title: Format scientific notation in R
body: <p>I have a number which show as </p>
  
  <pre><code>a &lt;- 1.34467773e-5. 
  </code></pre>
  
  <p>I want to format it to </p>
  
  <pre><code>a &lt;- 1.34e-5. 
  </code></pre>
  
  <p>How can I do it?</p>
  
  <p>Thanks.</p>