From r.hankin at noc.soton.ac.uk  Wed Jun 27 09:19:37 2007
From: r.hankin at noc.soton.ac.uk (Robin Hankin)
Date: Wed, 27 Jun 2007 08:19:37 +0100
Subject: [Rd] inherits() and virtual classes
Message-ID: <75FA4E14-86B6-4A11-A8B0-B0332C7E1FCB@noc.soton.ac.uk>

Hi

How do I test for an object having a particular virtual class?

In the following, "onion" is a virtual class, and "octonion" is
a non-virtual class contained in onion.  The last call
to inherits() gives FALSE [R-2.5.0], when inherits.Rd led
me to expect TRUE.




setClass("onion",
          representation = "VIRTUAL"
          )

setClass("octonion",
          representation = representation(x="matrix"),
          prototype      = list(x=matrix(numeric(),0,8)),
          contains       = "onion"
          )


jj <- new("octonion",x=as.matrix(1:8))

inherits(jj,"onion")




--
Robin Hankin
Uncertainty Analyst
National Oceanography Centre, Southampton
European Way, Southampton SO14 3ZH, UK
  tel  023-8059-7743



[Rd] inherits() and virtual classes
Robin Hankin