title: Naming columns for data.table in R
body: <p>I have a data.table of the form </p>
  
  <pre><code>   nrow    V1      V2        V3      V4        V5  V6 V7                  V8
   1:    1 chr20     C4b   6382078     C4b   6381944 reg  - Thymus_M_GSM1328751
   2:    2  chr8    Rpl4  68832532    Rpl4  68832743 reg  + Thymus_M_GSM1328751
  </code></pre>
  
  <p>I want to name the columns as ("Chromosome", "Start_Gene","startPosition", "End_gene", "endPosition", "RNAtype", "strand", "replicate"). I tried : </p>
  
  <pre><code>ratData &lt;- ratData[, by= list("Chromosome", "Start_Gene","startPosition", "End_gene", "endPosition", "RNAtype", "strand", "replicate")]
  </code></pre>
  
  <p>But it does not work. I also tried key instead of "by".</p>
  
  <p>How can I do this?</p>