Displaying 20 results from an estimated 5000 matches similar to: "Writing new methods for `names<-`"
2006 Feb 14
3
S4 classes and methods with optional arguments
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",
2009 Oct 31
3
Plots with k-means
Hi,
I'm doing a k-means cluster with 6 clusters and 15 variables. Any
suggestions on how to plot the results?
I've tried the standard xy plot, but couldn't get much of it.
Thansk in advance,
Iuri.
2013 Feb 14
4
2 setGeneric's, same name, different method signatures
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
2010 Sep 03
3
S4 Method Signatures
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 =
2006 Oct 19
1
default arguments in generics and methods
i believe the following is true but would appreciate confirmation
that it is intended behavior and will continue:
if a default argument is employed in the definition of a generic
function, and the generic is called with the argument in question
(call it 'ARG') missing, then the method for signature (..., ARG =
"missing", ...) will be called by 'standardGeneric'
2009 Jun 05
2
Problem with generic methods
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":
2005 Jul 20
1
Default arguments for setMethod() (PR#8021)
Full_Name: Bert Gunter
Version: 2.1.1
OS: Windows 2000
Submission from: (NULL) (192.12.78.250)
There appears to be either a bug or documentation problem in
setMethod/setGeneric with how default arguments are handled. The setMethod Help
says:
******
Method definitions can have default expressions for arguments. If those
arguments are then missing in the call to the generic function, the default
2008 Mar 13
3
Sealed for setGeneric
Hi the list
When two setGeneric occurs on the same function, the second erage the
first and erase all the function previously define.
Is it possible to prevent that ? Is it possible to declare a setGeneric
that can not be erased later ?
Something like the |sealed for setMethod...|
||
|Thanks|
||
Christophe
2008 May 10
2
Hashes as S4 Classes, or: How to separate environments
For learning purposes mainly I attempted to implement hashes/maps/dictionaries
(Python lingua) as S4 classes, see the coding below. I came across some rough S4
edges, but in the end it worked (for one dictionary).
When testing ones sees that the dictionaries D1 and D2 share their environments
D1 at hash and D2 at hash, though I thought a new and empty environment would be
generated each time
2011 Aug 23
1
Implementing a "plugin" paradigm with R methods
Dear list,
I was wondering how to best implement some sort of a "plugin" paradigm
using R methods and the dispatcher:
Say we have a function/method ('foo') that does something useful, but
that should be open for extension in ONE specific area by OTHERS using
my package. Of course they could go ahead and write a whole new 'foo'
method including the features they'd
2010 Mar 15
2
Strange behavior of assign in a S4 method.
Hi the list,
I define a method that want to change an object without assignation
(foo(x) and not x<-foo(x)) using deparse and assign.
But when the argument of the method does not match *exactly* with the
definition of the generic function, assign does not work...
Anything wrong?
Christophe
#------ Does not work ------#
2009 Oct 27
1
How to reduce key strokes when defining S4 classes?
I feel tedious when I define a S4 class and the methods. For each
method, I have to call both setMethod and setGeneric (or both
setReplaceMethod and setGeneric). I would like a more compact grammar
so that I can reduce the key strokes. I'm wondering if there is a
better way available.
setClass(
Class='A',
representation=representation(
x='numeric'
)
2006 Oct 11
1
dispatching on group generics with more than one formal
please see the code below. foo2 fails to dispatch correctly, but foo
does fine. i have tried 'cacheMetaData(1)' and a number of different
variants of 'cacheGenericsMetaData', on the possibility there is a
caching issue. but i still can't sort it out.
also one general question: does it really matter what's in the body
of the function definition in a
2006 Jan 25
2
Using substitute from inside an S4 method
Hi all,
I would like to access the name of a variable passed to an S4 method.
For a function, I would do this:
f <- function(x) as.character(substitute(x))
This also works for a the examples I have tried for methods that do
not have extra, non-dispatch args:
setGeneric("A", function(x, ...) standardGeneric("A"))
setMethod("A",
2006 Mar 22
1
setting argument defaults in setMethod
Hi,
I want to set a default value in a method of a generic function. This seems
as though it should be possible. From R help on setMethod...
Method definitions can have default expressions for arguments. If
those arguments are then missing in the call to the generic
function, the default expression in the method is used. If the
method definition has no default for the
2005 Mar 25
1
S4 methods semantics questions
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
2008 Jan 22
1
deparse, substitute and S4 generics
Hello everyone,
I encountered the following confusing behavior of 'deparse' and
'substitute' while programming with S4 classes (see example below). It
seems like the presence of '...' argument in the definition of the
generic generates the problem. I have no clue why, can anyone explain
that to me? Are there any "workarounds"?
Thanks a lot for your time!
2005 Dec 29
1
trouble with S4 methods for group "Summary"
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")
2007 Apr 19
2
setClass inside a function
Hello,
I would like to create a function that gets passed a class name and then calls setClass, and a few other functions, inside. I have done this in the past with setmethod, creating accessors for all slots in a set of S4 classes. But setClass is choking when my function is called isnide a package, telling about an error in exists(cname, where). I assume this to be a problem with the
2005 Jan 19
2
signif() generic
Dear list,
I'm trying to write a class for Gaussian error propagation of measured
values and their (estimated) errors,
> setClass("sec", representation(val="numeric", err="numeric"))
I've already successfully implemented basic arithmetics using mostly the
"Arith" group generics. But I'm running into trouble when trying to get
signif() to