Dear R-core team, I think I found a small inconsistency in the boxplot function. I don't want to post it as a bug since I'm not sure this might be considered as one according to the FAQ --- and this is not a major problem. Don't hesitate to tell me if I'm wrong.
If you try to do a boxplot on a matrix and set the "at" argument to some vector different from 1:n, n is the number of columns of your matrix, then some boxplots will be hidden since the default "xlim" value will be set to c(0.5, n + 0.5) during the call of the bxp function. Currently you can easily bypass this problem by setting "xlim" appropriately when calling the boxplot function. I think it will be better if all boxplots were always shown unless the "xlim" argument is specified. (I realized this behavior when I tried to do boxplots on conditional simulations of a stochastic process ; in which case the suggested behavior might be useful.) Here's an example par(mfrow = c(1, 3)) data <- matrix(rnorm(10 * 50), 50) colnames(data) <- letters[1:10] x.pos <- seq(-10, 10, length = 10) boxplot(data, at = x.pos) ## only the last 5 boxplots will appear boxplot(data, at = 1:10) ## all boxplots will appear boxplot(data, at = x.pos, xlim = range(x.pos) + c(-0.5, 0.5)) ## all boxplots will be shown I tried to do a patch if you want to change the current behavior --- note this is my first patch ever so maybe I'm doing it wrong. *** Downloads/R-2.14.0/src/library/graphics/R/boxplot.R Mon Oct 3 00:02:21 2011 --- boxplot.R Thu Nov 17 23:02:45 2011 *************** *** 203,209 **** } if(is.null(pars$xlim)) ! xlim <- c(0.5, n + 0.5) else { xlim <- pars$xlim pars$xlim <- NULL --- 203,209 ---- } if(is.null(pars$xlim)) ! xlim <- c(min(at) - 0.5, max(at) + 0.5) else { xlim <- pars$xlim pars$xlim <- NULL ----------------------------------------------------------------- I3M, UMR CNRS 5149 Universite Montpellier II, 4 place Eugene Bataillon 34095 Montpellier cedex 5 France http://www.math.univ-montp2.fr/~ribatet Tel: + 33 (0)4 67 14 41 98 ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel