title: How to create conditional error bars in ggplot
body: <p>I am trying to display conditional error bars, for example, when I ran this I see the error bars for all values. </p>
  
  <pre><code>d &lt;- qplot(cyl, mpg, data=mtcars)
  d + stat_summary(fun.ymin=min,fun.ymax=max,geom="errorbar")
  </code></pre>
  
  <p>I would like to display the above error bars only if N > than a specified value. Is there a way of doing this? </p>