[R] getting lapply() to work for a new class
mtmorgan at fhcrc.org
Thu Aug 16 00:30:50 CEST 2007
My 2 cents, which might be post-hoc rationalization.
If your class 'is' a list, with additional information, then
and you're ready to go.
On the other hand, if your class 'has' a list, along with other
information, create an accessor
setGeneric("test", function(object) standardGeneric("test"))
function(object) slot(object, "test"))
obj <- new("Test", test=list(1,2,3))
(You could define a generic on 'lapply' and a method that dispatches
to your class, but that implies that Test 'is' a list).
"Pijus Virketis" <pvirketis at hbk.com> writes:
> Thank you.
> When I tried to set as.list() in baseenv(), I learned that its bindings
> are locked. Does this mean that the thing to do is just to write my own
> "lapply", which does the coercion using my "private" as.list(), and then
> invokes the base lapply()?
> -----Original Message-----
> From: Prof Brian Ripley [mailto:ripley at stats.ox.ac.uk]
> Sent: Wednesday, August 15, 2007 5:18 PM
>> As far as I can tell, lapply() needs the class to be coercible to a
>> list. Even after I define as.list() and as.vector(x, mode="list")
>> methods, though, I still get an "Error in as.vector(x, "list") :
>> cannot coerce to vector". What am I doing wrong?
> Not considering namespaces. Setting an S4 method for as.list() creates
> an object called as.list in your workspace, but the lapply function uses
> the as.list in the base namespace. That's the whole point of
> namespaces: to protect code against redefining functions.
> R-help at stat.math.ethz.ch mailing list
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
Bioconductor / Computational Biology
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