search for: defactorise

...str(d) str(d2) I'd like to write a function factorise() which takes a data.frame and a vector of variable names, and returns the original data.frame with the desired variables converted to factor, factorise <- function(d, f) ***ply(d, f, factor) # some apply function also, perhaps a defactorise() function doing the reverse operation with as.numeric. I played with the plyr package and the base apply family for a while but can't find any concise construct. Best regards, baptiste _____________________________ Baptiste Augui? School of Physics University of Exeter Stocker Road...