Article View: comp.lang.pascal.delphi.misc
Article #722Re: Buffon's Needles
From: Dr John Stockton
Date: Sun, 27 Jun 1999 00:00
Date: Sun, 27 Jun 1999 00:00
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2935 bytes
JRS: In article <7l357k$4m6$1@nnrp1.deja.com> of Sat, 26 Jun 1999
18:13:14 in news:comp.lang.pascal.delphi.misc, David C. Ullrich
<ullrich@math.okstate.edu> wrote:
>In article <zZIi7jAzW8c3EwDD@merlyn.demon.co.uk>,
> Dr John Stockton <jrs@merlyn.demon.co.uk> wrote:
> I have no idea what a "subset-capability" is, but modulo
>that of course there is. Set one endpoint P1 of the needle to a
>random point in a large square. Then set the other endpoint
>to another random point. Reject the second endpoint until you
>get one with say 0.5 < |P1 - P2| < 2. Then rescale it so
>|P1 - P2| = 1. There's your random needle, no trig and hence
>no Pi required.
>
> ("rescale": say P2 := P1 + (P2 - P1)/|P2 - P1| . No
>angles, just a square root.)
ISTM, seemingly confirmed by test, that your method does not give a
uniform distribution of angles.
>> It must be better still to glue large numbers, evenly distributed in
>> angle, together - centrally to get a disc, or endwise to get a ring.
>> Not too many, though; with an infinite number of needles, unless
>> carefully treated, there's a risk of getting infinity/infinity as the
>> result.
>
> Huh? The limit in question _is_ a limit "of the form
>infinity/infinity". I don't think there's much danger of
>the actual algorithm running infinitely many times.
With an infinite number of needles glued together, the algorithm need
only be run once - though this will take infinite time.
--
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X-Google-Language: ENGLISH,ASCII X-Google-Thread: 10a726,d24982a2aa52a35f X-Google-Attributes: gid10a726,public X-Google-Thread: 10baee,d24982a2aa52a35f X-Google-Attributes: gid10baee,public X-Google-Thread: 105ac8,d24982a2aa52a35f X-Google-Attributes: gid105ac8,public X-Google-Thread: 10a7f1,d24982a2aa52a35f X-Google-Attributes: gid10a7f1,public From: Dr John Stockton <jrs@merlyn.demon.co.uk> Subject: Re: Buffon's Needles Date: 1999/06/27 Message-ID: <3zADx9AXVWd3EwJU@merlyn.demon.co.uk> X-Deja-AN: 494275356 Content-Transfer-Encoding: 8bit X-NNTP-Posting-Host: merlyn.demon.co.uk:158.152.233.145 References: <7ks8ls$mgk$1@bgtnsc03.worldnet.att.net> <Im0c0MABmjc3Ew2K@merlyn.demon.co.uk> <zZIi7jAzW8c3EwDD@merlyn.demon.co.uk> <7l357k$4m6$1@nnrp1.deja.com> Content-Type: text/plain;charset=iso-8859-1 X-Complaints-To: abuse@demon.net X-Trace: news.demon.co.uk 930440641 nnrp-04:25468 NO-IDENT merlyn.demon.co.uk:158.152.233.145 Organization: Home, Surrey, UK MIME-Version: 1.0 Newsgroups: comp.lang.pascal.delphi.misc,alt.comp.borland-delphi,de.comp.lang.pascal.delphi,fr.comp.lang.pascal