title: Change column names of data.frame based on column number and text
body: <p>In the data.frame <code>run</code></p>
  
  <pre><code>run &lt;- data.frame(1:4,2:5,3:6)
    X1.4 X2.5 X3.6
  1    1    2    3
  2    2    3    4
  3    3    4    5
  4    4    5    6
  </code></pre>
  
  <p>I want to change the column names to</p>
  
  <pre><code>&gt; colnames(run) &lt;- c("runner1", "runner2", "runner3")
  </code></pre>
  
  <p>Is there a way to do this in R code (imagine I have hundreds of columns) by combining a similar text <code>runner</code> with a serial number <code>1, 2, 3...</code></p>
  
  <p>I started with
  <code>c(rbind(rep(c("runner"), each=3), c(1:3)))</code> which does not work and is probably way too complicated.</p>
  
  <p>I suppose there is a easy solution?</p>