title: How to control ylim for a faceted plot with different scales in ggplot2?
body: <p>In the following example, how do I set separate ylims for each of my facets?</p>
  
  <pre><code>qplot(x, value,  data=df, geom=c("smooth")) + facet_grid(variable ~ ., scale="free_y")
  </code></pre>
  
  <p>In each of the facets, the y-axis takes a different range of values and I would like to different ylims for each of the facets.</p>
  
  <p>The defaults ylims are too long for the trend that I want to see.</p>