similar to: S4 class slot names

Martin, Thanks! I'll use name for now. Steve -----Original Message----- From: Martin Maechler [mailto:maechler at stat.math.ethz.ch] Sent: Thursday, April 13, 2006 3:11 AM To: Steven Lacey Cc: R-bugs at stat.math.ethz.ch; r-help at stat.math.ethz.ch Subject: S4 class slot name 'names' is not allowed >>>>> "SteveL" == Steven Lacey <slacey at

>>>>> "SteveL" == Steven Lacey <slacey at umich.edu> >>>>> on Wed, 12 Apr 2006 19:06:52 -0400 writes: SteveL> Hi, Why doesn't this work? setClass("tests", representation(names = "character")) tmp <- new("tests"); tmp at names <- "a" SteveL> Error in

Hi, This works fine. >setClass("a",representation(b="list",c="list")) >new("a",b=list(7)) >An object of class "a" Slot "b": [[1]] [1] 7 Slot "c": list() But, now suppose you want a slot to accept an object of class formula... >setClass("a",representation(b="list",c="formula"))

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

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

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 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 <-

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 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(),

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 =

Hello, Besides the problem with using "names," one has a similar problem using ".Data" together with "VIRTUAL." Consider the top of p. 295 of the green book. This should work (I had to change "structure" to "junk" because "structure" is a sealed class definition): setClass("junk",

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 <-

can list names attributes be preserved through S4 class containment? seems to be so but only if the containment relationship is direct ... see below. > setClass("c1", contains="list") [1] "c1" > l1 = list(a=1, b=2) > o1 = new("c1", l1) > names(o1) # pleasant surprise [1] "a" "b" > setClass("c2",

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, A small inconsistency (it's probably not even a buglet): > setClass("A", contains="numeric") [1] "A" > names(new("A", c(a=23))) [1] "a" > setClass("B", contains="A") [1] "B" > names(new("B", c(a=23))) NULL > This is exactly that kind of behavior S4 was invented for, you

Hi, I would like to add a key to my trellis plot using draw.key. Here is what I want: 3 x 6 key where the first row is a header. row 1: empty, "S-R Mapping", "R^2" row 2: pch=17, "Color", 0.951 row 2: pch=17, "Shape", 0.934 ect... The problem is that I would like the cell in the upper left corner to be empty (a placeholder) with the remaining

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"))

It seems that if an S4 class has no slots it can't be instantiated because it is assumed to be virtual. Is there a way around this other than adding a do-nothing slot? A singleton would be OK, though is not essential. Problem: EmptyFitResult <- setClass("EmptyFitResult", representation=representation()) # also tried it without the second argument. same result. > e <-

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

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