[R] Two-way non-parametric ANOVA?

Matthias Gondan matthias-gondan at gmx.de
Wed Jan 23 14:45:36 CET 2008

Hi Diana,

Look at Edgar Brunner's Homepage


and here:


Unfortunately, the R script for a 2x2 design with two groups and two
timepoints (f1.ld.f1.r) seems to be broken. Uncommenting the branch to
the special case "case2x2" in the script should do well, and more than 2
groups or timepoints seem to be working, too.

The basic problem with non-parametric (i.e. ordinal) Anova with more
than one factor is that the covariance matrix is not homoscedastic
anymore after a rank transformation, and autoregressive or compound
symmetry covariance structures are destroyed.

Best wishes,


Diana Perdiguero schrieb:
> We need a two-way non-parametric ANOVA in order to analysis properly some
> ecological data, do you know any reference in R? or how to do it?
> Thank you very much
> All the best
> diana

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