title: Name columns within aggregate in R
body: <p>I know I can *re*name columns after I aggregate the data:</p>
  
  <pre><code>blubb &lt;- aggregate(dat$two ~ dat$one, ...)
  colnames(blubb) &lt;- c("One", "Two")
  </code></pre>
  
  <p>Nothing wrong with that. But is there a way to aggregate and name the columns in one go? Sort of like:</p>
  
  <pre><code>blubb &lt;- aggregate( ... , cols = c("One", "Two"))
  </code></pre>
  
  <p>It would be escpecially nice (and typo-proof) to somehow catch the original column names and do like:</p>
  
  <pre><code>blubb &lt;- aggregate( ... , cols = c(name_of_dat$one, name_of_dat$two."_Mean"))
  </code></pre>