similar to: Methods overview

(1) It seems to me that, generally, in R it is not possible to overload functions. Is that right? (2) Assuming that the above is true, or partially true, is there any extra packages to handle overloading in R? (3) Assuming (1) is TRUE and (2) is FALSE, can anyone provide some advice on developing some function that understand what the arguments are and then calls the right overloaded

Hi, i have used S4 classes to implement a unified access to random number generators (package rstream on CRAN). I have used a construct to allow optional arguments: if(!isGeneric("rstream.sample")) setGeneric("rstream.sample", function(stream,...) standardGeneric("rstream.sample")) setMethod("rstream.sample",

Folks: This is a question about the S4 formal class system. Suppose I have a class, 'foo', defined by: setClass('foo',representation(dat='matrix', id='character') ) I wish to define a '[' method for foo that will extract from the 'dat' slot. I would have thought that the following would work, but it doesn't:

Hello. This question concerns the Methods package. I have created a new class and am trying to set a method for it for S4 group generic "Summary". I have run into some signature problems. An example: > setClass("track", representation(x="numeric", y="character")) [1] "track" > setGeneric("max", group="Summary")

Some quick questions about S4 methods. Does the typing of S4 methods mean that lazy evaluation is no longer possible? It seems that you would need to evaluate the arguments to determine their type at dispatch. Second, what role, if any, do default arguments play in S4 methods? I notice that you can put default arguments into generics but that the dispatch is still done on the type of the

Hi I want to create a new generic method, but I end up with an error (evaluation nested too deeply). see the transcript below. The function beginYear.Fun() works, but not beginYear. I have no idea why. Any ideas welcome, Rainer > setClass("fun", representation(x = "numeric")) [1] "fun" > new("fun") An object of class ?fun? Slot "x":

There seems to be a bug arising when using multiple S4 generics with "..." as the signature. The following code works as expected: ############################################################## > setGeneric("rbind", function(..., deparse.level=1) standardGeneric("rbind"), + signature = "...") Creating a generic for "rbind" in

Hi the list I am creating a package and I have a problem to define a S4 method for plot. I define a class 'A' and a class 'B'. I want to define a function plot for signature c(A,missing) and another method plot for signature c(A,B). My code is the following : In /package/R/ directory: --- main.R --- setGeneric("plot",function(x,y,...){standardGeneric("plot")})

Hi R people: I would like to learn about classes, methods, S3 and S4. Which book would be the most helpful for this info, please: the green one or the white(and blue) one? Or is there something that would be even better, please? Thanks in advance. Sincerely, Laura Holt mailto: lauraholt_983 at hotmail.com R 2.1.0 Windows. trying to learn

I attempted to fix it, and that example seems to work for me. It's also a (passing) regression test in R. Are you sure you're using a new enough R-devel? On Tue, Apr 25, 2017 at 2:34 AM, Andrzej Ole? <andrzej.oles at gmail.com> wrote: > Hi Michael, > > thanks again for your patch! I've tested it and I'm happy to confirm that > `callNextMethod()` works with

Thanks I think you have both answered my question (reckon Ill go S3 on that). As an adjunct to this do you know what might be the best reference to the S4 methods current implementation. I have ordered the Chambers book "Programming with Data", and I have a short tutorial-- "S4 Classes in 15 pages, more or less". Have I missed any other useful resources? Stephen Henderson

I ported that over. On Tue, Aug 1, 2017 at 5:50 AM, Andrzej Ole? <andrzej.oles at gmail.com> wrote: > Thank you Michael for updating the 3.4 branch, the `callNextMethod()` now > works for `...` methods as expected. However, I'm still missing your other > patch fixing the handling of arguments in `...` methods. It would be really > great if this bugfix could be integrated

Hello. I am trying to write an S4 method for rbind(). I have a class of objects called 'mdm', and I want to be able to rbind() them to one another. I do not want the method for rbind() to coerce anything to an mdm object. I want rbind(x1,x2,x1,x2) to work as expected [ie rbind() should take any number of arguments]. This is what I have so far: setGeneric(".rbind_pair",

Hi all: we have noticed for quite a while that certain errors cannot be handled by R try, tryCatch etc blocks, but it was fairly difficult to understand what were the conditions for this incorrect behaviour. Finally I stabbed across a very understandable case, which is outlined in the (runnable) example below. The main message is: wrapping an S4 method call in a try block will not help if an

Hi I am having difficulty with setMethod(). I have a "brob" class of objects whose representation has two slots: "x" and "positive". Slot "x" (double) holds the log of a number and slot "positive" (logical) its sign. The idea is that large numbers can be handled. I'm trying to implement a log() method using an analogue of the

I've installed R-devel R Under development (unstable) (2014-07-09 r66111) Platform: x86_64-apple-darwin13.1.0 (64-bit) and am trying to resolve some problems that I am seeing with my SparseM package. In prior versions I explicitly had: setGeneric("image", function(x, ...) standardGeneric("image")) and then used setMethod to define a method for the class matrix.csr but

Dear List, I'm struggling with the signature writing cbind/rbind functions for a S4 class. First of all, I'm very happy that it is now possible to dispatch on ... I follow the example for "paste" in ?dotMethods, which works as far as this: ### start example setClass ("cbtest", representation = representation (data = "data.frame"),

Hi, I was wondering if there was a way to store the results of a computationally expensive "getter" call on an S4 object, so that it is only calculated once for each object. Trivial example: let's say I want to cache the "expensive" area calculation of a square object. setClass("Square", representation( length='numeric',

hi. below is a small test case (hopefully minimal, though i'm still a bit confused about initializers). i would have guessed (and maybe i still would have been right) that one could re-use the name of a generic function for functions with different numbers of arguments. in the case below, class A's bB() queries the status of a single A object, so bB(A) (where here "A" is an

Hello, If the signature of a method defines which generic it implements then I'm confused about why this minimal example I invented won't work : setGeneric("myFun", function(rs, ...){standardGeneric("myFun")}) setGeneric("myFun", function(cs, ...){standardGeneric("myFun")}) setMethod("myFun", "numeric", function(rs, colour =