Path: csiph.com!usenet.pasdenom.info!gegeweb.org!de-l.enfer-du-nord.net!feeder2.enfer-du-nord.net!feeds.phibee-telecom.net!newsfeed.xs4all.nl!newsfeed3.news.xs4all.nl!xs4all!post.news.xs4all.nl!not-for-mail Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.031 X-Spam-Evidence: '*H*': 0.94; '*S*': 0.00; 'algorithm': 0.04; 'kind,': 0.05; 'tests.': 0.07; 'variables': 0.07; 'imply': 0.09; 'subtle': 0.09; 'subject:question': 0.10; 'suggest': 0.14; 'random': 0.14; "wouldn't": 0.14; '24,': 0.16; '5:00': 0.16; 'behavior,': 0.16; 'cheaper.': 0.16; 'correlation': 0.16; 'interval,': 0.16; 'iteration': 0.16; 'means.': 0.16; 'nodes': 0.16; 'sequence,': 0.16; 'subject: \n ': 0.16; 'when,': 0.16; 'wrote:': 0.18; 'bit': 0.19; 'to:name:python-list@python.org': 0.22; 'mathematical': 0.24; 'precise': 0.24; 'received:65.55.116': 0.24; 'question': 0.24; 'header:In-Reply-To:1': 0.27; 'skip:- 40': 0.29; 'related': 0.29; 'usually': 0.31; 'concern.': 0.31; 'run': 0.32; 'fri,': 0.33; 'date:': 0.34; "can't": 0.35; 'connection': 0.35; 'there': 0.35; 'sequence': 0.36; 'subject:Simple': 0.36; 'should': 0.36; 'email addr:python.org': 0.37; 'being': 0.38; 'somebody': 0.38; 'to:addr:python-list': 0.38; 'pm,': 0.38; 'that,': 0.38; 'does': 0.39; 'subject:': 0.39; 'to:addr:python.org': 0.39; 'how': 0.40; 'skip:u 10': 0.60; 'is.': 0.60; 'negative': 0.60; 'then,': 0.60; 'simple': 0.61; 'email addr:gmail.com': 0.63; 'show': 0.63; 're:': 0.63; 'happen': 0.63; 'more': 0.64; 'taking': 0.65; 'email name :python-list': 0.65; 'series': 0.66; 'world': 0.66; 'between': 0.67; 'close': 0.67; 'it!': 0.67; 'believe': 0.68; 'fact,': 0.69; 'effects,': 0.84; 'recognition': 0.84; 'updated,': 0.84; 'carlos': 0.91; 'simulation': 0.91; '2013': 0.98 X-TMN: [TW5tpffNE2OJEFdFRg31b2/VKlwSe2+x] X-Originating-Email: [carlosnepomuceno@outlook.com] From: Carlos Nepomuceno To: "python-list@python.org" Subject: RE: Simple algorithm question - how to reorder a sequence economically Date: Sat, 25 May 2013 00:33:01 +0300 Importance: Normal In-Reply-To: <358d5be7-87e8-4655-82ba-859786cc3d47@l3g2000vbl.googlegroups.com> References: , , <358d5be7-87e8-4655-82ba-859786cc3d47@l3g2000vbl.googlegroups.com> Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginalArrivalTime: 24 May 2013 21:33:02.0002 (UTC) FILETIME=[44B84920:01CE58C6] X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Newsgroups: comp.lang.python Message-ID: Lines: 44 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1369431189 news.xs4all.nl 16002 [2001:888:2000:d::a6]:34822 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:45921 ----------------------------------------=0A= > Date: Fri=2C 24 May 2013 12:01:35 -0700=0A= > Subject: Re: Simple algorithm question - how to reorder a sequence econom= ically=0A= > From: peter.h.m.brooks@gmail.com=0A= > To: python-list@python.org=0A= >=0A= > On May 24=2C 5:00 pm=2C Carlos Nepomuceno = =0A= > wrote:=0A= >>=0A= >>=0A= >> I don't know what "spurious evidence of correlation" is. Can you give a = mathematical definition?=0A= >>=0A= > If I run the simulation with the same sequence=2C then=2C because event E= 1=0A= > always comes before event E2=2C somebody might believe that there is a=0A= > causative connection between them in the world that's being simulated=2C= =0A= > when=2C in fact=2C they only correlate in this way because the sequence i= s=0A= > not being shuffled. That's what it means.=0A= =0A= Correlation does not imply causation. If "somebody" is an expert system and= you want to avoid it's recognition and/or triggering of some kind=2C and y= ou can't or don't want to change it's behavior=2C you may take the random w= ay because it's cheaper.=0A= =0A= > Actually it'll be a bit more subtle than that=2C because each iteration= =0A= > of the simulation updates all nodes in one time interval=2C the events=0A= > will not usually show the order of iteration - but=2C where there are=0A= > any secondary effects=2C that are related to the order in which the=0A= > nodes are updated=2C these will always happen the same way=2C which is my= =0A= > concern.=0A= =0A= You should have a more precise understanding of the dependence of the varia= bles you taking in consideration before randomizing the series of events yo= ur are using for tests.=0A= =0A= I suggest you start using PPMCC. If it's close to zero or negative you woul= dn't have to mind about it! =3B) =