title: facet ordering in multilevel ggplot stacked barplot
body: <p>I would like to order the facets within each bar in a decreasing manner -&gt; highest value first, then next, then next....</p>
  <p>A simple example would be the following:</p>
  <pre><code>library(ggplot) 
  library(forcats)
  
  mpgtest &lt;- mpg 
  
  mpgtest$class &lt;- fct_reorder2(mpgtest$class, mpgtest$manufacturer, mpgtest$cyl)
  
  ggplot(mpgtest, aes(x=manufacturer, y = cyl, fill = class)) +
  geom_col() +
  facet_wrap(.~year)
  </code></pre>
  <p>In the example, the stacks are not ordered correctly.</p>