title: For geom_violin, how is the total area of all violins specified?
body: <p>In a call to <code>geom_violin</code> within <code>ggplot2</code>, you can specify that the area of each violin should be proportional to the number of observations making up that violin by specifying <code>scale="count"</code>.</p>
  
  <p>I assume this operates internally by taking some total amount of area (let's call this amount X) and dividing it proportionally among all violins to be plotted. This is what I want, except that this can result in pretty narrow violins if there is substantial enough disparity in N between groups such that some groups have relatively low N. In my case, this just makes the fill color kind of hard to see.</p>
  
  <p>I think this can be largely solved, in my case at least, by simply expanding X a little bit so that the really small violins get just enough area to still be readable. In other words, <strong>I want to retain variation in area between violins according to the number of observations but increase the "pool" of total area being divided amongst violins</strong>, so that every one gets slightly bigger. </p>
  
  <p>Anyone have any idea how one might accomplish this? There's gotta be a toggle for this. I've tried fussing with arguments to <code>geom_violin</code> such as <code>width</code>, <code>size</code>, <code>violinwidth</code>, and such, but no luck so far...</p>
  
  <p>EDIT: Code for a boring but reproducible "sample" data set that one can experiment with. </p>
  
  <pre><code>y = runif(100, 1, 10)
  x = as.factor(rep(c(1,2), times=50))
  z = as.factor(c(rep(1, 10), rep(2, 90)))
  df=data.frame(x, y, z)
  ggplot(df, aes(x=x, y=y, fill=z)) + geom_violin(scale="count")
  </code></pre>