[r] File path issues in R using Windows ("Hex digits in character string" error)

I run R on Windows, and have a csv file on the Desktop. I load it as follows,

x<-read.csv("C:\Users\surfcat\Desktop\2006_dissimilarity.csv",header=TRUE)

but the R gives the following error message

Error: '\U' used without hex digits in character string starting "C:\U"

So what's the correct way to load this file. I am using Vista

Replace back slashes \ with forward slashes / when running windows machine

I know this is really old, but if you are copying and pasting anyway, you can just use:

read.csv(readClipboard())

readClipboard() escapes the back-slashes for you. Just remember to make sure the ".csv" is included in your copy, perhaps with this:

read.csv(paste0(readClipboard(),'.csv'))

And if you really want to minimize your typing you can use some functions:

setWD <- function(){
  setwd(readClipboard())
}


readCSV <- function(){
  return(readr::read_csv(paste0(readClipboard(),'.csv')))
} 

#copy directory path
setWD()

#copy file name
df <- readCSV()

Please do not mark this response as correct as smitec has already answered correctly. I'm including a convenience function I keep in my .First library that makes converting a windows path to the format that works in R (the methods described by Sacha Epskamp). Simply copy the path to your clipboard (ctrl + c) and then run the function as pathPrep(). No need for an argument. The path is printed to your console correctly and written to your clipboard for easy pasting to a script. Hope this is helpful.

pathPrep <- function(path = "clipboard") {
    y <- if (path == "clipboard") {
        readClipboard()
    } else {
        cat("Please enter the path:\n\n")
        readline()
    }
    x <- chartr("\\", "/", y)
    writeClipboard(x)
    return(x)
}

I think that R is reading the '\' in the string as an escape character. For example \n creates a new line within a string, \t creates a new tab within the string.

'\' will work because R will recognize this as a normal backslash.

readClipboard() works directly too. Copy the path into your clipboard

C:\Users\surfcat\Desktop\2006_dissimilarity.csv

Then

readClipboard()

appears as

[1] "C:\\Users\\surfcat\\Desktop\\2006_dissimilarity.csv"

Replacing backslash with forward slash worked for me on Windows.

My Solution is to define an RStudio snippet as follows:

snippet pp
    "`r gsub("\\\\", "\\\\\\\\\\\\\\\\", readClipboard())`"

This snippet converts backslashes \ into double backslashes \\. The following version will work if you prefer to convert backslahes to forward slashes /.

snippet pp
    "`r gsub("\\\\", "/", readClipboard())`"

Once your preferred snippet is defined, paste a path from the clipboard by typing p-p-TAB-ENTER (that is pp and then the tab key and then enter) and the path will be magically inserted with R friendly delimiters.

The best way to deal with this in case of txt file which contains data for text mining (speech, newsletter, etc.) is to replace "\" with "/".

Example:

file<-Corpus(DirSource("C:/Users/PRATEEK/Desktop/training tool/Text Analytics/text_file_main"))

Solution

Try this: x <- read.csv("C:/Users/surfcat/Desktop/2006_dissimilarity.csv", header=TRUE)

Explanation

R is not able to understand normal windows paths correctly because the "\" has special meaning - it is used as escape character to give following characters special meaning (\n for newline, \t for tab, \r for carriage return, ..., have a look here ).

Because R does not know the sequence \U it complains. Just replace the "\" with "/" or use an additional "\" to escape the "\" from its special meaning and everything works smooth.

Alternative

On windows, I think the best thing to do to improve your workflow with windows specific paths in R is to use e.g. AutoHotkey which allows for custom hotkeys:

• define a Hotkey, e.g. Cntr-Shift-V
• assigns it an procedure that replaces backslashes within your Clipboard with slaches ...
• when ever you want to copy paste a path into R you can use Cntr-Shift-V instead of Cntr-V
• Et-voila

AutoHotkey Code Snippet (link to homepage)

^+v::
StringReplace, clipboard, clipboard, \, /, All 
SendInput, %clipboard% 

A simple way is to use python. in python terminal type

r"C:\Users\surfcat\Desktop\2006_dissimilarity.csv" and you'll get back 'C:\Users\surfcat\Desktop\2006_dissimilarity.csv'