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

[Thomas Lumley]

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.

 	-thomas

Thomas Lumley			Assoc. Professor, Biostatistics
tlumley at u.washington.edu	University of Washington, Seattle