Greetings R community, I am curious about the following behaviour: if I define a factor, and then store a subset of it in a list, the stored version seems to drop levels that were not included in the subset. E.g. ..
> mask <- c(T, F) > grp.1 <- factor(c(1,2)) > list(grp.1) [[1]] [1] 1 2 Levels: 1 2 > list(grp.1[mask]) [[1]] [1] 1 Levels: 1 It is as though the list were redefining the factor and dropping empty levels. I would like to keep them (I am using the list for a two-dimensional tapply). Is there any way to avoid this? I'm using R 2.0.0 on FreeBSD 5.2.1. Thanks, Andrew -- Andrew Robinson Ph: 208 885 7115 Department of Forest Resources Fa: 208 885 6226 University of Idaho E : [EMAIL PROTECTED] PO Box 441133 W : http://www.uidaho.edu/~andrewr Moscow ID 83843 Or: http://www.biometrics.uidaho.edu No statement above necessarily represents my employer's opinion. ______________________________________________ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
