There are other functions where R handles a vector argument differently. The first value may be silently used, used with a warning, or trigger an error.
> x <- 1:3 > x:9 [1] 1 2 3 4 5 6 7 8 9 Warning message: In x:9 : numerical expression has 3 elements: only the first used > seq(x, 9) Error in seq.default(x, 9) : 'from' must be of length 1 > rep(1, x) Error in rep(1, x) : invalid 'times' argument ---------------------------------------- David L Carlson Department of Anthropology Texas A&M University College Station, TX 77843-4352 -----Original Message----- From: R-help <r-help-boun...@r-project.org> On Behalf Of Bert Gunter Sent: Wednesday, November 7, 2018 2:49 PM To: Rolf Turner <r.tur...@auckland.ac.nz> Cc: R-help <r-help@r-project.org> Subject: Re: [R] Problem with the matrix() function. I have no opinion on your queries, but whatever is done, it should be properly documented, which appears not to be the case presently afaics. -- Bert On Wed, Nov 7, 2018 at 12:33 PM Rolf Turner <r.tur...@auckland.ac.nz> wrote: > > In the course of writing a bit of somewhat convoluted code I recently > made a silly error that revealed the following phenomenon: > > m <- matrix(1:10,nrow=2,ncol=c(5,4)) > > produces > > > [,1] [,2] [,3] [,4] [,5] > > [1,] 1 3 5 7 9 > > [2,] 2 4 6 8 10 > > That is, the nonsense value of c(5,4) for the "ncol" argument is > accepted, without comment --- the first entry of the given ncol argument > is used. > > It might be argued that this is a reasonable accommodation of the user's > ineptitude. I am of the opinion that an error should be thrown if the > value of ncol is not an integer scalar. > > I have also discerned that if ncol is not an integer, it is replaced by > its floor value. > > Is this a Good Thing? > > What do others think? > > cheers, > > Rolf Turner > > -- > Technical Editor ANZJS > Department of Statistics > University of Auckland > Phone: +64-9-373-7599 ext. 88276 > > ______________________________________________ > 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. > [[alternative HTML version deleted]] ______________________________________________ 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. ______________________________________________ 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.
