similar to: creating objects with a slot of class formula, using new

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)?

Hi, I recently ran into this problem. I couldn't find any mention of it in the setClass documentation. setClass("Foo", representation(file = "character")) setMethod("initialize", "Foo", function(.Object, file) { print(file) }) setClass("Bar", contains = "Foo") And the error: Error in print(file) : argument "file" is

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, I'm trying to make a new S4 object with a slot for a "link-glm" object. R doesn't like me have a slot of class "link-glm" > class(make.link("probit")) [1] "link-glm" > setClass("a",representation(item="link-glm")) [1] "a" Warning message: undefined slot classes in definition of "a": item(class

The documentation for validObject suggests that slots are checked for validity, but validObject seems only to check that the slot has something claiming to be correct; validObject(obj) does not perform the equivalent of validObject(obj at y) for slot y. This is also the second problem issue reported in http://tolstoy.newcastle.edu.au/R/devel/05/03/0151.html Relevant documentation, an example,

Hi, I'm wondering if the following behaviour is normal: setClass('A', representation(number='numeric'), validity=function(object){ if( object at number < -1 ) return("Invalid number"); TRUE}) >[1] "A" a <- new('A') a >An object of class ?A? >Slot "number": >numeric(0) a at number <- 0 a at number <- -3 a >An

As far as I can tell, there's no trivial way to set arbitrary S4 slots to NULL. Most of the online examples I can find, use setClassUnion and are about 10 years old. Which, in my opinion, is defective. There's nothing "robust" about making something that should be trivially simple, really complicated. Maybe there is a simpler way, and I just haven't worked it out, yet. But

Hi, When called with complete=TRUE, validObject() is supposed to work in a recursive manner. But here is a situation where it doesn't seem to be the case. Let's define a class with a validity method: setClass("PosInts", representation(ii="integer")) setValidity("PosInts", function(object) { if (!all(object at ii > 0))

Hi, But "any" rises some other problems well known from S3. One has "any" for "free" in S3. You don't need S4. . But I know how "if" polluted functions look like in S3. They are hard to understand and to maintain. Hence I am quite happy to use S4. Type-checking is usefull if you program with data. Also if you are on the "C side" of the

Hi! Consider this code. setClass("Ctest" ,representation( test="character" ,bla="character" ,mod="lm" ) ) new("Ctest",test="bla") #This produces an error. #Error in validObject(.Object) : Invalid "Ctest" object: Invalid object for slot "mod" in class "Ctest": got class

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 list, I was wondering if you could help me out in clarifying something: Is it possible to use class "ANY" in slots/fields of formal classes if you a) do not want to restrict valid classes of that field and b) if you are making explicit use of class inheritance? It seems to work in simple scenarios but produces errors when class inheritance comes into play. So I was

Hi, It seems that R_do_slot_assign can change the type of an S4 class slot. For example I have a class setClass("ostream", representation(id = "integer", keepOpen = "logical")) and inside a C-function I was able to assign a RAW vector to the id slot. Is this intentional? I remember reading somewhere that the slot type is guaranteed by R. Maybe this doesn't

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 all, I am having a problem trying to declare a slot representation to hold a file connection. With V2.8.0 I had been using: setClass("Element", representation( [other slots removed], datafileConn = setOldClass(c("file","connection")) ) ) This resulted in a warning but still ran okay. No however with V2.9.0 I am getting

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"),

Hello, Thomas Stabla (statho3@web.de) has already sent this question to R-help, Wed, 12 Nov 2003 21:21:31 +0100, but we are not sure whether we should better post this mail to this audience than to R-help: --------------------------------------------------------------------- We are using S4-classes and want to force a validity check when an object is created. How can this be done, when an

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"))

I would like to add a class to the SparseM package. I have a class "matrix.csr" that describes a matrix in compressed sparse row format, now I would like a class matrix.diag.csr that describes such objects when they happen to be diagonal. The idea is that matrix.diag.csr objects should behave (later in life) exactly like matrix.csr objects, the distinction is only needed in order to

Hi, It doesn't seem that the dispatching algo is finding my coerce method under some circumstances. Let's say I have 2 classes, A and AA and that AA is just a direct extension of A with no additional slots: setClass("A", representation(ii="integer")) setClass("AA", contains="A") I can define a method for coercing my objects to an integer