On Thu, 2005-08-18 at 17:30 -0500, Paul Roebuck wrote: > On Thu, 18 Aug 2005, Ross Boylan wrote: > > > setClass("B", representation=representation("B", extra="numeric")) > > setClass("B", representation=representation(extra="numeric"), > > contains="B") > > Are these the same? If not, how do they differ? > > > > What about > > setClass("B", representation=representation("B", extra="numeric"), > > contains="B") > > ? > > > > As far as I can tell, the Green Book doesn't talk about a contains > > argument to setClass. > > "S4 - Composition and Inheritance" by Witold Eryk Wolski > (a.k.a. Extending.pdf) might be what you're looking for.
Thank you. It speaks directly to this question, and asserts that the first two forms are equivalent. contains makes it a bit easier for the eye to catch that inheritance is happening. ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html