[R] Non-ACSII characters in R on Windows

[Milan Bouchet-Valat]

Le lundi 16 septembre 2013 à 13:39 -0400, Duncan Murdoch a écrit :
> On 16/09/2013 12:04 PM, Maxim Linchits wrote:
> > Here is that old post:
> > http://r.789695.n4.nabble.com/read-csv-and-FileEncoding-in-Windows-version-of-R-2-13-0-td3567177.html
> 
> In that post, you'll see I asked for a sample file.  I never received 
> any reply; presumably some spam filter didn't like what Alexander sent 
> me, and Nabble doesn't archive any attachment.
> 
> Similarly, the Stackoverflow thread contains no sample data.
> 
> Could someone who is having this problem please put a small sample 
> online for download?  As I told Alexander last time, my experiments with 
> files I constructed myself showed no errors.
Yes, this was my first reaction, and then I saw the link to a second
thread on StackOverflow with such an example. This is the one I took in
my previous posts in this thread. If you want to get the file directly
instead of pasting the contents it by hand, here is a version that
should be enough:
http://nalimilan.perso.neuf.fr/transfert/utf8.csv


Regards

> Duncan Murdoch
> 
> >
> > A taste: "Again, the issue is that opening this UTF-8 encoded file
> > under R 2.13.0 yields an error, but opening it under R 2.12.2 works
> > without any issues. (...)"
> >
> > On Mon, Sep 16, 2013 at 6:38 PM, Milan Bouchet-Valat <nalimilan at club.fr> wrote:
> > > Le lundi 16 septembre 2013 à 10:40 +0200, Milan Bouchet-Valat a écrit :
> > >> Le vendredi 13 septembre 2013 à 23:38 +0400, Maxim Linchits a écrit :
> > >> > This is a condensed version of the same question on stackexchange here:
> > >> > http://stackoverflow.com/questions/18789330/r-on-windows-character-encoding-hell
> > >> > If you've already stumbled upon it feel free to ignore.
> > >> >
> > >> > My problem is that R on US Windows does not read *any* text file that
> > >> > contains *any* foreign characters. It simply reads the first consecutive n
> > >> > ASCII characters and then throws a warning once it reached a foreign
> > >> > character:
> > >> >
> > >> > > test <- read.table("test.txt", sep=";", dec=",", quote="",
> > >> > fileEncoding="UTF-8")
> > >> > Warning messages:
> > >> > 1: In read.table("test.txt", sep = ";", dec = ",", quote = "", fileEncoding
> > >> > = "UTF-8") :
> > >> >   invalid input found on input connection 'test.txt'
> > >> > 2: In read.table("test.txt", sep = ";", dec = ",", quote = "", fileEncoding
> > >> > = "UTF-8") :
> > >> >   incomplete final line found by readTableHeader on 'test.txt'
> > >> > > print(test)
> > >> >        V1
> > >> > 1 english
> > >> >
> > >> > > Sys.getlocale()
> > >> >    [1] "LC_COLLATE=English_United States.1252;LC_CTYPE=English_United
> > >> > States.1252;
> > >> >      LC_MONETARY=English_United
> > >> > States.1252;LC_NUMERIC=C;LC_TIME=English_United States.1252"
> > >> >
> > >> >
> > >> > It is important to note that that R on linux will read UTF-8 as well as
> > >> > exotic character sets without a problem. I've tried it with the exact same
> > >> > files (one was UTF-8 and another was OEM866 Cyrillic).
> > >> >
> > >> > If I do not include the fileEncoding parameter, read.table will read the
> > >> > whole CSV file. But naturally it will read it wrong because it does not
> > >> > know the encoding. So whenever I try to specify the fileEncoding, R will
> > >> > throw the warnings and stop once it reaches a foreign character. It's the
> > >> > same story with all international character encodings.
> > >> > Other users on stackexchange have reported exactly the same issue.
> > >> >
> > >> >
> > >> > Is anyone here who is on a US version of Windows able to import files with
> > >> > foreign characters? Please let me know.
> > >> A reproducible example would have helped, as requested by the posting
> > >> guide.
> > >>
> > >> Though I am also experiencing the same problem after saving the data
> > >> below to a CSV file encoded in UTF-8 (you can do this using even the
> > >> Notepad):
> > >> "Ա","Բ"
> > >> 1,10
> > >> 2,20
> > >>
> > >> This is on a Windows 7 box using French locale, but same codepage 1252
> > >> as yours. What is interesting is that reading the file using
> > >> readLines(file("myFile.csv", encoding="UTF-8"))
> > >> gives no invalid characters. So there must be a bug in read.table().
> > >>
> > >>
> > >> But I must note I do not experience issues with French accentuated
> > >> characters like "é" ("\Ue9"). On the contrary, reading Armenian
> > >> characters like "Ա" ("\U531") gives weird results: the character appears
> > >> as <U+0531> instead of Ա.
> > >>
> > >> Self-contained example, writing the file and reading it back from R:
> > >> tmpfile <- tempfile()
> > >> writeLines("\U531", file(tmpfile, "w", encoding="UTF-8"))
> > >> readLines(file(tmpfile, encoding="UTF-8"))
> > >> # "<U+0531>"
> > >>
> > >> The same phenomenon happens when creating a data frame from this
> > >> character (as noted on StackExchange):
> > >> data.frame("\U531")
> > >>
> > >> So my conclusion is that maybe Windows does not really support Unicode
> > >> characters that are not "relevant" for your current locale. And that may
> > >> have created bugs in the way R handles them in read.table(). R
> > >> developers can probably tell us more about it.
> > > After some more investigation, one part of the problem can be traced
> > > back to scan() (with myFile.csv filled as described above):
> > > scan("myFile.csv", encoding="UTF-8", sep=",", nlines=1)
> > > # Read 2 items
> > > # [1] "Ա" "Բ"
> > >
> > > Equivalent, but nonsensical to me:
> > > scan("myFile.csv", fileEncoding="CP1252", encoding="UTF-8", sep=",", nlines=1)
> > > # Read 2 items
> > > # [1] "Ա" "Բ"
> > >
> > > scan("myFile.csv", fileEncoding="UTF-8", sep=",", nlines=1)
> > > # Read 0 items
> > > # character(0)
> > > # Warning message:
> > > # In scan(file, what, nmax, sep, dex, quote, skip, nlines, na.strings,  :
> > > #  invalid input found on input connection 'myFile.csv'
> > >
> > >
> > > So there seem to be one part of the issue in scan(), which for some
> > > reason does not work when passed fileEncoding="UTF-8"; and another part
> > > in read.table(), which transforms "Ա" ("\U531") into "X.U.0531.",
> > > probably via make.names(), since:
> > > make.names("\U531")
> > > # "X.U.0531."
> > >
> > >
> > > Does this make sense to R-core members?
> > >
> > >
> > > Regards
> >
> > ______________________________________________
> > 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.