This is one way: f <- function(x, y){ Z <- ifelse(x==y, 3, 4) return(Z) }
DS[3] <- with(DS, f(X,Y)) colnames(DS)[3] <- "Z" But you don't really need a function to do that. DS[3] <- with(DS, ifelse(X==Y, 3, 4)) # this works just fine I'm glad you've decided to use R; eventually you will need to read some intro R manuals. Cheers. flacerdams wrote > > Dear all, > > Suppose I have a dataset with two variables: > > X = c(0, 1, 2) > Y = c(1, 1, 1) > DS = data.frame(X, Y) > > Now, I want to create a new variable Z with 3 observations, but I want its > values to be the result of a function. I want to create a function that > compares X and Y, and if X = Y, then Z value = 3. If X value differs from > Y value, Z value = 4. So, I'd have the following values for Z: 4, 3, 4. > > How can I create a function like that? (Sorry, I know it's a dumb > question, I began to use R two days ago) > > Thank you very much, > > Lacerda > -- View this message in context: http://r.789695.n4.nabble.com/Function-simple-question-tp4536162p4536189.html Sent from the R help mailing list archive at Nabble.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.