Right. Shame on me : Friday's tiredness ; I don't know why I stuck on that. Please just consider the main topic of my message, regarding the example of ReferenceClasses (supposing it's appropriate) and sorry for the subsequent question...
----- Message d'origine ---- De : David Winsemius <dwinsem...@comcast.net> À : Marc Carpentier <marc.carpent...@ymail.com> Cc : r-help@r-project.org Envoyé le : Ven 28 janvier 2011, 17h 39min 59s Objet : Re: [R] ReferenceClasses examples {method} On Jan 28, 2011, at 11:05 AM, Marc Carpentier wrote: > Dear help, dear John Chambers, > I'm trying to learn OOP-possibilities in R and I was going through the > documentation 'ReferenceClasses {methods}'. (great work, by the way...) > Reading associated Examples, something bothers me : it seems to me that there > are errors in 'edit' and 'undo' methods. I think that : > - 'undo' should update 'edits' field with : > length(edits) <<- length(edits) - 1 #(and not - 2) > - and for coherence, 'edit' should store modifications in an 'append'-style : > edits <<- c(edits,list(backup)) #as opposed to c(list(backup),edits) > > I hope I'm not wrong. > > As a complementary question, suppose one kept 'c(edits,list(backup))', does > anyone know how todiscard first element(s) of a list? For a vector : > vedits<<-vedits[-1] > But lists can't be selected that way ( edits<<- edits [[-1]] #wrong ) You are confusing "[" and "[[" > ll <- list(a=1,b=2,cc=3) > ll[-1] $b [1] 2 $cc [1] 3 > -- David Winsemius, MD West Hartford, CT ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.