From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) by finch.gentoo.org (Postfix) with ESMTP id 50F9813877A for ; Sat, 28 Jun 2014 22:07:05 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id BD164E0AB4; Sat, 28 Jun 2014 22:06:57 +0000 (UTC) Received: from mail-la0-f44.google.com (mail-la0-f44.google.com [209.85.215.44]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id 6DEA5E08E0 for ; Sat, 28 Jun 2014 22:06:56 +0000 (UTC) Received: by mail-la0-f44.google.com with SMTP id ty20so3923775lab.31 for ; Sat, 28 Jun 2014 15:06:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :content-type:content-transfer-encoding; bh=hfQHG59jQfOtpkpQJfy0yQcKAi5/IaRlMrxCP8HpEwM=; b=ppUGs/XMJXk6P/DzLPPcgFMyn9rMMOnOhdkQ834edjuEW74I/jAv0QR/VpfkIQHP+1 /eBt/yhtmkkMEiY9IgZr7OtcLFnLsvqbuvHxDpn4669nVEGAoaNhQFx1o079TonLORCA qPQW4lTBIwnbPWQA+lGaXgeoEm2s6gwODz67RPjyqYA1mt4yUHSkgkJbKGrXWtMYmVFw lDsxg0Jc8VQqHu0wBBo0niGHTBXmQTZukdS1ORIDmcLotknHL2BdRfVh7HUh5efceL0p UBsFjZ7kLNw495iBO51IOLafuKLFkAMXavN0NTjsU/sqaZoLDjb7vx7U0lTcyEfzJvIe fMzQ== X-Received: by 10.152.1.99 with SMTP id 3mr23255169lal.43.1403993214462; Sat, 28 Jun 2014 15:06:54 -0700 (PDT) Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 Received: by 10.114.170.166 with HTTP; Sat, 28 Jun 2014 15:06:33 -0700 (PDT) In-Reply-To: <0ko38b-2a.ln1@hurikhan77.spdns.de> References: <20140606025619.GB3837@solfire> <20140606210329.GA1631@lyseo.edu.ouka.fi> <827EEF66-5787-4078-B18E-3D95F13B3902@iki.fi> <0ko38b-2a.ln1@hurikhan77.spdns.de> From: =?UTF-8?B?Q2FuZWsgUGVsw6FleiBWYWxkw6lz?= Date: Sat, 28 Jun 2014 17:06:33 -0500 Message-ID: Subject: Re: [gentoo-user] Re: Re: OT: Mapping random numbers (PRNG) To: gentoo-user@lists.gentoo.org Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Archives-Salt: 8e2dc229-8604-4f52-b86d-a795cf204a2f X-Archives-Hash: c5a68729a56a6c45e87ff7a7542dbc5f On Sat, Jun 28, 2014 at 4:28 PM, Kai Krakow wrote: [ ... ] > I cannot follow your reasoning here - but I'd like to learn. Actually, I = ran > this multiple times and never saw long sets of the same character, even n= o > short sets of the same character. The 0 or 1 is always rolled over into t= he > next random addition. That doesn't matter. Take a non-negative integer N; if you flip a coin an infinite number of times, then the probability of the coin landing on the same face N times in a row is 1. This means that it is *guaranteed* to happen, and it *will* happen for any N you want: 1,000,000, a thousand billions, a gazillion. That is a mathematical fact. This of course is a consequence of "infinite" being really really large, but it means that technically you cannot rule a RNG as broken only because you saw that it produced the same result N times, which is the crux of the Dilbert joke. In practice, of course, it's a big sign that something is wrong. But there is a non-zero probability that it's actually correct. Because with randomness, you can never be sure. Regards. --=20 Canek Pel=C3=A1ez Vald=C3=A9s Profesor de asignatura, Facultad de Ciencias Universidad Nacional Aut=C3=B3noma de M=C3=A9xico