similar to: Is it possible to simply the use of NULL slots (or at least improve the help files)?

Hi Martin, Thankyou for your response. I suspect that we're not going to agree on the main point. Making it trivially simple (as say Java) to set slots to NULL. So, I'll move on to the other points here. ***Note that cited text uses excerpts only.*** > setClassUnion("character_OR_NULL", c("character", "NULL")) > A = setClass("A", slots =

I did ?"NULL<tab> at the command line and was lead to ?"NULL-class" and the BasicClasses help page in the methods package. getClass("NULL"), getClass("character") show that these objects are unrelated, so a class union is the way to define a class that is the union of these. The essence of the behavior you would like is

Answering to convey the 'rules' as I know them, rather than to address the underlying issues that I guess you are really after... The S4 practice is to use setOldClass() to explicitly treat an S3 character() vector of classes as an assertion of linear inheritance > x <- structure (sqrt (37), class = c ("sqrt.prime", "numeric") ) > is(x,

Dear John and Seth, dear R-devels, once again the question of method dispatch in S4 -- this time with setClassUnion(); taking up your advice in https://stat.ethz.ch/pipermail/r-devel/2006-April/037200.html https://stat.ethz.ch/pipermail/r-devel/2006-April/037201.html I have been too quick in stating that >setClassUnion()---at least in my case---solves the problem; > The problem arises

Some changes to the implementation of S4 classes in the methods package will be committed to the r-devel version, probably later today. They should be largely back-compatible (exception noted below) but they are fairly extensive, so this is an advance notice. The changes form the first of a two-stage change aimed at making the implementation more consistent with R semantics, in particular with

the code below has me confused: setClassUnion("index", c("numeric", "character", "logical")) extends("numeric") # i don't see the class union library(Matrix) extends("numeric") # now i see the class union i am aware that the "Matrix" package separately defines the "index" class union. is it the case that

Hi, I get the following error when trying to remove a union class: > setClassUnion('a', c('matrix', 'numeric')) > removeClass('a') > sessionInfo() R version 2.15.3 (2013-03-01) Platform: i686-pc-linux-gnu (32-bit) locale: [1] LC_CTYPE=en_US.UTF-8 LC_NUMERIC=C [3] LC_TIME=en_US.UTF-8 LC_COLLATE=en_US.UTF-8 [5] LC_MONETARY=en_US.UTF-8

dear all, I try to update my Rversion fro 1.7.1 to 1.8.1 on linux. I have a problem when I try to install pacakges from Bioconductors with : source("http://www.bioconductor.org/getBioC.R") and getBioC(relLevel="release") somme errors append and when I make a library(affy) for example I obtain : > library(affy) Error in setIs("character",

On 03/19/2016 01:22 AM, Michael Lawrence wrote: > > > On Sat, Mar 19, 2016 at 12:10 AM, Herv? Pag?s <hpages at fredhutch.org > <mailto:hpages at fredhutch.org>> wrote: > > On 03/18/2016 03:28 PM, Michael Lawrence wrote: > > > On Fri, Mar 18, 2016 at 2:53 PM, Herv? Pag?s > <hpages at fredhutch.org <mailto:hpages at

On 03/18/2016 03:28 PM, Michael Lawrence wrote: > > On Fri, Mar 18, 2016 at 2:53 PM, Herv? Pag?s <hpages at fredhutch.org > <mailto:hpages at fredhutch.org>> wrote: > > Hi, > > Short story > ----------- > > setClassUnion("ArrayLike", "array") > > showClass("ArrayLike") # no slot > >

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

Hi, Short story ----------- setClassUnion("ArrayLike", "array") showClass("ArrayLike") # no slot setClass("MyArrayLikeConcreteSubclass", contains="ArrayLike", representation(stuff="ANY") ) showClass("MyArrayLikeConcreteSubclass") # 2 slots!! That doesn't seem right. Long story ----------

I am trying to create a class union of class unions to facilitate method dispatch. When I execute code in the global environment, everything acts as expected, however when I put the same code in the context of a package, selectMethod can no longer find the correct method. This first block below puts the code in the context of a package: fn <- "codefile.R" writeLines( c(

Thanks, I'll look into it. On Tue, Feb 18, 2020 at 8:32 AM Ezra Tucker <ezztucker at gmail.com> wrote: > > Hi Robert, > > This looks like a bug to me (tested in R 3.6.2 on Windows), f(new("a")) > should return "hi!". I'll add that this DOES work properly in 3.6.1 > which leads me to suspect this could be due to the subtle change in the > way

Hello, I have a question concerning "setClassUnion". I'm working with R 2.0.0 Patched (2004-10-06) on windows 2000. I tried to use "setClassUnion" in a package I am currently working on. The situation is similar to the following example: The DESCRIPTION file has entries: Depends: R (>= 2.0.0), methods Imports: methods LazyLoad: yes The NAMESPACE file has

Hello, I have a question concerning "setClassUnion". I'm working with R 2.0.0 Patched (2004-10-06) on windows 2000. I tried to use "setClassUnion" in a package I am currently working on. The situation is similar to the following example: The DESCRIPTION file has entries: Depends: R (>= 2.0.0), methods Imports: methods LazyLoad: yes The NAMESPACE file has

Okay - that makes sense and thanks for looking into this! As an aside, from R-devel's perspective would you say methods are stabilizing again or do you foresee a lot of changes coming in the 4.* series? On Tue, Feb 25, 2020 at 3:39 PM Michael Lawrence via R-devel < r-devel at r-project.org> wrote: > This seems to work as expected (returning "hi!") in R-devel, but there

Dear colleagues, there is a behaviour with S4 (virtual) classes that I find very hard to understand: Depending on the position of setAs(), the tree of inheritance changes. This is my baseline example that defines the classes "grandma", "mother", "daughter" and a virtual class "mr_x". For a new instance if "daughter", "mr_x" is betweeen

Dear list: I am looking for a good way to create an S4 class that would extend numeric, but would allow NULL instead of data as well. As far as I can see there is no way at the moment to do that, but please correct me if I am wrong. The best solution I came up with so far was the following (it also indicates a problem of using setClassUnion with numeric as one of the classes): I define a class

Dear all, I have a question regarding setIs and method dispatch in S4 classes: Consider the following example: ##################################################### ## A02 "contains" A01 by setIs: setClass("A01", representation(a="numeric",b="numeric")) setClass("A02", representation(a="numeric",d="numeric"))