[R] S3 vs S4 class

2008-10-07 Thread Terry Therneau 
  
  
  A simple example:
temp - as.Date('2001-10-5')
class(temp)
  Date

How do I tell if Date is implemented as an S3 or an S4 class type?
I tried ?class, but didn't see anything obvious.  Functions like inherit() work
equally well with both types (which is a good thing).

  I expect the answer will be obvious - once someone points it out to me.

Terry T

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Re: [R] S3 vs S4 class

2008-10-07 Thread Duncan Murdoch 

On 07/10/2008 10:41 AM, Terry Therneau wrote:
  
  
  A simple example:

temp - as.Date('2001-10-5')
class(temp)
  Date

How do I tell if Date is implemented as an S3 or an S4 class type?
I tried ?class, but didn't see anything obvious.  Functions like inherit() work
equally well with both types (which is a good thing).

  I expect the answer will be obvious - once someone points it out to me.


You could use the isS4 function:

 temp - as.Date('2001-10-5')
 isS4(temp)
[1] FALSE

Duncan Murdoch

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