title: Changing values in a range of columns using R
body: <p>I'm trying to change certain column's values using something like this:</p>
  
  <p>This works fine:</p>
  
  <pre><code>DF[,(6:12)][DF[,(6:12)]!=""]&lt;- 13
  </code></pre>
  
  <p>This throws an error:</p>
  
  <pre><code>DF[,(6:12,23:25)][DF[,(6:12:23:25)]!=""]&lt;- 13
  
  Error: unexpected ','
  </code></pre>
  
  <p>Why?  How can I specify multiple ranges here?</p>