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Fisher test accuracy in doubt

2 messages · joker77, Hadley Wickham

#
Hi, I noted a discrepancy between R and openepi when I ran a fisher test with
the same matrix. In R:
[,1] [,2]
[1,]    1    6
[2,]    2   17
Fisher's Exact Test for Count Data

data:  a 
p-value = 1
alternative hypothesis: true odds ratio is not equal to 1 
95 percent confidence interval:
  0.02061498 31.73691924 
sample estimates:
odds ratio 
  1.396646 

But in openepi the P value is 1.25. (In another instance too for other sets
of data, I had got a p value of 1 in 3 instances for a prop.test when I got
3 other answers on a friend's stata software with the same data. )

I'm using R on Ubuntu Intrepid. Is there anything I'm doing wrong? Any other
packages I have to install?

Thanks in advance
#
On Sat, Mar 21, 2009 at 2:03 PM, joker77 <vijumoses at gmail.com> wrote:
Given that a p-value is between 0 and 1, I would rather think that
openEpi's accuracy is in doubt.

Hadley