title: In R a error occurs in write.csv after strsplit
body: <p>I have a dataframe which once I split the terms in col (X) the DF becomes un-writable. I am prompted with this error</p>
  
  <pre><code>Error in .External2(C_writetable, x, file, nrow(x), p, rnames, sep,
  eol,  :    unimplemented type 'list' in 'EncodeElement'
  </code></pre>
  
  <p>My originally DF (DF1), which is writable, looks like this</p>
  
  <pre><code>        SentrixPosition     Chormosomal.position
  504   4578150569_R01C01   chr2:41238644-41245501
  504.1 4578150569_R01C01 chr1:247849473-247925390
  504.2 4578150569_R01C01   chr2:17221404-17232378
  504.3 4578150569_R01C01     chr5:7177740-7202086
  504.4 4578150569_R01C01   chr8:95721435-95744466
  </code></pre>
  
  <p>after string splitting the column Chormosomal.position in 3 further columns. The file is no longer writable and the error previously mentioned arises. The new DF look like:  </p>
  
  <pre><code>           SentrixPosition     Chormosomal.position  chr  startPos    endPos
  504   4578150569_R01C01   chr2:41238644-41245501 chr2  41238644  41245501
  504.1 4578150569_R01C01 chr1:247849473-247925390 chr1 247849473 247925390
  504.2 4578150569_R01C01   chr2:17221404-17232378 chr2  17221404  17232378
  504.3 4578150569_R01C01     chr5:7177740-7202086 chr5   7177740   7202086
  504.4 4578150569_R01C01   chr8:95721435-95744466 chr8  95721435  95744466
  </code></pre>