There is not a single definition of
formatMe()
in your message, therefore nothing works for me, not even the very first
version...
Best,
Uwe Ligges
On 23.06.2010 09:16, Daniel Murphy wrote:
R-Devel-ers:
I have an S4 method that simply formats an object:
setGeneric("formatMe", function(x) standardGeneric("formatMe"))
setMethod("formatMe", "ANY", function(x) format(x))
If I issue the above in an R session, then define an S4 class with its own
format method, I get the desired result:
setClass("A",contains="numeric")
[1] "A"
setMethod("format","A", function(x, ...) "Hey Jude")
Creating a new generic function for "format" in ".GlobalEnv"
[1] "format"
a<-new("A",1968)
formatMe(a)
[1] "Hey Jude"
However, if I put the two "formatMe" definitions into a package ("Test"), I
do not get the desired result.
<start new R session>
library(Test)
setClass("A",contains="numeric")
[1] "A"
setMethod("format","A", function(x, ...) "Hey Jude")
Creating a new generic function for "format" in ".GlobalEnv"
[1] "format"
a<-new("A",1968)
formatMe(a)
[1] "1968"
The "disconnect" does not occur, however, if the S4 format method is an S3
incarnation:
setClass("B",contains="numeric",S3methods=TRUE)
[1] "B"
format.B<- function(x, ...) "Don't make it bad"
b<-new("B",1968)
formatMe(b)
[1] "Don't make it bad"
Could the problem be in Test's NAMESPACE file? There is only one line:
exportMethods(formatMe)
Here is Test's DESCRIPTION file:
Package: Test
Type: Package
Title: Testing format
Version: 1.0
Date: 2010-06-22
Author: Dan Murphy
Maintainer: Dan Murphy<snipped>
Depends: methods
Description: Does format in a package work with S4 format method?
License: GPL (>= 2)
LazyLoad: yes
(I would send the Help file, but I don't think that is the problem.)
I am using version 2.11.1 on a Windows Vista machine.
Any guidance would be appreciated. Thank you
Dan Murphy
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