Modelling a mutable entity, i.e. an account, is really a perfect example of when to use reference classes. You might find the examples on http://adv-r.had.co.nz/OO-essentials.html give you a better feel for the strengths and weaknesses of R's different OO systems.
Hadley On Sat, Nov 9, 2013 at 9:31 AM, daniel schnaider <dschnai...@gmail.com> wrote: > It is my first time programming with S4 and I can't get the setter fuction > to actually change the value of the slot created by the constructor. > > I guess it has to do with local copy, global copy, etc. of the variable - > but, I could't find anything relevant in documentation. > > Tried to copy examples from the internet, but they had the same problem. > > # The code > setClass ("Account" , > representation ( > customer_id = "character", > transactions = "matrix") > ) > > > Account <- function(id, t) { > new("Account", customer_id = id, transactions = t) > } > > > setGeneric ("CustomerID<-", function(obj, > id){standardGeneric("CustomerID<-")}) > setReplaceMethod("CustomerID", "Account", function(obj, id){ > obj@customer_id <- id > obj > }) > > ac <- Account("12345", matrix(c(1,2,3,4,5,6), ncol=2)) > ac > CustomerID <- "54321" > ac > > #Output > > ac > An object of class "Account" > Slot "customer_id": > [1] "12345" > > Slot "transactions": > [,1] [,2] > [1,] 1 4 > [2,] 2 5 > [3,] 3 6 > > # CustomerID is value has changed to 54321, but as you can see it does't > > CustomerID <- "54321" > > ac > An object of class "Account" > Slot "customer_id": > [1] "12345" > > Slot "transactions": > [,1] [,2] > [1,] 1 4 > [2,] 2 5 > [3,] 3 6 > > > Help! > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. -- Chief Scientist, RStudio http://had.co.nz/ ______________________________________________ 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.