Article View: aus.mathematics
Article #137Re: Deriving natural logarithms
From: eugene Eugene Griessel
Date: Thu, 01 Feb 2007 20:11
Date: Thu, 01 Feb 2007 20:11
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Barb Knox <see@sig.below> wrote: >In article <45c1a555.9738971@news.uunet.co.za>, > eugene@dynagen..co..za (Eugene Griessel) wrote: > >> Is it possible, even by Newton-Raphson, to derive the natural >> logarithm of a number using nothing more than addition, subtraction, >> division and multiplication? I would be keen to get an algorithm to >> do this - have been trying to derive one myself but with no success. > >A common method is to use a power series (e.g. Taylor series). > The Taylor series requires raising numbers to powers IIRC. I have found an elegantly simple 3 step algorithm that seems to work well - I have tested it extensively and it gives the results I require! Thanks. (Personally I have not worked with logs since the 70's! - computers and calculators seem to have killed the need for most people!) Eugene L Griessel I sometimes think that God in creating man somewhat overestimated his ability.
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X-Google-Thread: 10d67e,eb0c44a415842402 X-Google-Attributes: gid10d67e,public X-Google-Language: ENGLISH,ASCII-7-bit Path: arc1-ca.pugleaf.net!g2news2.google.com!news1.google.com!news3.google.com!border1.nntp.dca.giganews.com!nntp.giganews.com!nx02.iad01.newshosting.com!newshosting.com!newsfeed.icl.net!newsfeed.fjserv.net!newsfeed.freenet.de!news.tiscali.de!tiscali!newsfeed1.ip.tiscali.net!news.tele.dk!news.tele.dk!small.news.tele.dk!lnewsinpeer00.lnd.ops.eu.uu.net!bnewsinpeer00.bru.ops.eu.uu.net!emea.uu.net!uunet.co.za!newsreader02.ops.uunet.co.za!newsreader02.ops.uunet.co.za!not-for-mail From: eugene@dynagen..co..za (Eugene Griessel) Newsgroups: aus.mathematics Subject: Re: Deriving natural logarithms Date: Thu, 01 Feb 2007 20:11:43 GMT Organization: Noordhoek Henge and Solstice Society Lines: 24 Message-ID: <45c248cc.590443@news.uunet.co.za> References: <45c1a555.9738971@news.uunet.co.za> <see-80BBC6.09073502022007@lust.ihug.co.nz> Reply-To: eugene@dynagen..co..za X-Trace: newsreader02.ops.uunet.co.za 1170360706 46406 196.30.44.140 (1 Feb 2007 20:11:46 GMT) X-Complaints-To: abuse@uunet.co.za X-Newsreader: Forte Free Agent 1.21/16.243