[R] Inheriting from factors + co.

[Uwe Ligges]

Torsten Steuernagel wrote:

> On 24 Feb 2004 at 21:38, Uwe Ligges wrote:
> 
> 
>>>setClass("myclass", representation("ANY", x = "numeric", y
>>>="numeric"))
>>>
>>>new("myclass", 1:10)            # works
>>>new("myclass", "Test")          # works
>>>new("myclass", factor(1:10))    # fails
>>
>>Why do you think it fails?
> 
> 
> I was typing faster than thinking. It doesn't actually fail but what I get is 
> a numeric vector with a levels attribute. If I specify a factor as .Data 
> part I expect that the created object IS a factor and 
> is.factor(new("myclass", factor(1:10))) returns TRUE.


So you are going to handle/mix the S4 class like/with S3 classes?
Hmm. It can be either of class "myclass" or of class "factor".
I'd define a separate explicit slot for such a class:

   setClass("myclass", representation(mainSlot = "ANY",
       x = "numeric", y = "numeric"))

John Chambers might want to correct me...

Uwe



> 
>>It works perfectly for me with R-1.8.1 for Windows.
>>You haven't told anything about your R version, I suspect your are
>>using an outdated one.
> 
> 
> Sorry, forgot that one. I'm also using R 1.8.1 on Windows.
> 
> Thanks,
> 
> Torsten
> 
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