[R] Problem with generic methods

[Uwe Ligges]

Rainer M Krug wrote:
> Hi
> 
> I want to create a new generic method, but I end up with an error
> (evaluation nested too deeply). see the transcript below.
> The function beginYear.Fun() works, but not beginYear.
> 
> I have no idea why.
> 
> Any ideas welcome,
> 
> Rainer
> 
> 
>> setClass("fun", representation(x = "numeric"))
> [1] "fun"
>> new("fun")
> An object of class “fun”
> Slot "x":
> numeric(0)
> 
>> setGeneric(
>            "beginYear",
>            function(object, ...) standardGeneric("beginYear")
> )
> setGeneric(
> +            "beginYear",
> +            function(object, ...) standardGeneric("beginYear")
> + )
> [1] "beginYear"
> 
>> beginYear.Fun = function(x) x^2
>> beginYear.Fun(4)
> [1] 16
> 
>> setMethod(
>           "beginYear",
>           signature( object = "numeric" ),
>           beginYear
>           )
> setMethod(
> +           "beginYear",
> +           signature( object = "numeric" ),
> +           beginYear
> +           )
> [1] "beginYear"


.... because the method function you want to call is beginYear.Fun 
rather than beginYear as declared in the method specification?

Uwe Ligges


>> beginYear.Fun(4)
> [1] 16
> 
>> beginYear(4)
> Error: evaluation nested too deeply: infinite recursion / options(expressions=)?
>