title: R - write to file without colum 0 (write.csv or write.table)
body: <p>Suppose I have got the following data frame, named <code>highly expressed</code> </p>
  
  <pre><code>|    |New IDs         | Mean amast| Mean promast|Old IDs        |
  |:---|:---------------|----------:|------------:|:--------------|
  |44  |LdBPK_010009200 |   37.16175|     33.72800|LdBPK_010440.1 |
  |46  |LdBPK_010009300 |   35.67275|     32.05529|LdBPK_010440.1 |
  |83  |LdBPK_010012800 |    6.84300|     16.04800|LdBPK_010790.1 |
  |84  |LdBPK_010012900 |    6.92775|     15.62371|LdBPK_010790.1 |
  |93  |LdBPK_020005100 |    5.89950|     27.03371|LdBPK_210020.1 |
  |300 |LdBPK_030014900 |    7.59575|     12.38143|LdBPK_030960.1 |
  </code></pre>
  
  <p>I now want to get a list containing exclusively the strings under "Old IDs" (i.e. the whole fourth column) for further data manipulation. When I write the following command:</p>
  
  <pre><code>write.table(highly_expressed$`Old IDs`, file = "test", quote = F, sep = "\t")
  </code></pre>
  
  <p>my output file contains two columns (an not only one, as I was expecting), as shown below:</p>
  
  <pre><code>|  X|x              |
  |--:|:--------------|
  |  1|LdBPK_010440.1 |
  |  2|LdBPK_010440.1 |
  |  3|LdBPK_010790.1 |
  |  4|LdBPK_010790.1 |
  |  5|LdBPK_210020.1 |
  |  6|LdBPK_030960.1 |
  </code></pre>
  
  <p>Does anyone know a way to write to file without the column 0 (the indices 1, 2, 3, 4 etc)? Maybe using another function other than write.csv?</p>