Accordng to the S4groupGeneric page, there is no such group. My guess as to why:
Those operators are not S3 generic in R, and S4 dispatch is piggy-backed on S3 dispatch (not necessarily, but for convenience). On Fri, 1 Sep 2006, Robin Hankin wrote: > Hi > > > In V&R the "polynomial" class is explicitly specified to have no > logical operators: > > setMethod("Logic", signature(e1="polynomial"), function(e1,e2){stop > ("...")}) > > > I too have a class of objects for which I want to > specify that Logic operators do not work, but executing > > > > setClass("brob", > representation = representation > (x="numeric",positive="logical"), > prototype = list(x=numeric(),positive=logical()) > ) > > setMethod("Logic",signature(e1="brob"), function(e1,e2) > { > stop("No logic currently implemented for brob objects") > } > ) > > > gives me > > > Error in setMethod("Logic", signature(e1 = "brob"), function(e1, e2) { : > no existing definition for function 'Logic' > > > ?Math seems to imply that there is no "Logic" group. > > So, what is the correct way to specify that logical operations are > not allowed for "brob" objects? > > > > > > -- > Robin Hankin > Uncertainty Analyst > National Oceanography Centre, Southampton > European Way, Southampton SO14 3ZH, UK > tel 023-8059-7743 > > ______________________________________________ > R-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel > -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel