title: seaborn FacetGrid , ranked barplot separated on row and col
body: <p>Given some data:</p>
  
  <pre><code>pt = pd.DataFrame({'alrmV':[000,000,000,101,101,111,111],
                     'he':[e,e,e,e,h,e,e],
                     'inc':[0,0,0,0,0,1,1]})
  </code></pre>
  
  <p>I would like to create a bar plot separated on row and col.</p>
  
  <pre><code>g = sns.FacetGrid(pt, row='inc', col='he', margin_titles=True)
  g.map( sns.barplot(pt['alrmV']), color='steelblue')
  </code></pre>
  
  <p>This, works, but how do I also add:</p>
  
  <ol>
  <li>an ordered x-axis</li>
  <li>only display the top-two-by-count <code>alrmV</code> types</li>
  </ol>
  
  <p>To get an ordered x-axis, that displays the top 2 count types, I played around with this grouping, but unable to get it into a Facet grid:</p>
  
  <pre><code>grouped = pt.groupby( ['he','inc'] )
  grw= grouped['alrmV'].value_counts().fillna(0.) #.unstack().fillna(0.)
  grw[:2].plot(kind='bar')
  </code></pre>
  
  <p>Using FacetGrid, slicing limits the total count displayed </p>
  
  <pre><code>g.map(sns.barplot(pt['alrmV'][:10]), color='steelblue')
  </code></pre>
  
  <p>So how can I get a bar graph, that is separated on row and col, and is ordered and displays only top 2 counts?</p>