title: Cluster Standard Errors of an RQPD object
body: <p>How does one cluster the standard errors of an rqpd object? The function <code>summary.rqpd</code> does not seem to allow a &quot;cluster&quot; option.</p>
  <p>Minimum working example:</p>
  <pre><code># install.packages(&quot;rqpd&quot;, repos=&quot;http://R-Forge.R-project.org&quot;)
  library(rqpd)
  x &lt;- 1:50 
  y &lt;- c(x[1:48] + rnorm(48, 0, 5), rnorm(2, 150, 5))
  cluster &lt;- rep(letters[1:5], 10)
  QR &lt;- rqpd(y ~ x|cluster, panel(lambda=5))
  
  #The function does not have a &quot;cluster&quot; option
  summary.rqpd(QR, se='boot')
  </code></pre>