p-values

Spencer,

Thank you for referring me to your other email on Exact goodness-of-fit 
test. However, I'm not entirely sure if what you mentioned is the same 
for my case. I'm not a statistician and it would help me if you could 
explain what you meant in a little more detail. Perhaps I need to 
explain the problem in more detail.

I am looking for a way to calculate exaxt p-values by Monte Carlo 
Simulation for Durbin's test. Durbin's test statistic is similar to 
Friedman's statistic, but considers the case of Balanced Incomplete 
block designs. I have found a function written by Felipe de Mendiburu 
for calculating Durbin's statistic, which gives the chi-squared p-value. 
I have also been read an article by Torsten Hothorn "On exact rank Tests 
in R" (R News 1(1), 11?12.) and he has shown how to calculate Monte 
Carlo p-values using pperm. In the article by Torsten Hothorn he gives:

R> pperm(W, ranks, length(x))

He compares his method to that of StatXact, which is the program Rayner 
and Best suggested using. Is there a way to do this for example for the 
friedman test.

A paper by Joachim Rohmel discusses "The permutation distribution for 
the friendman test" (Computational Statistics & Data Analysis 1997, 26: 
83-99). This seems to be on the lines of what I need, although I am not 
quite sure. Has anyone tried to recode his APL program for R?

I have tried a number of things, all unsucessful. Searching through 
previous postings have not been very successful either. It seems that 
pperm is the way to go, but I would need help from someone on this.

Any hints on how to continue would be much appreciated.

Peter

p-values

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