Groups > comp.lang.java.programmer > #9350

Re: RandomDirichlet?

From	Eric Sosman <esosman@ieee-dot-org.invalid>
Newsgroups	comp.lang.java.programmer
Subject	Re: RandomDirichlet?
Date	2011-11-01 20:23 -0400
Organization	A noiseless patient Spider
Message-ID	<j8q2o3$f4g$1@dont-email.me> (permalink)
References	<CAD575DC.8551%bravegag@hotmail.com> <6hrva7h1irrei62sm79ntmsr803c0np907@4ax.com>

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On 11/1/2011 9:11 AM, Roedy Green wrote:
> [...]
> I would love to figure this out to create a recipe for arbitrary
> distrtibutions for http://mindprod.com/jgloss/peudorandom.html

     The completely general approach is to find the cumulative
distribution function F(x) = P(X < x), then find its inverse F[-1],
then evaluate X = F[-1](R) for a uniformly distributed R.  The
rest is "just numerical analysis" ...

> I have a vaguely related little problem in my todo list.
> Canada has 308 members of parliament.  If there were no bias toward
> males or females, what could you say to a novice about how far  from
> 50/50 it could it stray and still be accounted for by random
> variation, not bias? Presumably using the 19 times of 20 beloved of
> pollsters.

     Google "chi-squared".

-- 
Eric Sosman
esosman@ieee-dot-org.invalid

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Thread

RandomDirichlet? Giovanni Azua <bravegag@hotmail.com> - 2011-11-01 10:09 +0100
  Re: RandomDirichlet? Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-11-01 07:50 -0400
    Re: RandomDirichlet? Giovanni Azua <bravegag@hotmail.com> - 2011-11-01 19:50 +0100
  Re: RandomDirichlet? Wojtek <nowhere@a.com> - 2011-11-01 04:54 -0700
  Re: RandomDirichlet? Roedy Green <see_website@mindprod.com.invalid> - 2011-11-01 06:11 -0700
    Re: RandomDirichlet? Roedy Green <see_website@mindprod.com.invalid> - 2011-11-01 06:16 -0700
    Re: RandomDirichlet? Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-11-01 20:23 -0400
      Re: RandomDirichlet? Roedy Green <see_website@mindprod.com.invalid> - 2011-11-02 01:39 -0700
        Re: RandomDirichlet? Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-11-02 08:17 -0400
  Re: RandomDirichlet? Arne Vajhøj <arne@vajhoej.dk> - 2011-11-01 22:09 -0400

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