title: Need help for using davies.test in segmented package
body: <p>Sorry to ask such a stupid question, but I'm really confused about it!
  I have a piecewise linear regression with one breakpoint and now I want to test for significant differences of slopes with <code>davies.test</code> in package <code>segmented</code>:</p>
  
  <pre><code>lin.mod &lt;- lm(y~x)
  segmented.mod &lt;- segmented(lin.mod, seg.Z=~x)
  </code></pre>
  
  <p>Now which one is correct for davies test?</p>
  
  <pre><code>davies.test(lin.mod, seg.Z=~x) 
  </code></pre>
  
  <p>or </p>
  
  <pre><code>davies.test(segmented.mod, seg.Z=~x)
  </code></pre>