COM
Subject:      Random Number Range
Comments: To: schmitta@CSD.UWM.EDU
Content-type: text/plain; charset=us-ascii

From: John Hixon

/*

Thomas Allen Schmitt <schmitta@CSD.UWM.EDU> asked:

>Hi All!  Could someone please tell me how to pull a random number from a
>uniform distribution between a specified range.  For example, pull a
>random number from a uniform distribution between 3.76 and 3.88.

>I'll add to what I wrote above in that I'm doing it in IML and need it in
>this format:

> if t = 1 then x = ge -4.00 and lt -3.88;
>    else if t = 2 then x= -3.88 and lt -3.76;
>. . . and so on.  Thanks.

>Tom

Tom, you've already been told about the ranuni() function.  Here it is used
in your context (IML).  Note that I did not pay much attention to your
endpoints (GE or LT), so, cleaning up that detail is left for you!  */

%let n=50;
%let seed=987654;   * Make this -1 if you want a diff random # each time you run the code;
                 * if you keep it a fixed #, others will be able to duplicate your;
                 * "random" numbers;
proc iml;
     t=j(&n,1,-99999);
     x=j(&n,1,-99999);
     TargMin=j(&n,1,-99999);
     TargMax=j(&n,1,-99999);
     do i=1 to &n;
          TargMin[i]=-4.00+(i-1)*0.12;
          TargMax[i]=-4.00+(i)*0.12;
          t[i]=i;
          x[i]=TargMin[i]+0.12*ranuni(&seed);
     end;
     out=t||x||TargMin||TargMax;
     create junk from out [colname={'t' 'x' 'TargMin' 'TargMax'}];
     append from out;
quit;
run;
proc print data=junk;
run;

*

HTH

John Hixon
Eastman Kodak Co
Rochester, NY USA;