Re: [R] mantelhaen.test for more than two groups?

From: Peter Dalgaard <p.dalgaard_at_biostat.ku.dk>
Date: Wed 27 Apr 2005 - 02:24:31 EST

Thomas Lumley <tlumley@u.washington.edu> writes:

> On Tue, 26 Apr 2005, Katrin Schweitzer wrote:
>
> > Dear All,
> >
> > I'd like to perform the generalized Cochran-Mantel-Haenszel-Test (as
> > described in Agresti (1990), Categorical Data Analysis) for my
> > nominal data.
> >
> > My problem is that I have more than two groups. In fact I think I'd
> > need an 5-dimensional array for the response variable, the control
> > variable and three group variables.
> > Could you please tell me if this is possible in R - and if yes how I
> > am supposed to do this?
>
> You're supposed to have a three-dimensional array: exposure x response
> x group.
>
> This means turning your three group variables into one variable. One
> way to do this is with the interaction() function.

Or, if data are already counts, change the dimensions (as in dim(x) <- c(2,3,8)), possibly after using aperm() to get the indices in the right order.

-- 
   O__  ---- Peter Dalgaard             Blegdamsvej 3  
  c/ /'_ --- Dept. of Biostatistics     2200 Cph. N   
 (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
~~~~~~~~~~ - (p.dalgaard@biostat.ku.dk)             FAX: (+45) 35327907

______________________________________________
R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
Received on Wed Apr 27 02:30:09 2005

This archive was generated by hypermail 2.1.8 : Fri 03 Mar 2006 - 03:31:26 EST