title: Circular Heatmap that looks like a donut
body: <p>I'm trying to create circular heatmap with ggplot2 so I can use a larger number of labels
  around the circumference of a circle. I'd like to have it look more like a donut with an empty hole in the middle but at the same time not losing any rows (they would need to be compressed).</p>
  
  <p>Code for what I have is below.</p>
  
  <pre><code>library(reshape)
  library(ggplot2)
  
  nba &lt;- read.csv("http://datasets.flowingdata.com/ppg2008.csv")
  
  nba$Name &lt;- with(nba, reorder(Name, PTS))
  nba.m &lt;- melt(nba)
  nba.m &lt;- ddply(nba.m, .(variable), transform, value = scale(value))
  
  
  p = ggplot(nba.m, aes(Name,variable)) + geom_tile(aes(fill = value), colour = "white") +           scale_fill_gradient(low = "white", high = "steelblue") 
  p&lt;-p+opts(
  panel.background=theme_blank(),
  axis.title.x=theme_blank(),
  axis.title.y=theme_blank(),
  panel.grid.major=theme_blank(),
  panel.grid.minor=theme_blank(),  
  axis.text.x=theme_blank(),
  axis.ticks=theme_blank()
  )
  
  
  p = p + coord_polar() 
  plot(p) 
  </code></pre>