It would be nice to be able to trigger NA returning NA with an argument to the function, but you can easily get that result:
> ifelse(is.na(x), NA, nzchar(x)) [1] TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE [13] TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE [25] TRUE TRUE NA FALSE ---------------------------------------------- David L Carlson Associate Professor of Anthropology Texas A&M University College Station, TX 77843-4352 > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-bounces@r- > project.org] On Behalf Of Bert Gunter > Sent: Monday, August 06, 2012 10:43 AM > To: Liviu Andronic > Cc: r-help@r-project.org Help > Subject: Re: [R] issue with nzchar() ? > > Liviu: > > Well, as usual, to a certain extent this is arbitrary and the only > issue is whether it is documented correctly. > > To me, NA (of whatever mode) means ""indeterminate" or "unknown," so > since "" is known and of length 0, I would have expected NA as a > return. But the point is, not what our particular tastes are ("You say > 'tomayto', I say 'tomahto,' an old song goes), but what the docs say. > And in both cases, they tell you exactly what you'll get. > > For nchar(): " an integer vector giving the sizes of each element, > currently always 2 for missing values (for NA)" > > and for nzchar: "a logical vector of the same length as x, true if and > only if the element has non-zero length." (note the 'only if'). > > So I see no error or inconsistencies anywhere. > > -- Bert > > On Mon, Aug 6, 2012 at 7:53 AM, Liviu Andronic <landronim...@gmail.com> > wrote: > > On Mon, Aug 6, 2012 at 4:48 PM, Liviu Andronic > <landronim...@gmail.com> wrote: > >> string, something that I find strange. At best NA is the equivalent > of > >> an empty string. In this sense, if you Hmisc::describe() the vector > >> you get, as I would expect, that in the context of character vectors > >> NA and '' values are considered together: > >> > > > > By the way, same question holds for nchar(): Should NA values be > > reported as 2-char strings, or as 0-char empty/missing values? > >> x <- c(letters, NA, '') > >> nchar(x) > > [1] 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 0 > > > > > > Liviu > > > > ______________________________________________ > > 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. > > > > -- > > Bert Gunter > Genentech Nonclinical Biostatistics > > Internal Contact Info: > Phone: 467-7374 > Website: > http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb- > biostatistics/pdb-ncb-home.htm > > ______________________________________________ > 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. ______________________________________________ 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.
