title: Unicode characters in R data frame
body: <p>I have a data frame that containts polish diacritic signs however in my data frame they are presented as e.g. <code>ZESP\xc3\x93\xc5\x81 SZK\xc3\x93\xc5\x81</code> which should be <code>ZESPÓŁ SZKÓŁ</code>. I was trying to make a replace for all of those characeters: 
  e.g. </p>
  
  <pre><code>x &lt;- "SP\\xc3\\x93\\xc5\\x81KA"
  x1 &lt;- data.frame(x)
  
  data &lt;- data.frame(lapply(x1, function(df3) {
                      gsub("SP\\xc3\\x93\\xc5\\x81KA", "SPÓŁKA", df3)
                }))
  </code></pre>
  
  <p>However such a replace does not work. How to deal with those type of data frames? How to force it to display correct diacritic signs?</p>
  
  <p><strong>I have added a fully reproducible example. Any ideas? Some solutions?</strong></p>