title: How can I combine numbers into strings in R?
body: <p>I have a data frame with numbers resembling:</p>
  
  <pre><code>df$X1    df$X2
  
  .9     1.442
  </code></pre>
  
  <p>How could I use elements from this data frame to create labels for a confidence intervals that will be nicely formatted string:</p>
  
  <pre><code>(0.90, 1.42)
  </code></pre>
  
  <p>I'm lost somewhere between <code>paste</code>, <code>as.character</code> and <code>c()</code> and nothing seems to work :/</p>