The problem is that the basic R functions for reading and writing data from and to files does no work in any reasonable way on Windows. If you are struggling with this you are not alone! There are numerous questions on stackoverflow, blog posts (e.g., this one by Rolf Fredheim, and another by Huidong Tian), and anguished mailing list posts. Thinking of the person-hours wasted on this issue over the years almost brings a tear to my eye.

Let’s try it, using some simplified data from a project I worked on last year. For illustration I’ve created two files containing a mix of English letters, numbers, and Japanese characters. I saved one version with UTF-8 encoding, and another with SHIFT-JIS. On Linux we can read both files easily, provided only that we correctly specify the encoding if the file is not already encoded in UTF-8:

read.csv("japanese_utf8.csv")


  No.         発行日 朝夕刊     面名 ページ
1   1 2015年09月25日   週刊 週刊朝日     22
2   2 2015年09月25日   週刊 週刊朝日     18
3   3 2015年09月21日   朝刊   ３総合      3

read.csv("japanese_shiftjis.csv", fileEncoding = "SHIFT-JIS")


  No.         発行日 朝夕刊     面名 ページ
1   1 2015年09月25日   週刊 週刊朝日     22
2   2 2015年09月25日   週刊 週刊朝日     18
3   3 2015年09月21日   朝刊   ３総合      3

On Windows things are much more difficult. Using read.csv with the default options does not work because read.csv assumes that the encoding of the file matches the Windows locale settings:

read.csv("japanese_utf8.csv")


  No.         ç.ºè.Œæ.. æœ.å..å.Š       é..å.. ペãƒ.ã..
1   1 2015年09月25日    週刊 週刊朝日        22
2   2 2015年09月25日    週刊 週刊朝日        18
3   3 2015年09月21日    朝刊    ３総合         3

Trying to tell R that the file is encoded in UTF-8 not a general solution because read.csv will then try to re-encode from UTF-8 to the native encoding, which may or may not work depending on the contents of the file. On my system trying to read a UTF-8 encoded file containing Japanese characters with the fileEncoding falls flat on its face:

read.csv("japanese_utf8.csv", fileEncoding = "UTF-8")


[1] No. X  
<0 rows> (or 0-length row.names)
Warning messages:
1: In read.table(file = file, header = header, sep = sep, quote = quote,  :
  invalid input found on input connection 'japanese_utf8.csv'
2: In read.table(file = file, header = header, sep = sep, quote = quote,  :
  incomplete final line found by readTableHeader on 'japanese_utf8.csv'

Finally, we might try the encoding argument rather than fileEncoding. This simply marks the strings with the specified encoding:

read.csv("japanese_utf8.csv", encoding = "UTF-8")


read.csv("japanese_utf8.csv", encoding = "UTF-8")
  No.        X.U.767A..U.884C..U.65E5. X.U.671D..U.5915..U.520A.                X.U.9762..U.540D. X.U.30DA..U.30FC..U.30B8.
1   1 2015<U+5E74>09<U+6708>25<U+65E5>          <U+9031><U+520A> <U+9031><U+520A><U+671D><U+65E5>                        22
2   2 2015<U+5E74>09<U+6708>25<U+65E5>          <U+9031><U+520A> <U+9031><U+520A><U+671D><U+65E5>                        18
3   3 2015<U+5E74>09<U+6708>21<U+65E5>          <U+671D><U+520A>                3<U+7DCF><U+5408>                         3

This kind of works, though you wouldn’t know it from the output. As mentioned above, there is a bug in the print.data.frame function that prevents UTF-8 encoded text from displaying correctly. We can use another print method to see that the column values have been read in correctly:

print.listof(read.csv("japanese_utf8.csv", encoding = "UTF-8"))


No. :
[1] 1 2 3

X.U.767A..U.884C..U.65E5. :
[1] "2015年09月25日" "2015年09月25日" "2015年09月21日"

X.U.671D..U.5915..U.520A. :
[1] "週刊" "週刊" "朝刊"

X.U.9762..U.540D. :
[1] "週刊朝日" "週刊朝日" "３総合"  

X.U.30DA..U.30FC..U.30B8. :
[1] 22 18  3

Unfortunately there are two problems with this: first, the names of the columns have not been correctly encoded, and second, this will only work if your input data is in UTF-8 in the first place. Trying to apply this strategy to our SHIFT-JIS encoded file will not work at all because we cannot mark strings with arbitrary encoding, only with UTF-8¹. Trying to mark the string as SHIFT-JIS will silently fail:

print.listof(read.csv("japanese_shiftjis.csv", encoding = "SHIFT-JIS"))


No. :
[1] 1 2 3

X...s.ú :
[1] "2015”N09ŒŽ25“ú" "2015”N09ŒŽ25“ú" "2015”N09ŒŽ21“ú"

X....Š. :
[1] "TŠ§" "TŠ§" "’©Š§"

X.Ê.. :
[1] "TŠ§’©“ú" "TŠ§’©“ú" "‚R‘‡"  

ƒy..ƒW :
[1] 22 18  3

Ouch! Why is this so hard? Can we make it suck less?

