similar to: S4 Slot assignment within function

Dear R-users, I am working on a project that uses S4-classes. At some point I encountered the problem - well known to R - that I have to pass 3 different objects to a function, that should modify several slots of them and of course there is no passing by reference in R. Then I read this thread by Steve Lianoglou: https://stat.ethz.ch/pipermail/r-help/2010-August/250468.html, which offers from

Dear all, I have an S4 class with a slot "extra" which is a list. I want to be able to add an element called "name" to that list, containing the object "value" (which can be a vector, a dataframe or another S4 object) Obviously setMethod("add.extra",signature=c("PM10Data","character","vector"), function(object,name,value){

Apologies for asking something that is probably very obvious, i just started with S4 classes and i guess i am not finding documentation that lays out the grammar rules and gives enough examples. I understand that main method of writing a member function is to write a generic function and setMethod for this particular class. This, however, presumes that there is "virtuality" for this

Hi R friends,   I'm still studying S4 classes and I have a question about slot assignment. Why would I have to use a special setter method [example 2 below] if I can assign data to a slot directly when I call new() [example 1 below]?   ## first way to do it (the idiosyncratic way?) setClass(Class = "TestClass", representation = representation(myDf = "data.frame"))

Apologies for asking something that is probably super obvious, i just started with S4 classes and i guess i am not finding documentation that layout the grammar rules and give enough examples. Some questions i am having are these 1. I understand that main method of writing a member function is to write a generic function and setMethod for this particular object. This, however, presumes that there

Dear list, I noticed something while assigning a new value to the slot of an object of class S4. Apparently(*) this object is copied while the operation is performed. Is it really wished ? (or did I miss something ?) I use R-1.6.2: > R.version _ platform i686-pc-linux-gnu arch i686 os linux-gnu system i686, linux-gnu status

Hello Apologies for cross-posting, the discussion should (if) go to R-devel, but I also want to reach the rcpp-devel people. My C++ class FOO is a module available through Rcpp, and it works fine and is -- so far -- bug free. With trying to further develop my R package, I thought it was a good idea to interface my C++ workhorse FOO with an S4 class Foo. After some long and not always insightful

Dear R-developers I came across the following issue, which I find strange: setClass("A", representation(a = "numeric")) B <- list() myA <- new("A", a = 1) B$otherA <- myA B$otherA at a <- 2 myA at a Assigning a new value to slot 'a' in the _copy_ of myA stored in B$otherA changes the original value of myA -- this was surprising to me, and I

All, I am considering creating an S4 class whose slots (2) are both S4 classes. ?Since an S4 slot can be an S3 class I figure this can be done. ?However, the correct syntax of which I am unsure. ?Reviewing the docs I have come to the following conclusion: SetClass('myfoo', ? ? ? ? ? ? ? ? ? slots = (foo1, foo2)) Without a type I believe each slot is .Data. ?A get method on the above

Dear all, Since my package is based on S4 classes, I would like to know how to add a slot to an existing S4 class without breaking the code of users of my package. Assume the following S4 class: setClass("MyClass", representation(name = "character", type = "character", data = "data.frame" ), prototype(name =

How do you debug methods of a reference class? I've been using mtrace, which is excellent, but i cannot figure out how to mtrace a reference class method. Maybe there is some other way to debug these, for example with ordinary trace? for now i am only able to use options(error=recover), which is not giving me idea where exactly in the code i am once i am stopped on an error. -- View this

When I define an S4 class ("B" in the example below) that directly extends another ("A" in the example below) , which in turn directly extends another ("character" in the example below), I find that the slot does not have the class I specified in setClass(), it has the underlying class. Is this an intended feature? Briefly, the reason for using this type of

I'm using an S4 object with a slot of type 'call': I would like to be able to initialize it with something like NULL or NA (indicating that there is no information in the slot) but the value should comply with the fact that it must be of type call. Is there any simple way to obtain this? Thanks for any hint, Roberto -- <r/> | Roberto Brunelli - [scientist at Fondazione

Hi, Why doesn't this work? setClass("test",representation(names="character")) tmp <- new("test") tmp@names <- "a" Error in "slot<-"(object, name, TRUE, value) : 'names' attribute [1] must be the same length as the vector [0] Why does this work (replace names with name)?

Dear listmembers, I would like to define a class with a slot that takes either an object of class aov or NULL. I have been reading "S4 Classes in 15 pages more or less" and "Lecture: S4 classes and methods" #First I tried with list and NULL setClass(listOrNULL") setIs("list", "listOrNULL") setIs("NULL", "listOrNULL") #doesn't

Dear all, Assume that I have an S4 class "MyClass" with a slot "myname", which is initialized to: myname="" in method("initialize"): myclass <- new("MyClass", myname="") Assume that class "MyClass" has a method "mymethod": "mymethod.MyClass" <- function(object, myname=character(0), ...) {

Hi, It's nice to be able to define S4 classes with slots that correspond to standard attributes: setClass("A1", slots=c(names="character")) setClass("A2", slots=c(dim="integer")) setClass("A3", slots=c(dimnames="list")) By doing this, one gets a few methods for free: a1 <- new("A1", names=letters[1:3])

What is the Rd file alias and usage syntax for an S4 assignment method? I have been trying variations on \alias{TSdoc<-,default-method} \usage{ \S4method{TSdoc}{default}(x) <- value but so far I have not got it right according to various codoc, etc, checks. Paul Gilbert ==================================================================================== La version fran?aise

Hi How do I specify an S4 class with a slot that is potentially numeric, but NA by default? I want the slot to be NA until I calculate its value (an expensive operation, not needed for all applications). When its value is known, I will create a new object with the correct value inserted in the slot. I want "NA" to signify "not known". My attempt fails because

I have an S4 class with a slot of class "array", and in upgrading to 2.0.1 (from 1.9.1) I have encountered a change in behaviour. This causes me some difficulties if I want to allow 2-dimensional arrays in the slot. The following (in 2.0.1) illustrates the point: > setClass("foo",representation("array")) [1] "foo" > a <-