On Tue, 1 Aug 2006, Owen, Jason wrote:
> Hello,
>
> When plotting the results of a TukeyHSD multiple comparisons
> procedure with an ANOVA (lm) object, an extra line appears
> in the confidence intervals that contain 0. For example (this
> is straight from the TukeyHSD helpfile):
>
> > summary(fm1 <- aov(breaks ~ wool + tension, data = warpbreaks))
> > TukeyHSD(fm1, "tension", ordered = TRUE)
> > plot(TukeyHSD(fm1, "tension"))
>
> An extra line segment appears in the interval to the right of the
> dotted zero line. Coincidentally, if all of the calculated
> intervals for a dataset don't contain zero, this isn't a problem
> -- so I guess the line segment "belongs" to the zero line. I
> checked R Search and didn't find this mentioned before... but
> please let me know if I overlooked something.
You overlooked the following in the posting guide
If you are using an old version of R and think it does not work
properly, upgrade to the latest version and try that, before posting.
The NEWS for 2.2.1 says
o The plot() method for TukeyHSD() needed updating after adding
adjusted p-values. (PR#8229)
which is probably what you are referring to.
>
> Jason
>
> R 2.2.0 on Windows
Far too old.
> -- BTW, the error didn't happen on my Mac OSX w/ R 1.9.1
>
> --
> Assistant Professor of Statistics
> Mathematics and Computer Science Department
> University of Richmond, Virginia 23173
> (804) 289-8081 fax:(804) 287-6664
> http://www.mathcs.richmond.edu/~wowen
>
> "This is R. There is no if. Only how."
> Simon (Yoda) Blomberg
>
> ______________________________________________
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> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
--
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)
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