title: Using lattice to plot histograms of sorted categorical data
body: <p>Consider the following data file:</p>
  
  <pre><code>column_name
  foo
  foo
  bar
  baz
  baz
  bar
  foo
  baz
  </code></pre>
  
  <p>How I can plot a histogram with using the lattice package, and sorting by a custom order (not alphabetic), e.g.: <code>c('baz', 'foo', 'bar')</code>?</p>