title: geom_bar with multiples variables
body: <p>I'm working in R studio and I'm trying to make a bar chart with 4 different variables on the X axis, and the proportion of each variable observation on the Y axis. My data looks like this:</p>
  <pre><code>A B C D
  1 5 9 0
  2 5 9 0
  1 5 8 0
  1 6 8 0
  </code></pre>
  <p>I've tinkered with this code:</p>
  <pre><code>ggplot(data) +
    geom_bar(mapping = aes(x= A), position = &quot;fill&quot;)+
    geom_bar(mapping = aes(x= B), position = &quot;fill&quot;)+
    geom_bar(mapping = aes(x= C), position = &quot;fill&quot;)+
    geom_bar(mapping = aes(x= D), position = &quot;fill&quot;)
  </code></pre>
  <p>What I keep ending up with on the X axis is:</p>
  <p>1 2 5 6 9 8 0</p>
  <p>What I'm trying to put on the X axis is:</p>
  <p>A B C D</p>
  <p>I appreciate any help you can offer!</p>