mantelhaen.test for more than two groups?
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