> On 20 Jan 2018, at 07:53 , Suharto Anggono Suharto Anggono via R-help > <r-help@r-project.org> wrote: > > Extremes.Rd, that documents 'max' and 'pmax', has this in "Details" section, > in the paragraph before the last.
> By definition the min/max of a numeric vector containing an NaN is NaN, > except that the min/max of any vector containing an NA is NA even if it also > contains an NaN. ...but how do you infer that this applies to pmin/pmax? You may want it to, but it specifically talks about the non-parallel min/max. -pd > > ------------------ >>>>>> Michal Burda <michal.burda at centrum.cz> >>>>>> on Mon, 15 Jan 2018 12:04:13 +0100 writes: > >> Dear R users, is the following OK? > >>> max(NA, NaN) >> [1] NA >>> max(NaN, NA) >> [1] NA >>> pmax(NaN, NA) >> [1] NA >>> pmax(NA, NaN) >> [1] NaN > >> ...or is it a bug? > >> Documentation says that NA has a higher priority over NaN. > > which documentation ?? > [That would be quite a bit misleading I think. So, it should be amended ...] > >> Best regards, Michal Burda > > > R's help pages are *THE* reference documentation and they have > (for a long time, I think) had : > > ?NaN has in its 3rd 'Note:' > > Computations involving ‘NaN’ will return ‘NaN’ or perhaps ‘NA’: > which of those two is not guaranteed and may depend on the R > platform (since compilers may re-order computations). > > Similarly, ?NA contains, in its 'Details': > > Numerical computations using ‘NA’ will normally result in ‘NA’: a > possible exception is where ‘NaN’ is also involved, in which case > either might result (which may depend on the R platform). ........ > > ----- > > Yes, it is a bit unfortunate that this is platform dependent; if > we wanted to make this entirely consistent (as desired in a > perfect world), I'm almost sure R would become slower because > we'd have to do add some explicit "book keeping" / checking > instead of relying on the underlying C library code. > > Note that for these reasons, often NaN and NA should not be > differentiated, and that's reason why using is.na(*) is > typically sufficient and "best" -- it gives TRUE for both NA and NaN. > > > Martin Maechler > ETH Zurich > > ______________________________________________ > 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. -- Peter Dalgaard, Professor, Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000 Frederiksberg, Denmark Phone: (+45)38153501 Office: A 4.23 Email: pd....@cbs.dk Priv: pda...@gmail.com ______________________________________________ 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.
