Message-ID: <XFMail.110107174252.ted.harding@wlandres.net>
Date: 2011-01-07T17:42:52Z
From: (Ted Harding)
Subject: how to calculate this natural logarithm
In-Reply-To: <201101080020557148176@yahoo.com.cn>
On 07-Jan-11 16:20:59, zhaoxing731 wrote:
> Hello
> I want to calculate natural logarithm of sum of combinations
> as follow: (R code)
{com_sum=choose(2000000,482)*choose(1000000,118)+
choose(2000000,483)*choose(1000000,117)+...+
choose(2000000,i)*choose(1000000,600-i)+...+
choose(2000000,600)*choose(1000000,0) #calculate the sum
result=log(com_sum) #calculate the log of the sum
}
> But every element of the com_sum is Inf, so I can't get the
> result. Thank you in advance
> Yours sincerely
> ZhaoXing
You may find you can usefully adapt the technique I have
described in:
http://www.zen89632.zen.co.uk/R/FisherTest/extreme_fisher.pdf
A somewhat different but closely related problem.
Ted.
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Date: 07-Jan-11 Time: 17:42:48
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