Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!uunet!mcsun!hp4nl!star.cs.vu.nl!condict
From: condict@cs.vu.nl (Michael Condict)
Newsgroups: comp.lang.c
Subject: Re: Random number generator
Keywords: random maxint
Message-ID: <4943@condict.cs.vu.nl>
Date: 22 Dec 89 15:25:21 GMT
References: <83943@linus.UUCP>
Reply-To: condict@cs.vu.nl (Michael Condict)
Organization: VU Informatica, Amsterdam
Lines: 28

In article <83943@linus.UUCP> rtidd@mwsun.mitre.org writes:
|Greetings 
|
|I was trying to generate a random number bewteen 0 and maxlongint (i.e. 2^32)
|on my machine (80386 with Interactive). The rand() function that I have
|returns a psuedo-random number between 0 and MAXINT (which in this case
|is 32768). I thought about generating two random numbers and multiplying
|them together, but I realized that would produce a bell-curve-shaped
|distrubution (the numbers in the middle would be more likely to occur).
|
|Does anyone have any ideas or any code that generates random numbers,
|or anyplace that I can check to find such code?
|

Generate the two 16-bit numbers and concatenate them:

	long_random = (short_random_1 << 16) + short_random_2;

Or, if you prefer:

	long_random = short_random_1 * 65536 + short_random_2;

If the rand function generates uniformly distributed random shorts,
this will obviously produce uniformly distributed random longs.
-- 
Michael Condict		condict@cs.vu.nl
Vrije University
Amsterdam