title: Need example for beta regression predict and plot curve
body: <p>I have just discovered the Beta regression with Betareg package and I would like to see a full simple example using predict() and ploting the fitted regression curve(s) such as in figure 2 page 9 in the betareg vignette document (using the Gasoline yield data from Prater). The author's example (below) only gives the summary of the regression.
  <a href="http://cran.r-project.org/web/packages/betareg/vignettes/betareg.pdf" rel="nofollow">http://cran.r-project.org/web/packages/betareg/vignettes/betareg.pdf</a>.</p>
  
  <pre><code>data("GasolineYield", package = "betareg")
  gy_logit &lt;- betareg(yield ~ batch + temp, data = GasolineYield)
  summary(gy_logit)
  ...
  </code></pre>