[Rd] chisq.test with simulate.p.value=TRUE (PR#13292)
constant at unb.br
constant at unb.br
Sun Nov 16 01:00:09 CET 2008
Full_Name: Reginaldo Constantino
Version: 2.8.0
OS: Ubuntu Hardy (32 bit, kernel 2.6.24)
Submission from: (NULL) (189.61.88.2)
For many tables, chisq.test with simulate.p.value=TRUE gives a p value that is
obviously incorrect and inversely proportional to the number of replicates:
> data(HairEyeColor)
> x <- margin.table(HairEyeColor, c(1, 2))
> chisq.test(x,simulate.p.value=TRUE,B=2000)
Pearson's Chi-squared test with simulated p-value (based on 2000
replicates)
data: x
X-squared = 138.2898, df = NA, p-value = 0.0004998
> chisq.test(x,simulate.p.value=TRUE,B=10000)
X-squared = 138.2898, df = NA, p-value = 1e-04
> chisq.test(x,simulate.p.value=TRUE,B=100000)
X-squared = 138.2898, df = NA, p-value = 1e-05
> chisq.test(x,simulate.p.value=TRUE,B=1000000)
X-squared = 138.2898, df = NA, p-value = 1e-06
...
Also tested the same R version under Windows XP and got the same results.
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