Ivan Calandra <ivan.calandra <at> uni-hamburg.de> writes: > > Hi, > > I knew about that way already, with factor(). Isn't there another > possibility, directly at the subsetting step? That would be of great help > iris1 <- iris[iris$Species == 'setosa',] ## I mean here > > Ivan Not as far as I know. See gdata::drop.levels , or droplevels() in R 2.12.0.