title: How to plot a confusion matrix using heatmaps in R?
body: <p>I have a confusion matrix such that:</p>
  
  <pre><code>  a b c d e f g h i j
  a 5 4 0 0 0 0 0 0 0 0
  b 0 0 0 0 0 0 0 0 0 0
  c 0 0 4 0 0 0 0 0 0 0
  d 0 0 0 0 0 0 0 0 0 0
  e 2 0 0 0 2 0 0 0 0 0
  f 1 0 0 0 0 2 0 0 0 0
  g 0 0 0 0 0 0 0 0 0 0
  h 0 0 0 0 0 0 0 0 0 0 
  i 0 0 0 0 0 0 0 0 0 0 
  j 0 0 0 0 0 0 0 0 0 0 
  </code></pre>
  
  <p>where the letters denote the class labels.</p>
  
  <p>I just need to plot the confusion matrix. I searched a couple of tools. Heatmaps in R looks like what I need. As I don't know anything about R, it is really hard to do changes on the samples. If anybody could help me shortly how to draw, I will be really appreciated. Or any other suggestion rather than heatmaps are welcome as well. 
  I know there is plenty of samples about this, but still I cannot manage to draw with my own data.</p>