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I am trying to use a slot of type formula. But formula isn't a basic datatype. What can I do to create a slot to store objects like formula. Or is it intentional to prohibit storing general S3 objects as slots? If it's intentional to use slots of type S4, how do I turn the S3 class formula into S4 class?

John Paul
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Klaus
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3 Answers3

2

Seems to work for me:

setClass("form", representation(f="formula"))
myForm <- new("form",f=y~x)
myForm
An object of class "form"
Slot "f":
y ~ x

class(myForm@f)
[1] "formula"
James
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  • Thax, this structure was also my first trail, and I got an error "cannot use object of class “formula” in new(): class “Myclass” does not extend that class". But your code works fine. But in general, is there a way to use other S4 classes as slot types? – Klaus Jun 29 '12 at 12:17
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Maybe it helps if you use named arguments in your call to new. S4 classes as slots are supported.

setClass(Class = "B", representation = representation(var1 = "character"))
setClass(Class = "A", representation = representation(var1 = "B"))
b<-new("B",var1="b")
a<-new("A",var1=b)
Karsten W.
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I would like to use a mechanism like

 class B{
    int varb=0;
 }

 class A{
     B classvar;
     A(B var) classvar=var;
 }


 b=new B();
 a=new A(b);

Currently I do it in this way

  setClass(Class = "A",
     representation = representation(var1 = "list")
     )

  setClass(Class = "B",
     representation = representation(var1 = "character")
     )
  b<-new("B","b")
  a<-new("A",list(b))

to save S4 object like a class variable.

Klaus
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