Displaying 20 results from an estimated 6000 matches similar to: "S4 Reference Classes: undesired behavior when calling method '$field()'"
2011 Jun 03
2
Bug or feature: using "ANY" as a generic field class (was: '[R] Is there a (virtual) class that all R objects inherit from?)
Dear list,
I was wondering if you could help me out in clarifying something:
Is it possible to use class "ANY" in slots/fields of formal classes if you
a) do not want to restrict valid classes of that field and
b) if you are making explicit use of class inheritance?
It seems to work in simple scenarios but produces errors when class
inheritance comes into play. So I was
2010 Nov 21
1
reference classes: question on inheritance
Dear list,
I have a reference class which should act as a "generic" superclass for
other classes. I've read the respective section at ?setRefClass and put the
name of the superclass to the 'contains' argument of an example subclass
(see class defs below). Classnames are set in a way that shouldn't result in
collation issues (virtual def sourced before superclass def
2011 Mar 07
1
WG: Reference classes: error with missing arguments in method calls
Dear list,
a while ago I posted this at r-devel but got no answers. Hope it?s okay to
give it a shot again by cross-posting it here.
TIA for any comments,
Janko
Von: Janko Thyson [mailto:janko.thyson.rstuff at googlemail.com]
Gesendet: Montag, 21. Februar 2011 00:58
An: r-devel at r-project. org (r-devel at r-project.org)
Betreff: Reference classes: error with missing arguments in method calls
2011 May 27
1
Reference Classes/S4 Classes: can method dispatch check superclasses BEFORE resorting to method for "ANY"?
Dear list,
is it possible that method dispatch checks for superclasses/virtual
classes before checking "ANY"?
I'd like to build a generic initialization method for all my Reference
Class (say "MyDataFrame") objects by having them inherit from class, say
"MyRefClassVirtual" (which would have to be a virtual S4 class; there
are no virtual Reference Classes,
2010 Nov 17
2
Reference classes: accessor functions via 'getRefClass(...)$accessors(...)'
Hi there,
I''d like to choose between an "static" and "dynamic" access of a reference
class field, say ''a''.
myObj <- getRefClass("Blabla")$new()
Static: myObj$a
Dynamic: myObj$a.get() where the function retrieves the data
from a database (or some other location), stores it to a buffer and
2010 Nov 23
1
Reference Classes: removing methods -> implications for objects/instances of that class
Dear list,
just to make sure that I understand 'unregistering' methods for S4 reference
classes correctly:
If I registered a method and want to 'unregister' (i.e. remove) this method
again, objects/instance created of the respective class still feature the
removed method until I do an explicit reassign ('my.instance <-
getRefClass("Classname")$new()'), right?
2011 Jun 06
1
Reference Classes: shortcut like 'isS4' for Ref Classes?
Dear list,
is there a shortcut-function to check whether a class is a Reference
Class or not? There's something like this for S4 classes
('isS4(object)'), but I couldn't find anything regarding Ref Classes.
Currently, I'm doing it this way, which is a bit clumsy:
A <- setRefClass("A", fields=list(X="numeric"))
a <- A$new()
isRefClass <-
2011 Dec 07
1
Possible bug in 'new()' for Reference Classes
Dear list,
I think I stumbled across a little bug with respect to the standard
initialization routine for Reference Classes.
It seems that a field 'self' is treated as if it's name would be '.self'
(which we know is reserved for the self reference of the instantiated
object itself) and thus an error is thrown.
If the field value is assigned in an explicit call after the
2011 Aug 30
1
Why does loading saved/cached objects add significantly to RAM consumption?
Dear list,
I make use of cached objects extensively for time consuming computations
and yesterday I happened to notice some very strange behavior in that
respect:
When I execute a given computation whose result I'd like to cache (tried
both saving it as '.Rdata' and via package 'R.cache' which uses a own
filetype '.Rcache'), my R session consumes about 200 MB of
2011 May 04
1
Reference Classes: replacing '.self' with an .Rda image of '.self' from within a method? (was replacing '.self' with an .Rda image of '.self' from within a method?)
Sorry guys,
but I chose a really stupid name before (no "reference classes").
Hope it's okay to re-post.
