http://stackoverflow.com/questions/1195826/dropping-factor-levels-in-a-subsetted-data-frame-in-r
-----Original Message----- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of Knut Helge Jensen Sent: Friday, August 07, 2009 5:02 AM To: r-h...@stat.math.ethz.ch Subject: [R] bug with subset and plot? Hi! I have the following problem that I beleive is a bug: I have a dataframe with one categorical and one numerical vector. The categorical vector has three levels (uc, up and vc). A plot of the vectors with the categorical vector on the x-axis gives a boxplot with three boxes - exactly as expected. If I then use the subset function to make a dataset that only includes two of the levels of the categorical vector and do the plot again, all three levels are still shown on the x-axis even though one of them doesn't exist in the dataset. The plot shows correct number of boxes (2). The whole syntax for what I describe is as follows: exploration.df <- read.table('clipboard', header=T) attach(exploration.df) plot(treatment,total.escapes) exp.df <- subset(exploration.df, treatment!='up') attach(exp.df) plot(treatment, total.escapes) I use R version 2.9.1 (2009-06-26) for Debian. Knut Helge Jensen ______________________________________________ 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.
