There are lot's of ways of doing things in R, and I am always learning. I always use vectorized functions when I do something to every row in a data.frame, but

There are lot's of ways of doing things in R, and I am always learning. I always use vectorized functions when I do something to every row in a data.frame, but when I want to do something to every column, like here, I sometimes use for. How would you use something like plyr here, and would it be as easy to understand? likertcat <- c("1"="Not at all", "2"="To a small extent", "3"="To some extent", "4"="To a moderate extent", "5"="To a large extent") for(e in names(db[,9:44])) { db[[e]] <- revalue(db[[e]], likertcat) db[[e]] <- ordered(db[[e]], levels= c("Not at all","To a small extent", "To some extent","To a moderate extent","To a large extent")) }