[R] T statistic exactRankTests package
ehlers at ucalgary.ca
Fri May 31 00:25:34 CEST 2013
On 2013-05-30 04:20, Al Zou wrote:
> I understand this might be a silly question, but I have problems
> understanding the statistic term returned in most permutation packages.
> for example:
> 1-sample Permutation Test
> data: x and y
> T = 6, p-value = 0.25
> alternative hypothesis: true mu is not equal to 0
>  "statistic" "p.value" "pointprob" "null.value" "alternative"
> "method" "data.name"
>  "htest"
> I cannot figure out what the T stands for. I understand it is "T statistic"
> but it is not the t-score.
> Can some one tell me what formula is used for the T statistic.
The formula is simple: T is the sum of the positive paired differences.
You could check Wikipedia for "permutation test". There must be plenty
of online info but I'm too lazy to check.
> In general is there some way to look for what function is used to calculate
> the statistics?
Just look at the code of perm.test.default (it's not complicated).
to see the code or get the package source and study the code.
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