Hi
I came across this strange bug the other day, I'm not sure how to solve it
and I wonder if anyone can even replicate it.
Using OS Ubuntu 7.10
Step 1) Make an R package using the package.skeleton() command with
only these two functions:
error <- function(){
cmd <- paste(" -a ",1," -a ",1," -a ",1,
" -a ",1," -a ",1," -a ",1,
" -a ",1," -a ",1," -a ",1,
" -a ",1," -a ",1," -a ",1,
" ?a ",1,sep="")
cat(cmd,"\n")
}
noerror <- function(){
cmd <- paste(" -a ",1," -a ",1," -a ",1,
" -a ",1," -a ",1," -a ",1,
" -a ",1," -a ",1," -a ",1,
" -a ",1," -a ",1," -a
",1,sep="")
cat(cmd,"\n")
}
Step 2) Start R again. Load the package with library() and run the commands:
error()
noerror()
I get the following output:> > library(errors)
> error()
-a 1 -a 1 -a 1 -a 1 -a 1 -a 1 -a 1 -a 1 -a 1 -a 1 -a 1 -a 1
<e2><80><93>a 1> noerror()
-a 1 -a 1 -a 1 -a 1 -a 1 -a 1 -a 1 -a 1 -a 1 -a 1 -a 1 -a
1>
Now why does that "<e2><80><93>" replace one of the
"-" in the first command?
Any ideas?
Cheers
Tom
--
Thomas Allen
Department of Biochemistry
University of Otago
email1: hedbag at gmail.com
email2: allth025 at student.otago.ac.nz
Work: (+64)3 479 5123
Mobile: 027 321 4269
G'day Thomas, On Tue, 4 Mar 2008 14:40:35 +1300 "Thomas Allen" <hedbag at gmail.com> wrote:> I came across this strange bug the other day, I'm not sure how to > solve it and I wonder if anyone can even replicate it.> Step 1) Make an R package using the package.skeleton() command with > only these two functions: > > error <- function(){ > cmd <- paste(" -a ",1," -a ",1," -a ",1, > " -a ",1," -a ",1," -a ",1, > " -a ",1," -a ",1," -a ",1, > " -a ",1," -a ",1," -a ",1, > " ?a ",1,sep="") > cat(cmd,"\n") > }> Now why does that "<e2><80><93>" replace one of the "-" in the first > command?With my mailtool, the "-" before the last a looks a bit longer than the others; it definitely seems to be a different tool. Also, if I cut and paste this function into an emacs buffer on my Kubuntu machine, I see: error <- function(){ cmd <- paste(" -a ",1," -a ",1," -a ",1, " -a ",1," -a ",1," -a ",1, " -a ",1," -a ",1," -a ",1, " -a ",1," -a ",1," -a ",1, " \u2013a ",1,sep="") cat(cmd,"\n") } So somehow you must have entered not a "-" but some other symbol before that last a. And I guess what you see is a result of the locale and the character encoding that you are working in. But others would know more about this than I and can probably explain better what is going on. Cheers, Berwin =========================== Full address ============================Berwin A Turlach Tel.: +65 6516 4416 (secr) Dept of Statistics and Applied Probability +65 6516 6650 (self) Faculty of Science FAX : +65 6872 3919 National University of Singapore 6 Science Drive 2, Blk S16, Level 7 e-mail: statba at nus.edu.sg Singapore 117546 http://www.stat.nus.edu.sg/~statba
On Tue, 4 Mar 2008, Thomas Allen wrote:> Hi > > I came across this strange bug the other day, I'm not sure how to solve it > and I wonder if anyone can even replicate it. > > Using OS Ubuntu 7.10 > > Step 1) Make an R package using the package.skeleton() command with > only these two functions: > > error <- function(){ > cmd <- paste(" -a ",1," -a ",1," -a ",1, > " -a ",1," -a ",1," -a ",1, > " -a ",1," -a ",1," -a ",1, > " -a ",1," -a ",1," -a ",1, > " ?a ",1,sep="") > cat(cmd,"\n") > } > noerror <- function(){ > cmd <- paste(" -a ",1," -a ",1," -a ",1, > " -a ",1," -a ",1," -a ",1, > " -a ",1," -a ",1," -a ",1, > " -a ",1," -a ",1," -a ",1,sep="") > cat(cmd,"\n") > } > > Step 2) Start R again. Load the package with library() and run the commands: > error() > noerror() > > I get the following output: >>> library(errors) >> error() > -a 1 -a 1 -a 1 -a 1 -a 1 -a 1 -a 1 -a 1 -a 1 -a 1 -a 1 -a 1 <e2><80><93>a 1 >> noerror() > -a 1 -a 1 -a 1 -a 1 -a 1 -a 1 -a 1 -a 1 -a 1 -a 1 -a 1 -a 1 >> > > Now why does that "<e2><80><93>" replace one of the "-" in the first command?Because you put it there! I believe that at the first step you were running R in a UTF-8 locale, and at the second in (probably) an 8-bit locale. I can reproduce this by changing from en_GB.utf8 to en_GB on F8, for example. <e2><80><93> is UTF-8 for the Unicode point U+2013, the en dash. I don't know how you managed to enter that in UTF-8 (I would have not have expected it to be accidentally possible from the keyboard), but the solution is to use hyphen where you intend hyphen. (Unicode calls this 'HYPHEN-MINUS' to indicate its dual role -- it also has U+2212 for minus.)> > Any ideas? > > Cheers > > Tom > > -- > Thomas Allen > Department of Biochemistry > University of Otago > email1: hedbag at gmail.com > email2: allth025 at student.otago.ac.nz > Work: (+64)3 479 5123 > Mobile: 027 321 4269 > > ______________________________________________ > R-help at 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. >-- Brian D. Ripley, ripley at 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