Hello all. Trying to use transparency for overlaid "histogram" plots I have come across an interesting inconsistency, possibly a bug when running under Windows. Originally noticed in R 2.7.1, it is still there in 2.8.0 beta.
library(lattice) zz <- function(n,alpha) { ranges <- NULL for(ds in 1:n){ ranges <- rbind(ranges,data.frame(confidence=c(0,100),dataset=as.character(ds),cor rect=c(FALSE,TRUE))) } panel.colhist = function(x, group.number, col, ...) { panel.histogram(x, col=group.number+1, ...) } x <- histogram(~confidence|dataset,data=ranges,alpha=alpha, panel=panel.superpose,panel.groups=panel.colhist,groups=correct) print(x) } zz(12,1) # works as expected, 12 identical plots zz(12,0.5) # top row of plots has no bars at all, lower rows are as expected zz(1,1) # two bars fine zz(1,0.5) # no bars at all (I also find the default breaks slightly counter-intuitive here, as the number of breaks seems to depend on the total size of the data, rather than on the size within each plot - the bars meet in the zz(1,1) case but are well separated in the zz(12,1) case.) I am running on 64-bit Windows Vista Business SP1, session info is as follows: R version 2.8.0 beta (2008-10-07 r46631) i386-pc-mingw32 locale: LC_COLLATE=English_United Kingdom.1252;LC_CTYPE=English_United Kingdom.1252;LC_MONETARY=English_United Kingdom.1252;LC_NUMERIC=C;LC_TIME=English_United Kingdom.1252 attached base packages: [1] stats graphics grDevices utils datasets methods base other attached packages: [1] lattice_0.17-15 loaded via a namespace (and not attached): [1] grid_2.8.0 It appears to work correctly under (Suse) linux, with the following session characteristics: R version 2.7.2 (2008-08-25) i686-pc-linux-gnu locale: LC_CTYPE=en_GB.UTF-8;LC_NUMERIC=C;LC_TIME=en_GB.UTF-8;LC_COLLATE=en_GB.U TF-8;LC_MONETARY=C;LC_MESSAGES=en_GB.UTF-8;LC_PAPER=en_GB.UTF-8;LC_NAME= C;LC_ADDRESS=C;LC_TELEPHONE=C;LC_MEASUREMENT=en_GB.UTF-8;LC_IDENTIFICATI ON=C attached base packages: [1] stats graphics grDevices utils datasets methods base other attached packages: [1] lattice_0.17-13 loaded via a namespace (and not attached): [1] grid_2.7.2 sysname release "Linux" "2.6.22.18-0.2-default" version nodename "#1 SMP 2008-06-09 13:53:20 +0200" "node76" machine login "i686" "kponting" user "kponting" Keith Ponting Aurix Ltd, Malvern WR14 3SZ UK ______________________________________________ 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.