R help - Jun 2008 - Accessing methods and extending S4 classes of existing packages

Dear all,
I am trying to understand how to access S4 methods after loading a 
package, using the online documentation of getMethod and friends.

This is what I have been trying:
> library(coin)
> findMethods("ApproxNullDistribution")
list()
Warning message:
In findMethods("ApproxNullDistribution") :
  nicht-generische Funktion an findMethods() ?bergeben

whereas in the source of coin I can see the lines: 

setGeneric("ApproxNullDistribution", function(object, ...)
    standardGeneric("ApproxNullDistribution"))

It seems that I am not getting what is going on here. Could anybody
give me a hint?

Greetings


Johannes
-- 
Johannes H?sing               There is something fascinating about science. 
                              One gets such wholesale returns of conjecture 
mailto:johannes at huesing.name  from such a trifling investment of fact.
http://derwisch.wikidot.com         (Mark Twain, "Life on the
Mississippi")

Johannes Huesing <johannes at huesing.name> [Sun, Jun 29, 2008 at
08:13:27AM CEST]:
> Dear all,
> I am trying to understand how to access S4 methods after loading a 
> package, using the online documentation of getMethod and friends.
> 
I am just realizing that the lack of online documentation on S4 methods,
which was lamented so long, has apparently been filled by "How S4 Methods
Work" by John Chambers. So please hang on until I have read this piece 
and will be able to ask more educated questions about that matter.


-- 
Johannes H?sing               There is something fascinating about science. 
                              One gets such wholesale returns of conjecture 
mailto:johannes at huesing.name  from such a trifling investment of fact.
http://derwisch.wikidot.com         (Mark Twain, "Life on the
Mississippi")

Johannes Huesing <johannes at huesing.name> [Sun, Jun 29, 2008 at
08:13:27AM CEST]:
> Dear all,
> I am trying to understand how to access S4 methods after loading a 
> package, using the online documentation of getMethod and friends.
> 
> This is what I have been trying:
> > library(coin)
> > findMethods("ApproxNullDistribution")
> list()
> Warning message:
> In findMethods("ApproxNullDistribution") :
>   nicht-generische Funktion an findMethods() ?bergeben
> 
> whereas in the source of coin I can see the lines: 
> 
> setGeneric("ApproxNullDistribution", function(object, ...)
>     standardGeneric("ApproxNullDistribution"))
> 
> It seems that I am not getting what is going on here. Could anybody
> give me a hint?
It seems like the package authors chose not to export the ApproxNullDistribution
generic method from the package, as seen in the NAMESPACE file of the 
package.

Does it mean that if I want to write personal extensions to the package,
the correct approach is to take the whole package and modify it?
-- 
Johannes H?sing               There is something fascinating about science. 
                              One gets such wholesale returns of conjecture 
mailto:johannes at huesing.name  from such a trifling investment of fact.
http://derwisch.wikidot.com         (Mark Twain, "Life on the
Mississippi")