[Rd] group generics
Martin Morgan
mtmorgan at fhcrc.org
Wed Nov 25 15:21:32 CET 2009
Hi Ross --
Ross Boylan <ross at biostat.ucsf.edu> writes:
> I have classes A and B, where B contains A. In the implementation of
> the group generic for B I would like to use the corresponding group
> generic for A. Is there a way to do that?
>
> I would also appreciate any comments if what I'm trying to do seems like
> the wrong approach.
>
> Here's a stripped down example:
> setClass("A",
> representation=representation(xa="numeric")
> )
>
> setMethod("Arith", signature(e1="numeric", e2="A"), function(e1, e2) {
> new("A", ax=e1*e2 at xa)
typo, I guess, xa = e1...
> }
> )
>
> setClass("B",
> representation=representation(xb="numeric"),
> contains=c("A")
> )
>
> setMethod("Arith", signature(e1="numeric", e2="B"), function(e1, e2) {
> # the next line does not work right
> v <- selectMethod("callGeneric", signature=c("numeric", "A"))(e1, e2)
v <- callGeneric(e1, as(e2, "A"))
or probably
v <- callNextMethod(e1, e2)
Martin
> print(v)
> new("B", v, xb=e1*e2 at xb)
> }
> )
>
>
> Results:
>> t1 <- new("B", new("A", xa=4), xb=2)
>> t1
> An object of class “B”
> Slot "xb":
> [1] 2
>
> Slot "xa":
> [1] 4
>
>> 3*t1
> Error in getGeneric(f, !optional) :
> no generic function found for "callGeneric"
>
> Thanks.
> Ross Boylan
>
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--
Martin Morgan
Computational Biology / Fred Hutchinson Cancer Research Center
1100 Fairview Ave. N.
PO Box 19024 Seattle, WA 98109
Location: Arnold Building M1 B861
Phone: (206) 667-2793
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