Hmmm, I can't reproduce, but I'm not really sure why that would happen... is there any way you can test this in a --vanilla R session? (That's the UNIX-y way to start a totally clean session; not sure exactly how to achieve that on Windows)
Does this happen if you just run example(TukeHSD) directly or only when you copy and paste the commands yourself? Hopefully we'll be able to track this down, but my initial guess is that it's some nasty combination of all the packages you have up. Michael On Wed, May 16, 2012 at 1:16 PM, Bret Jagger <cantleavethi...@gmail.com> wrote: > Hi, I am seeking help with an error when running the example from R > Documentation for TukeyHSD. The error occurs with any example I run, from > any text book or website. thank you... > >> plot(TukeyHSD(fm1, "tension")). > Error in plot(confint(as.glht(x)), ylim = c(0.5, n.contrasts + 0.5), ...) : > error in evaluating the argument 'x' in selecting a method for function > 'plot': Error in UseMethod("vcov") : > no applicable method for 'vcov' applied to an object of class "NULL" > > >> ?TukeyHSD >> require(graphics) > >> summary(fm1 <- aov(breaks ~ wool + tension, data = warpbreaks)) > Df Sum Sq Mean Sq F value Pr(>F) > wool 1 451 450.7 3.339 0.07361 . > tension 2 2034 1017.1 7.537 0.00138 ** > Residuals 50 6748 135.0 > --- > Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 >> TukeyHSD(fm1, "tension", ordered = TRUE) > Tukey multiple comparisons of means > 95% family-wise confidence level > factor levels have been ordered > > Fit: aov(formula = breaks ~ wool + tension, data = warpbreaks) > > $tension > diff lwr upr p adj > M-H 4.722222 -4.6311985 14.07564 0.4474210 > L-H 14.722222 5.3688015 24.07564 0.0011218 > L-M 10.000000 0.6465793 19.35342 0.0336262 > >> plot(TukeyHSD(fm1, "tension")) > Error in plot(confint(as.glht(x)), ylim = c(0.5, n.contrasts + 0.5), ...) : > error in evaluating the argument 'x' in selecting a method for function > 'plot': Error in UseMethod("vcov") : > no applicable method for 'vcov' applied to an object of class "NULL" >> >> sessionInfo() > R version 2.15.0 (2012-03-30) > Platform: i386-pc-mingw32/i386 (32-bit) > > attached base packages: > [1] grid tcltk splines stats graphics grDevices datasets > utils methods base > > other attached packages: > [1] RcmdrPlugin.HH_1.1-30 HH_2.2-30 latticeExtra_0.6-19 > RColorBrewer_1.0-5 > [5] leaps_2.9 multcomp_1.2-12 mvtnorm_0.9-9992 > NADA_1.5-4 > [9] ggplot2_0.9.0 Rcmdr_1.8-3 car_2.0-12 > nnet_7.3-1 > [13] DAAG_1.12 survival_2.36-12 randomForest_4.6-6 > rpart_3.1-52 > [17] RODBC_1.3-5 tree_1.0-29 spatstat_1.25-5 > mgcv_1.7-13 > [21] sciplot_1.0-9 spdep_0.5-45 coda_0.14-6 > deldir_0.0-16 > [25] maptools_0.8-14 foreign_0.8-49 nlme_3.1-103 > MASS_7.3-17 > [29] boot_1.3-4 sp_0.9-98 odesolve_0.9-9 > mcmc_0.8 > [33] lme4_0.999375-42 Matrix_1.0-6 lattice_0.20-6 > chron_2.3-42 > [37] akima_0.5-7 rcom_2.2-3.1.1 rscproxy_1.3-1 > > loaded via a namespace (and not attached): > [1] colorspace_1.1-1 dichromat_1.2-4 digest_0.5.2 memoise_0.1 > munsell_0.3 plyr_1.7.1 > [7] proto_0.3-9.2 reshape2_1.2.1 scales_0.2.0 stats4_2.15.0 > stringr_0.6 tools_2.15.0 > > [[alternative HTML version deleted]] > > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.