title: Waterfall plot with emphasizing select points
body: <p>I would like to make a nice waterfall plot emphasizing select points -- in R you can generate a waterfall plot as follows:</p>
  
  <p>Imagine a sequence of numbers from 2 to -2, as follows:</p>
  
  <pre><code>m = seq (from=2.0 ,to=-2.0,by= -0.05)
  barplot(m)
  </code></pre>
  
  <p>This results in an array of 81 points</p>
  
  <pre><code>&gt;m
  #[1]  2.00  1.95  1.90  1.85  1.80  1.75  1.70  1.65  1.60  1.55  1.50  1.45
  #[13]  1.40  1.35  1.30  1.25  1.20  1.15  1.10  1.05  1.00  0.95  0.90  0.85
  #[25]  0.80  0.75  0.70  0.65  0.60  0.55  0.50  0.45  0.40  0.35  0.30  0.25
  #[37]  0.20  0.15  0.10  0.05  0.00 -0.05 -0.10 -0.15 -0.20 -0.25 -0.30 -0.35
  #[49] -0.40 -0.45 -0.50 -0.55 -0.60 -0.65 -0.70 -0.75 -0.80 -0.85 -0.90 -0.95
  #[61] -1.00 -1.05 -1.10 -1.15 -1.20 -1.25 -1.30 -1.35 -1.40 -1.45 -1.50 -1.55
  #[73] -1.60 -1.65 -1.70 -1.75 -1.80 -1.85 -1.90 -1.95 -2.00
  </code></pre>
  
  <p>What I would like to do is emphasize say points m[13] and m[37] by giving it a different color and potentially displaying the barplot in 3D.</p>
  
  <p>Anyone have any ideas of how to do this?</p>
  
  <p>I am using ggbio these days and believe there must be a way -- say with an S4 object to achieve the an object which then I could use with autoplot.  </p>
  
  <p>Anyone clever enough out there to have this figured out?</p>