title: Getting the row-index from an OutlierTest table
body: <p>I have run an OutlierTest on a regression model and assigned it to a variable. The <code>class</code> of the table is also <code>outlierTest</code>. I want to extract the row index from this table.</p>
  
  <p>I am not able to convert the table into a <code>data.frame</code> or a <code>matrix</code>.</p>
  
  <pre><code>&gt; library(car)
  
  &gt; b &lt;- outlierTest(fit_train2)
  
  &gt; b
       rstudent unadjusted p-value Bonferonni p
  411  4.976415         1.0296e-06   0.00036243
  372  4.160773         4.0193e-05   0.01414800
  401 -3.987709         8.1658e-05   0.02874400
  373  3.881285         1.2474e-04   0.04391000
  </code></pre>
  
  <p>I basically need something to extract <code>411, 372, 401</code> and <code>373</code> into another vector.</p>
  
  <p>Alternatively, is there any function that provides me with the row-numbers of the influential observations in the data?</p>