title: Convert several columns from integer to numeric in R data.frame
body: <p>I would like to convert columns from 2 to 13 (the last one) from integer to numeric.</p>
  
  <p>For one column, I use the following code:</p>
  
  <pre><code>dades$V3 &lt;- as.numeric(dades$V3)
  </code></pre>
  
  <p>I want to convert columns from 2 to 13 with the same command. I create this vector:</p>
  
  <pre><code>dades&lt;-2:13
  </code></pre>
  
  <p>Then, how do I use <code>lapply</code>?</p>