> >
> > My goal is to generate all possible contingency tables. Basically I want
> > to see the distribution of Chi-squared Statistic under independence
> > (NULL).
> >
> > So I was thinking if I can generate all possible permutation of integer
> > numbers having sum equal to (8 + 10 + 12 + 6) = 36. Is there any R
> > function to do that?
I think R *can* do this (thanks to Robin Hankin):
library(partitions)
str(parts(36))
'partition' int [1:36, 1:17977] 36 0 0 0 0 0 0 0 0 0 ...
I'm not quite clear on how you're going to take these results
and turn them into possible tables, but I guess you do ...
You might also be interested in the simulate.p.value option to
chisq.test and the randomizer (which preserves row and column
totals): from the code of chisq.test,
tmp <- .Call(C_chisq_sim, sr, sc, B, E)
> >>> -----Original Message-----
> >>> From: bogaso.christofer <at> gmail.com
> >>> Let say I have 2-way contingency table:
> >>>
> >>> Tab <- matrix(c(8, 10, 12, 6), nr = 2)
> >>>
> >>> and the Chi-squared test could not reject the independence:
> >>>
> >>> > chisq.test(Tab)
> >>>
> >>> Pearson's Chi-squared test with Yates' continuity correction
> >>>
> >>> data: Tab
> >>> X-squared = 1.0125, df = 1, p-value = 0.3143
> >>>
> >>>
> >>> However I want to get all possible contingency tables under this
> >>> independence scenario (one of them would obviously be the given table
> >>> as, we could not reject the independence), and for each such table I
> >>> want to calculate the Ch-sq statistic.
> >>>
> >>> Can somebody help me how to generate all such tables?
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