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 19A3A13877A for ; Sun, 29 Jun 2014 02:58:10 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 8E8B1E0AC3; Sun, 29 Jun 2014 02:58:04 +0000 (UTC) Received: from mail-lb0-f169.google.com (mail-lb0-f169.google.com [209.85.217.169]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id 61952E0AA0 for ; Sun, 29 Jun 2014 02:58:03 +0000 (UTC) Received: by mail-lb0-f169.google.com with SMTP id l4so5044324lbv.0 for ; Sat, 28 Jun 2014 19:58:01 -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=gqc6VXQTC359W9D0AtclHtIXW8eknpC7mgQHZidY4GI=; b=Mfoj+QJypmH2D2WX7oLFrc2EMhmHQNCoZKQenYJr1WMFU4clDS9pSeS8+/32Rglib6 TR4aFgoCbbxE3MBs1oECOjSgMJshG/8w9OuOCDdFOprtKuGRblmajtYDxWMqHdw5M9zP YW7bhcZ4IzXKTSqoplSicA5EI9Py4RzgMdRa6QpB27VvC6bvTtcTfA10BG1nIAxzD7qq tzfrfp30y7AMRWtK9hP7Qu1k+sPa3+eTLEq/9fBagoTWB4vWe+fZJDt7HFn+sbrH76Jx lhiXedVybsF2e5uGIDt+qvtdWO23f/6ZitovimRJHLFy41tsF3EchzU/a2RVSjN+80an CEOw== X-Received: by 10.152.42.172 with SMTP id p12mr23925520lal.5.1404010681568; Sat, 28 Jun 2014 19:58:01 -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 19:57:41 -0700 (PDT) In-Reply-To: <20140628204615.424f3b89@sepulchrave.remarqs> References: <20140606025619.GB3837@solfire> <20140606210329.GA1631@lyseo.edu.ouka.fi> <827EEF66-5787-4078-B18E-3D95F13B3902@iki.fi> <0ko38b-2a.ln1@hurikhan77.spdns.de> <87k380360p.fsf@nyu.edu> <20140628204615.424f3b89@sepulchrave.remarqs> From: =?UTF-8?B?Q2FuZWsgUGVsw6FleiBWYWxkw6lz?= Date: Sat, 28 Jun 2014 21:57:41 -0500 Message-ID: Subject: Re: [gentoo-user] 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: ff55d6a7-136a-46a4-a64d-6b387541bd03 X-Archives-Hash: 167a667775f61f6ac22d61a9ef8d7970 On Sat, Jun 28, 2014 at 8:46 PM, =C2=BBQ=C2=AB wrote: > On Sat, 28 Jun 2014 19:53:08 -0500 > Canek Pel=C3=A1ez Vald=C3=A9s wrote: > >> On Sat, Jun 28, 2014 at 7:37 PM, wrote: >> > On Sat, Jun 28 2014, Canek Pel=C3=A1ez Vald=C3=A9s wrote: >> > >> >> 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 is certainly true. >> > >> >> This means that it is *guaranteed* to happen >> > >> > That is not as clear. >> >> Let me be more precise (and please correct me if I'm wrong): It is >> guaranteed to happen at some point in the infinite sequence of random >> flip coins, but we cannot know when it will happen, only that it will >> happen. >> >> That's the way I got it when I took my probability courses, admittedly >> many years ago. > > The probability is 1 in the sense that the as the number of flips M > increases, so does the probability of getting N heads (or tails) in a > row also increases, and the upper bound for the sequence of > probabilities is 1. It's not a probability about something which > actually happens; no one so far has been able to flip a coin an > infinite number of times, not even a computer. And no one will. Ever. >> In any way, even if I'm wrong and it is not guaranteed, the main point >> remains true: the probability of getting a large sequence of the same >> number from a RNG is 1 for every true random RNG, and therefore seeing >> a large sequence of the same number form a RNG doesn't (technically) >> means that it is broken. > > It's true that that wouldn't *prove* the generator is broken. But it > might be a good reason to take another look at the algorithm. Agreed. Regards. --=20 Canek Pel=C3=A1ez Vald=C3=A9s Profesor de asignatura, Facultad de Ciencias Universidad Nacional Aut=C3=B3noma de M=C3=A9xico