Cheers,
Janko
>>> ORIGINAL MESSAGE <<<
Dear list,
Is it possible to update or reassign '.self' with an image of '.self'
(e.g. a locally stored .Rda file) from within a method?
I know that this might sound akward, but here's the use
2012 Jun 18
1
S4 Reference Classes: declaring public and private methods
Dear list,
is there a way to declare public and private methods in S4 Reference
Classes? If not, are there plans to add such a feature?
You'll find a small code example of what I mean at Stackoverflow:
http://stackoverflow.com/questions/11073253/oop-with-r-is-there-a-way-to-declare-public-and-private-methods-s4-reference-c
Thanks a lot,
Janko Thyson
2011 Jun 06
1
How can I write methods for 'as()'?
Dear list,
I wonder how to write methods for the function 'as' in the sense that I
can call 'as(object, Class, strict=TRUE, ext)' and let method dispatch
figure out the correct method.
AFAIU, there is a difference between, e.g. 'as.data.frame' and the
methods of 'as()' as stated above since the former depends on arg 'x'
instead of 'object',
2010 Nov 24
2
Reference Classes: how to clone/copy instances?
Dear list,
I don't know what's the correct term for this in the OOP context, but is it
possible to "clone"/copy an instance of a reference class (say 'a') so that
I get an *autonomous* second instance 'b'? Autonomous in the sense that
changes to 'a' do not affect 'b'.
I know that this is somewhat against the pass-by-reference paradigm, but the
2011 Jun 29
1
Ref Classes: bug with using '.self' within initialize methods?
Dear list,
I'm wondering if the following error I'm getting is a small bug in the
Reference Class paradigm or if it makes perfect sense.
When you write an explicit initialize method for a Ref Class, can you
then make use of '.self' WITHIN this initialize method just as you would
once an object of the class has actually been initialized?
Because it seems to me that you can not.
2014 Nov 27
2
Feature request: mixing `...` (three dots) with other formal arguments in S4 methods
Hi Gabriel,
and thanks for answering. I'm basically just trying to find a way to use
the power of `...` in more complex scenarios and I'm well aware that this
might not be the best approach ;-)
Regarding your actual question:
"Are you suggesting methods be dispatched based on the *contents* of ...
[...]?"
Yes, I guess currently I kind of do - but not on the argument *names*
2014 Nov 27
2
Feature request: mixing `...` (three dots) with other formal arguments in S4 methods
Dear List,
I'm currently investigating if the argument dispatch mechanism based on
`...` could somehow be "generalized" to scenarios that involve `r`
recipients located across `c` calling stack layers *and* combined with the
S4 method mechanism (for those interested see
2014 Nov 28
1
Feature request: mixing `...` (three dots) with other formal arguments in S4 methods
Well, the benefit lies in the ability to pass along arguments via `...` to
more than one recipient that use *identical argument names* and/or when
these recipients are not necessarily located on the same calling stack
layer.
I'm *not* after a *general* change in the way arguments are
dispatched/functions are called as I'm actually a big friend of keepings
things quite explicit (thus
2011 Feb 16
2
Avoiding name clashes: opinion on best practice naming conventions
Dear List,
I'm trying to figure out some best practice way with respect to the naming
conventions when building own packages.
I'd like to minimize the risk of choosing function names that might
interfere with those of other packages (both available ones and those yet to
come).
I came up with following alternatives
1. Prefixing the actual names (e.g. myPkgfoo() instead of foo()): pretty
2012 Jul 30
1
Possible bug in class 'POSIXlt' when including microseconds?
Dear list,
I'm a bit puzzled by an ambiguity with respect to the representation of
micro-/milliseconds when using 'POSIXlt' objects.
It seems that the last digit of the 'sec' attribute sometimes seems to
differ from the digits shown when printing the 'POSIXlt' object. You'll
find a little SO post with some example code here:
2011 May 26
1
Is it possible to define a function's arguments via a wildcard in 'substitute()'?
Dear List,
just out of pure curiosity: is it possible to define a function via
'substitute()' such that the function's formal arguments are specified
by a "wildcard" that is substituted when the expression is evaluated?
Simple example:
x.args <- formals("data.frame")
x.body <- expression(
out <- myArg + 100,
return(out)
)
expr <-