similar to: length of S4

When passing a list as an argument to a function, I find it convenient to attach it in the first line of th function code, then refer to the components as A, B, etc. rather than as list$A, list$B, etc. If I pass a S4 class object, is there a way to "attach" it, or do I have to refer to the slots as object at A, objetc at B, etc.? I could always make copies, A <- object at A

I looked through the documentation and the mailing lists and could not find an answer to this. My apologies if it has already been answered. If it has, a pointer to the relevant discussion would be greatly appreciated. Creating S4 classes containing environments exhibits unexpected behavior/features.? These have a different in two ways: 1) slotName for the data: ".xData" instead of

Dear r-help list members, Is there a way to test whether an object is an S4 object? The best that I've been able to come up with is isS4object <- function(object) !(is.null(slotNames(object))) which assumes that an S4 object has at least one slot. I think this is safe, but perhaps I'm missing something. Thanks, John -------------------------------- John Fox Department of

Dear r-help list members, Is there a way to test whether an object is an S4 object? The best that I've been able to come up with is isS4object <- function(object) !(is.null(slotNames(object))) which assumes that an S4 object has at least one slot. I think this is safe, but perhaps I'm missing something. Thanks, John -------------------------------- John Fox Department of

Dear Developers, In current implementation of validity method, objects are first coerced to superclass (slots are striped). Thus, it is not possible to write validity method which would perform some checks on children slots. Say, I want to check if number of slots in a class is equal to "n": setClass("A", representation(a="numeric", n="integer"),

Hey everyone, I would like to develop a package using S4 classes. I have to define several S4 classes that inherits from each others as follow: # A <- B <- C <- D I also would like to define .DollarNames methods for these class so, if I have understood well, I also have to define an old class as follow: # AOld <- A <- B <- C <- D setOldClass(Classes = "AOld")

Hi the list, I define a class 'C' that inherit from two classes 'A' and 'B'. 'A' and 'B' have no slot with similar names. ---------------- setClass( Class="C", contains=c("A","B") ) To define the get operator '[' for class "C", I simply use the get of "A" or "B" (the constante

Hi all, I'm working with the S4-Class system and I have a little problem with Implementing iteration functionality in my S4 class but it don't work: > setClass("foo",representation(bar="list")) > x <- new("foo",bar=list(1,2,3)) >for(e in x) cat(e) invalid type/length (S4/1) in vector allocation But when I extend from a

Hi all, I'm currently programming my first complete package in S4. (thanks to Christophe Genolini for the nice introduction he wrote). I have an object "Data" with a number of slots. One of those slots is "meteo". Now "Meteo" is on itself a class with again a number of slots (like rainfall, temperature,..., you get the picture). I defined the slot

Hello, an S4 class "Foo" is defined with a setter, $. For several reasons, the setter calls a function, .foo.update(). However, bypassing the argument names of the setter does not work. Question 1: Why not and how can I fix this? Question 2: What is the way to define either the function or the setter to modify the original object (not returning the modified copy of it an overwrite the

Hi everybody! I'm creating an object of a S4 class that has two slots: ListExamples, which is a list, and idx, which is an integer (as the code below). Then, I read a data.frame file with 10000 (ten thousands) of lines and 10 columns, do some pre-processing and, basically, I store each line as an element of a list in the slot ListExamples of the S4 object. However, many operations after this

Hi the list, Using S4, how can we create a package? In "S4 Classes in 15 pages, more or less", they put all the classes definition in a function that will be called at the opening of the library and they add "by hand" a Rd file. Is it the only way ? Is there something like "S4.package.skeleton"? Thanks Christophe

Hi the list, I almost finished the green book (chapter 7 and 8 on S4), this is probably one of my last question :-) I hope you will not miss them to much ! Here is my today nighmare: I do not manage to use dumpMethod : setClass("A",representation(a="numeric")) setMethod("plot","A",function(x,y,...){cat("AAAAA\n")})

Hi,   I'm reading up on S4 classes *). There seem to be at least two ways of input validation: setClass() (using the 'validity' argument)  and setValidity(). Is it a matter of taste which function is used? Or should more complex validation code better be put in a setValiditity call? *) A (Not So) Short Introduction to S4 Object Oriented Programming in R V0.5.1 Christophe Genolini

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])

I have been retooling an S4 class definition to include another slot and have found that the methods::validObject function (defined in methods/R/SClasses.R) in R-devel throws an error that isn't caught internally (and thus not controllable by 'test' argument) when retrieving a non-existent slot. The offending line of code is shown below: > validObject function (object, test =

Hi the list I am fighting with the twins setAs and setIs... Here are some questions and comments (comments to myself but that migth be wrong, it is why I am posting them) 1. Very surprising : using setIs define 'is', 'as<-' but not 'as' ??? 2. Using setAs define 'as', 'as<-' but not 'is'... What surprise me is that as<- can be define by

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 the devel list. I am adapting the package.skeleton to S4 classes and methods I would have been very proud to post a new working function on this list. Unfortunately, I do not manage to solve all the problems. Mainly - sys.source does not compile a file with setClass - dumpMethod does not exists yet In the following code, thise two problems are notified by a line ################# Still

Dear R users! Several languages like C# or VB allow one to create properties; typically these are under 'get', 'set' tags. My question is this really, what are similar or comparable strategies in R, and what might be preferred? I have a couple of situations where I want a certain computation to belong to a class, but I do not really want to seperate it out to a stand-alone