similar to: S4 non-virtual class with no slots?

Thanks, Martin, that (inherit from a virtual class) worked great. I already had a base class created with setUnion, and so this was an easy switch. I had assumed that since inheriting from a class without slots would produce a class without slots the result would still be virtual. Fortunately that's not the case. Ross ________________________________________ From: Martin Morgan

I haven't found much on S4 class redefinition; the little I've seen indicates the following is to be expected: 1. setClass("foo", ....) 2. create objects of class foo. 3. execute the same setClass("foo", ...) again (source the same file). 4. objects from step 2 are now NULL. Is that the expected behavior (I ran under R 2.7.1)? Assuming it is, it's kind of

Using R 2.4, the following fails: setClass("testc", representation(a="ANY")) makeC <- function(myarg) new("testc", a=myarg) makeC() -> Error in initialize(value, ...) : argument "myarg" is missing, with no default On the other hand, this is OK: f <- function(a) g(b=a) g <- function(b) if(missing(b)) "missing" else "valid

setClass("B", representation=representation("B", extra="numeric)) setClass("B", representation=representation(extra="numeric"), contains="B") Are these the same? If not, how do they differ? What about setClass("B", representation=representation("B", extra="numeric"), contains="B") ? As far as I can

I defined an S4 class with a slot i. Then I wrote a regular function that attempted to increment i. This didn't work, apparently because of the general rule that a function can't change the values of its arguments outside the function. I gather there are ways around it, but the Green book admonishes "cheating on the S evaluation model is to be avoided" (p. 190). Thinking that

For those who suggest other ways to do this, I ALREADY HAVE ANOTHER DESIGN SOLUTION, DESCRIBED AT THE END. That being said, I want to know if it's possible to reference a slot in an S4 class from another slot, i.e. I'd like to have the "self.*" semantics of Python so that I can reuse a slot. That is, for various reasons it would be nice to be able to do something like:

I have classes A and B, where B contains A. In the implementation of the group generic for B I would like to use the corresponding group generic for A. Is there a way to do that? I would also appreciate any comments if what I'm trying to do seems like the wrong approach. Here's a stripped down example: setClass("A",

I am trying to use a custom S4 object in my C code and I cannot get the access to its slots working. The following is a toy example, but even this crashes. In R I have: setClass("pd", representation(data="numeric")) x <- new("pd", data=1:5) test <- function(pd.obj) { res <- .C("TestFun", pd.obj) res} test(x) (Of couse

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

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

Hello, I am using R 1.7.1 on a Redhat Linux machine, version 7.3. The following works fine: setClass("ok", representation( "A" = "matrix", "Cmatrix" = "matrix")) new("ok", "A" = diag(4), "Cmatrix" = diag(4)) But the following doesn't work: setClass("notok", representation(

Hello, I don't manage to see if you have already focussed on this point in some previous messages so I post my question: I have a little problem with the S4 style of programming. I tried to formalize my question: please consider the following example that you can run I think: #------------------ setClass("my.class1", representation( my.list =

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

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 <-

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])

Is there any good source of information on how S4 classes (and methods) work from C? E.g., for reading how to read a slot value how to invoke a method how to test if you have an s4 object For writing, how to make a new instance of an S4 object. I've found scattered hints in the archive, including a link to a talk on this subject "I am using C code to create an S4 object based on

Hi all, This feature was throwing me for a loop for quite some time until I played with the names of the slots. Consider exhibit A: ============== setClass("SVM", representation=representation( x='numeric', y='numeric', C='numeric', eps='numeric'), prototype=prototype( x=numeric(),

I've fixed this and will commit soon. Disregard my dim<-() example; that behaves as expected (the class needs a dim<-() method). Michael On Tue, Jun 6, 2017 at 5:16 AM, Michael Lawrence <michafla at gene.com> wrote: > Thanks for the report. The issue is that one cannot set special attributes > like names, dim, dimnames, etc on S4 objects. I was aready working on this >

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 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), ...) {