From owner-freebsd-hackers Mon Oct 7 13:55:53 1996 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id NAA27853 for hackers-outgoing; Mon, 7 Oct 1996 13:55:53 -0700 (PDT) Received: from sag.space.lockheed.com (sag.space.lockheed.com [192.68.162.134]) by freefall.freebsd.org (8.7.5/8.7.3) with SMTP id NAA27846 for ; Mon, 7 Oct 1996 13:55:50 -0700 (PDT) Received: from localhost by sag.space.lockheed.com; (5.65v3.2/1.1.8.2/21Nov95-0423PM) id AA19787; Mon, 7 Oct 1996 13:53:29 -0700 Date: Mon, 7 Oct 1996 13:53:29 -0700 (PDT) From: "Brian N. Handy" Reply-To: "Brian N. Handy" To: Terry Lambert Cc: Poul-Henning Kamp , ache@nagual.ru, rkw@dataplex.net, freebsd-hackers@FREEBSD.ORG Subject: Re: I plan to change random() for -current (was Re: rand() and random()) In-Reply-To: <199610071915.MAA14666@phaeton.artisoft.com> Message-Id: X-Files: The truth is out there Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-hackers@FREEBSD.ORG X-Loop: FreeBSD.org Precedence: bulk >This was not the only physicist who has sidebarred me, and a number >of mathematicians and physical chemists and at least one X-ray >crystallographer have also chimed in. I don't get it! I just *don't* understand this. Oh, in light of another post: M.S., Physics. (Ph.D., Physics, in progress.) Having taken a boatload of math and physics classes on the subject, I have noted that the mathematicians are typically quite a bit better at making sure they have a real random number generator. The physicists generally look for a black box, but at least most of the folks I've known have read the appropriate sections from _Numerical Recipes_. (Yep, mathematicians will often cringe at this book, but it's better than nothing.) And they ALL know not to use the system random function. That's about the first thing I was taught in school. Scientific applications *can't* depend on the system rand() functions! And I'm unaware of anybody in the field(s) that depends on the system random number generator! If you want control over your rand() -- you brew your own! You sure don't want to depend on the system version. Depending on the system version is counter productive. You go to a GREAT deal of work to get your numerical simulation to work -- why would you want to cripple it with a broken rand()? Regards, Brian