>>>>> "TP" == Tony Plate <tpl...@acm.org> >>>>> on Fri, 16 Jan 2009 13:10:04 -0700 writes:
TP> Martin Maechler wrote: >>>>>>> "PatB" == Patrick Burns <pbu...@pburns.seanet.com> >>>>>>> on Tue, 13 Jan 2009 17:00:40 +0000 writes: >>>>>>> >> PatB> Henrik Bengtsson wrote: >> >> Hi. >> >> >> >> On Mon, Jan 12, 2009 at 11:58 PM, Prof Brian Ripley >> >> <rip...@stats.ox.ac.uk> wrote: >> >> >> >>> What you have is a one-dimensional array: they crop up >> >>> in R most often from table() in my experience. >> >>> >> >>> >> >>>> f <- table(rpois(100, 4)) str(f) >> >>>> >> >>> 'table' int [, 1:10] 2 6 18 21 13 16 13 4 3 4 - attr(*, >> >>> "dimnames")=List of 1 ..$ : chr [1:10] "0" "1" "2" "3" >> >>> ... >> >>> >> >>> and yes, f is an atmoic vector and yes, str()'s notation >> >>> is confusing here but if it did [1:10] you would not >> >>> know it was an array. I recall discussing this with >> >>> Martin Maechler (str's author) last century, and I've >> >>> just checked that R 2.0.0 did the same. >> >>> >> >>> The place in which one-dimensional arrays differ from >> >>> normal vectors is how names are handled: notice that my >> >>> example has dimnames not names, and ?names says >> >>> >> >>> For a one-dimensional array the 'names' attribute really >> >>> is 'dimnames[[1]]'. >> >>> >> >> >> >> Thanks for this explanation. One could then argue that >> >> [1:10,] is somewhat better than [,1:10], but that is just polish. >> >> yes. And honestly I don't remember anymore why I chose the >> "[,1:n]" notation. It definitely was there already before R >> came into existence, as S also has had one-dimensional arrays, >> and I programmed the first version of str() in 1990. >> PatB> Perhaps it could be: >> PatB> [1:10(,)] >> PatB> That is weird enough that it should not lead people to PatB> believe that it is a matrix. But might prompt them a PatB> bit in that direction. >> >> Well, str() was always aimed a bit at experienced S (and R) >> users, and I had always aimed somewhat to keep it's output >> "compact". I'm quite astonished that the OP didn't know about >> 1D arrays in spite of the many years he's been using R. >> Would a wierd solution like the above have helped? >> >> At the moment, I'd tend to keep it "as is" if only just for >> historical reminescence, but I can be convinced to change the >> current "tendency" ... >> >> Martin Maechler, ETH Zurich >> TP> What about just including "(1d-array)", something like this >> str(f) TP> 'table' int [1:10](1d array) 5 5 9 23 26 16 9 4 2 1 TP> - attr(*, "dimnames")=List of 1 TP> ..$ : chr [1:10] "0" "1" "2" "3" ... >> TP> only 9 extra characters for a rare case, and much, much less cryptic? well,.. the next text request is to use "character" instead of "chr", only 6 extra characters .... -> no way: str() has its very concise "style" and should keep that. Martin TP> -- Tony Plate >> >> PatB> Patrick Burns patr...@burns-stat.com +44 (0)20 8525 PatB> 0696 http://www.burns-stat.com (home of "The R PatB> Inferno" and "A Guide for the Unwilling S User") >> >> /Henrik >> >> >> >> >> >>> I think these days we have enough internal glue in place >> >>> that an end user would not notice the difference (but >> >>> those working at C level with R objects may need to >> >>> know). >> >>> >> >>> On Mon, 12 Jan 2009, Henrik Bengtsson wrote: >> >>> >> >>> >> >>>> Ran into the follow intermediate case in an external >> >>>> package (w/ recent R v2.8.1 patched and R v2.9.0 >> >>>> devel): >> >>>> >> >>>> >> >>>>> x <- 1:2 dim(x) <- 2 dim(x) >> >>>>> >> >>>> [1] 2 >> >>>> >> >>>>> x >> >>>>> >> >>>> [1] 1 2 >> >>>> >> >>>>> str(x) >> >>>>> >> >>>> int [, 1:2] 1 2 >> >>>> >> >>>>> nrow(x) >> >>>>> >> >>>> [1] 2 >> >>>> >> >>>>> ncol(x) >> >>>>> >> >>>> [1] NA >> >>>> >> >>>>> is.vector(x) >> >>>>> >> >>>> [1] FALSE >> >>>> >> >>>>> is.matrix(x) >> >>>>> >> >>>> [1] FALSE >> >>>> >> >>>>> is.array(x) >> >>>>> >> >>>> [1] TRUE >> >>>> >> >>>>> x[1] >> >>>>> >> >>>> [1] 1 >> >>>> >> >>>>> x[,1] >> >>>>> >> >>>> Error in x[, 1] : incorrect number of dimensions >> >>>> >> >>>>> x[1,] >> >>>>> >> >>>> Error in x[1, ] : incorrect number of dimensions >> >>>> >> >>>> Is str() treating single-dimension arrays incorrectly? >> >>>> >> >>>> What does it mean to have a single dimension this way? >> >>>> Should it equal a vector? I am aware of "is.vector >> >>>> returns FALSE if x has any attributes except names". >> >>>> >> >>>> /Henrik >> >>>> >> >>>> ______________________________________________ >> >>>> R-devel@r-project.org mailing list >> >>>> https://stat.ethz.ch/mailman/listinfo/r-devel >> >>>> >> >>>> >> >>> -- >> >>>> Brian D. Ripley, rip...@stats.ox.ac.uk 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 >> >>> >> >>> >> >> >> >>> ______________________________________________ >>> >> >> R-devel@r-project.org mailing list >> >> https://stat.ethz.ch/mailman/listinfo/r-devel >> >> >> >> >> >> >> >> ______________________________________________ PatB> R-devel@r-project.org mailing list PatB> https://stat.ethz.ch/mailman/listinfo/r-devel >> >> ______________________________________________ >> R-devel@r-project.org mailing list >> https://stat.ethz.ch/mailman/listinfo/r-devel >> >> TP> ______________________________________________ TP> R-devel@r-project.org mailing list TP> https://stat.ethz.ch/mailman/listinfo/r-devel ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel