R tm package invalid input in 'utf8towcs'

Question

I'm trying to use the tm package in R to perform some text analysis. I tied the following:

require(tm) dataSet <- Corpus(DirSource('tmp/')) dataSet <- tm_map(dataSet, tolower) Error in FUN(X[[6L]], ...) : invalid input 'RT @noXforU Erneut riesiger (Alt-)�lteppich im Golf von Mexiko (#pics vom Freitag) http://bit.ly/bw1hvU http://bit.ly/9R7JCf #oilspill #bp' in 'utf8towcs' 

The problem is some characters are not valid. I'd like to exclude the invalid characters from analysis either from within R or before importing the files for processing.

I tried using iconv to convert all files to utf-8 and exclude anything that can't be converted to that as follows:

find . -type f -exec iconv -t utf-8 "{}" -c -o tmpConverted/"{}" \;  

as pointed out here Batch convert latin-1 files to utf-8 using iconv

But I still get the same error.

I'd appreciate any help.

Answer 1

None of the above answers worked for me. The only way to work around this problem was to remove all non graphical characters (http://stat.ethz.ch/R-manual/R-patched/library/base/html/regex.html).

The code is this simple

usableText=str_replace_all(tweets$text,"[^[:graph:]]", " ")