'On Tue, Dec 7, 2010 at 5:19 AM, mxkuhn <mxk...@gmail.com> wrote: > Greg and Frank, > > Thanks for the replies. I didn't express myself very well; I'm not interest > in the model fitting aspect. I'd just like to get the full set of dummy > variables (optimally from model.matrix) >
Try this: levels(when$time) <- c("morning", "afternoon", "night") levels(when$day) <- c("Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun") contr.dummy <- function(n, ...) diag(n) mm <- suppressWarnings(model.matrix(~ day + time, when)) mm[is.na(mm)] <- 1 mm You might also want to set the levels of your factors first so that it includes levels that are not in the data and so that the levels are sorted in an order other than alphabetical: etc. -- Statistics & Software Consulting GKX Group, GKX Associates Inc. tel: 1-877-GKX-GROUP email: ggrothendieck at gmail.com ______________________________________________ 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.