>>>>> "anja" == anja von heydebreck <[EMAIL PROTECTED]>
>>>>> on Wed, 7 Jul 2004 17:19:01 +0200 (CEST) writes:
anja> Full_Name: Anja von Heydebreck Version: 1.9.1 OS:
anja> Linux Submission from: (NULL) (155.250.128.25)
anja> I obtained a negative p-value from the fisher.test()
anja> function:
>> fisher.test(matrix(c(14576,3023,89,68),2),
>> alternative="g")$p.value
anja> [1] -8.426593e-13
[I do get a slightly different negative P-value here].
anja> With R 1.8.1, I got a p-value of -6.239231e-12 for
anja> this example.
(which is slightly worse ;-)
anja> Anja von Heydebreck
Thank you, Anja!
Note that this is the 2x2 case which does not resort to the
(in)famous FEXACT routine. The rounding / precision problem is
rather from dhyper() and/or phyper().
Now, as bug report PR#6772 "phyper accuracy and efficiency",
Morten Welinder
had proposed a new algorithm for phyper().
I'm about to try that and see if it cures this example.
Best regards,
Martin Maechler
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