[R] TukeyHSD fails on my data

Prof Brian Ripley ripley at stats.ox.ac.uk
Mon May 7 22:41:51 CEST 2007

We don't have the data (nothing useful was attached - see the posting 
guide for what you can attach), but it looks like you should be using the 
'which' argument to TukeyHSD.

On Mon, 7 May 2007, Gav Wood wrote:

> Howdo folks,
> So I have my data (attached). There are two columns I'm interested in; 
> "algname" and "dur". I'd like to know how dur changes with algname. algname 
> is nominal and there are 7 possibilities. There are two more nominal 
> independents, "task" and "id", so my model is:
> dur ~ algname+task+id
> From the research I've done, a TukeyHSD seems to be what I need, so I do:
> TukeyHSD(aov(dur ~ algname+task+id, cstats), ordered=T)
> But I get this back:
> Error in rep.int(n, length(means)) : unimplemented type 'NULL' in 'rep'
> In addition: Warning messages:
> 1: non-factors ignored: task in: replications(paste("~", xx), data = mf)
> 2: non-factors ignored: id in: replications(paste("~", xx), data = mf)
> Can anyone shed any light on the situation?
> Gav

Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595

More information about the R-help mailing list