Basically R gives you two ways of handling character encoding. You can use the default encoding of your OS, or you can use UTF-8¹. On OS X and Linux these options are often the same, since the default OS encoding is usually UTF-8; this is a great advantage because just about everything can be represented in UTF-8. On Windows there is no such luck. On my Windows 7 machine the default is “Windows code page 1252”; many characters (such as Japanese) cannot be represented in code page 1252. If I want to work with Japanese text in R on Windows I have two options; change my locale to Japanese, or I can convert strings to UTF-8 and mark them as such.

In some ways just changing your locale to one that can accommodate the data you are working with is the simplest approach. Again, on Mac and Linux the locale usually specifies UTF-8 encoding, so no changes are needed; things should just work as you would expect them to. On windows we can change the locale to match the data we are working with using the Sys.setlocale function. This sometimes works well; for example, we can read our UTF-8 and SHIFT-JIS encoded data on Windows as follows:

setlocale("LC_ALL", "English_United States.932")
read.csv("japanese_shiftjis.csv")
read.csv("japanese_utf8.csv", fileEncoding = "UTF-8")


[1] "LC_COLLATE=English_United States.932;LC_CTYPE=English_United States.932;LC_MONETARY=English_United States.932;LC_NUMERIC=C;LC_TIME=English_United States.932"

  No.         発行日 朝夕刊     面名 ページ
1   1 2015年09月25日   週刊 週刊朝日     22
2   2 2015年09月25日   週刊 週刊朝日     18
3   3 2015年09月21日   朝刊   ３総合      3

  No.         発行日 朝夕刊     面名 ページ
1   1 2015年09月25日   週刊 週刊朝日     22
2   2 2015年09月25日   週刊 週刊朝日     18
3   3 2015年09月21日   朝刊   ３総合      3

This works fine until we want to read some other kind of text in the same R session, and then we are right back to the same old problem. Another issue with this method is that it does not work in Rstudio unless the locale is set on startup; you cannot change the locale of a running session in Rstudio².

Because the Sys.setlocale method only works for a subset of languages in any given session, our best bet is to read store everything in UTF-8 (and make sure it is marked as such). It is not convenient to do this using the read.table family of functions in R, but it is possible with some care:

x <- read.csv("japanese_shiftjis.csv", 
	      encoding = "UTF-8", 
	      check.names = FALSE # otherwise R will mangle the names
	      )
charcols <- !sapply(x, is.numeric)
x[charcols] <- lapply(x[charcols], iconv, from = "SHIFT-JIS", to = "UTF-8")
names(x) <- iconv(names(x), from = "SHIFT-JIS", to = "UTF-8")
print.listof(x)


No. :
[1] 1 2 3

発行日 :
[1] "2015年09月25日" "2015年09月25日" "2015年09月21日"

朝夕刊 :
[1] "週刊" "週刊" "朝刊"

面名 :
[1] "週刊朝日" "週刊朝日" "３総合"  

ページ :
[1] 22 18  3

OK it works, but honestly that too much work for something as simple as reading a .csv file into R. As suggested at the beginning of this post, a better strategy is to use the readr package because it will do the conversion to UTF-8 for you:

print.listof(read_csv("arabic_utf-8.csv"), locale = locale(encoding = "UTF-8"))
print.listof(read_csv("japanese_utf8.csv"), locale = locale(encoding = "UTF-8"))
print.listof(read_csv("japanese_shiftjis.csv"), locale = locale(encoding = "SHIFT-JIS"))


X5 :
[1] "1895-01-02" "1895-01-07" "1895-01-16"
X8 :
[1] "اصلى" "اصلى" "اصلى"
X12 :
[1] "وقائع" "وقائع" "وقائع"

No. :
[1] "00001" "00002" "00003"
発行日 :
[1] "2015年09月25日" "2015年09月25日" "2015年09月21日"
朝夕刊 :
[1] "週刊" "週刊" "朝刊"
面名 :
[1] "週刊朝日" "週刊朝日" "３総合"  
ページ :
[1] "022" "018" "003"


No. :
[1] "00001" "00002" "00003"
発行日 :
[1] "2015年09月25日" "2015年09月25日" "2015年09月21日"
朝夕刊 :
[1] "週刊" "週刊" "朝刊"
面名 :
[1] "週刊朝日" "週刊朝日" "３総合"  
ページ :
[1] "022" "018" "003"

Here are the example data files and code and needed to run the examples in this post.