title: Stacked barplot in UpSetR
body: <p>I have been looking for a way of having a stacked bar plot in an <a href="https://github.com/hms-dbmi/UpSetR" rel="noreferrer">upsetR</a> graph.
  I downloaded the movies data set (from <a href="https://gehlenborglab.shinyapps.io/upsetr/_w_02374609/movies.csv" rel="noreferrer">here</a>) and added a column having only two values "M" and "C".
  Below, information on how I loaded the data and added the "x" column.</p>
  
  <p><strong>Edit:</strong></p>
  
  <pre><code>m &lt;- read.csv(system.file("extdata", "movies.csv", package = "UpSetR"), 
                             header = T, sep = ";")
  nrow(m)
  [1] 3883
  x&lt;-c(rep("M", 3000), rep("C", 883))
  m&lt;-cbind(m, x)  
  unique(m$x)
  [1] M C
  </code></pre>
  
  <p>This is the structure of the data frame:</p>
  
  <pre><code>str(m)
  'data.frame':   3883 obs. of  22 variables:
   $ Name       : Factor w/ 3883 levels "$1,000,000 Duck (1971)",..: 3577 1858 1483 3718 1175 1559 3010 3548 3363 1420 ...
   $ ReleaseDate: int  1995 1995 1995 1995 1995 1995 1995 1995 1995 1995 ...
   $ Action     : int  0 0 0 0 0 1 0 0 1 1 ...
   $ Adventure  : int  0 1 0 0 0 0 0 1 0 1 ...
   $ Children   : int  1 1 0 0 0 0 0 1 0 0 ...
   $ Comedy     : int  1 0 1 1 1 0 1 0 0 0 ...
   $ Crime      : int  0 0 0 0 0 1 0 0 0 0 ...
   $ Documentary: int  0 0 0 0 0 0 0 0 0 0 ...
   $ Drama      : int  0 0 0 1 0 0 0 0 0 0 ...
   $ Fantasy    : int  0 1 0 0 0 0 0 0 0 0 ...
   $ Noir       : int  0 0 0 0 0 0 0 0 0 0 ...
   $ Horror     : int  0 0 0 0 0 0 0 0 0 0 ...
   $ Musical    : int  0 0 0 0 0 0 0 0 0 0 ...
   $ Mystery    : int  0 0 0 0 0 0 0 0 0 0 ...
   $ Romance    : int  0 0 1 0 0 0 1 0 0 0 ...
   $ SciFi      : int  0 0 0 0 0 0 0 0 0 0 ...
   $ Thriller   : int  0 0 0 0 0 1 0 0 0 1 ...
   $ War        : int  0 0 0 0 0 0 0 0 0 0 ...
   $ Western    : int  0 0 0 0 0 0 0 0 0 0 ...
   $ AvgRating  : num  4.15 3.2 3.02 2.73 3.01 3.88 3.41 3.01 2.66 3.54 ...
   $ Watches    : int  2077 701 478 170 296 940 458 68 102 888 ...
   $ x          : Factor w/ 2 levels "M","C": 1 1 1 1 1 1 1 1 1 1 ...
  </code></pre>
  
  <p>Now I tried to implement the stacked bar plot as follow:</p>
  
  <pre><code>upset(m,
    queries = list(
      list(query = elements, 
           params = list("x", "M"), color = "#e69f00", active = T),
      list(query = elements, 
           params = list("x", "C"), color = "#cc79a7", active = T)))
  </code></pre>
  
  <p>The result looks like this:</p>
  
  <p><a href="https://i.stack.imgur.com/zHoCa.png" rel="noreferrer"><img src="https://i.stack.imgur.com/zHoCa.png" alt="enter image description here"></a></p>
  
  <p>As you can see the proportions are wrong as there should be in each bar only two colors (factor) either "M" or "C".
  This issue seems to be not a trivial one, as also pointed out <a href="https://github.com/hms-dbmi/UpSetR/issues/59" rel="noreferrer">here</a>. 
  Does anyone have an idea on how to implement this in UpsetR?
  Thanks a lot</p>