You persist in failing to read the docs! Moreover, neither Hadley Wickham, nor anyone else, is the authoritative source for R usage (other than for the (many!) packages he, himself has authored). R's Help pages and manuals -- and ultimately the source code -- are the only such source.
?factor says in its very first line: "The function factor is used to encode a **vector** as a factor (the terms ‘category’ and ‘enumerated type’ are also used for factors)...." (emphasis added) and: > f <- factor (letters[1:3]) > f [1] a b c Levels: a b c > attributes(f) $levels [1] "a" "b" "c" $class [1] "factor" > is.vector(f) [1] FALSE > attributes(f) <- NULL > f [1] 1 2 3 > is.vector(f) [1] TRUE Don't you think it's time to call a halt to this? Cheers, Bert Bert Gunter Genentech Nonclinical Biostatistics (650) 467-7374 "Data is not information. Information is not knowledge. And knowledge is certainly not wisdom." Clifford Stoll On Thu, Dec 25, 2014 at 2:45 PM, Mike Miller <mbmille...@gmail.com> wrote: > On Thu, 25 Dec 2014, Mike Miller wrote: > >> I was going to ask a question about it how to test that an object is a >> vector, but then I found this: >> >> "is.vector() does not test if an object is a vector. Instead it returns >> TRUE only if the object is a vector with no attributes apart from names. Use >> is.atomic(x) || is.list(x) to test if an object is actually a vector." >> >> From here: >> >> http://adv-r.had.co.nz/Data-structures.html#vectors > > > > But here... > > https://stat.ethz.ch/R-manual/R-devel/library/base/html/vector.html > > ...I read, "Note that factors are *not* vectors" (emphasis theirs), yet... > > >> d <- gl(2,2) > > >> is.factor(d) > > [1] TRUE > >> is.atomic(d) || is.list(d) > > [1] TRUE > >> is.list(d) > > [1] FALSE > >> is.atomic(d) > > [1] TRUE > >> is.vector(d) > > [1] FALSE > > So the factor is not a vector according to R documentation, but it is a > vector according to the Wickham test, and it is not a vector according to > is.vector(). Admittedly, the latter seems not to mean much to the R > experts. Maybe a factor is just a vector with additional attributes. > > Mike ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.
