title: geom_bar with multiple fill colour in ggplot2
body: <p>I have this kind of dataset :</p>
  
  <pre><code>comb&lt;-data.frame(nom=c("A","B","C","A","B","C"),type=c(rep("1",3),rep("2",3)),val=c(1,3,2,3,2,2))
  </code></pre>
  
  <p>I Would like to have this result with <code>ggplot2</code>:</p>
  
  <p><img src="https://i.stack.imgur.com/v34eg.png" alt="enter image description here"></p>
  
  <p>But I just have this</p>
  
  <pre><code>ggplot()+    geom_bar(data=comb,aes(x=nom, y=val,fill=type),stat='identity',position='dodge')
  </code></pre>
  
  <p><img src="https://i.stack.imgur.com/Ggqll.png" alt="enter image description here"></p>
  
  <p>Do you have any solution for me?</p>