|The stupid question is the question not asked|
Re: Fisher's Exact Testby resonator (Initiate)
|on Apr 18, 2007 at 17:41 UTC||Need Help??|
Have you checked the results of your code for Fisher's Exact Test? I don't think it produces correct results.
Here's a utility that produces results identical to those I calculate:
This expression at the beginning of your code seems odd:
> $test = $a*($a+$b+$c+$d ) - ($a+$b)*($a+$c);
It simplifies to $test = $a*$d - $b*$c;
I don't follow why you have this:
return 1 if $test < 0 and $ts;
For example, if a = 1, b = 50, c = 10 and d = 5, P(one-sided) = P(two-sided) = 1.4386e-07, not 1.
Nevertheless, thanks for the tip about calculating factorials only once. Let me know if I've misunderstood something.