title: How to converte data frame to stacked barplot? (R)
body: <p>I have this matrix</p>
  <p>(<img src="https://i.stack.imgur.com/QnIEb.png" alt="enter image description here" />)</p>
  <p>that I converted to data frame.
  But now I want to do stacked bar plot that - in the first bar will be: 4 R, 3 S and 2 T (in percentage), in the second bar will be: 31 R, 10 H....</p>
  <p>I have trouble with how to make bar for every column..</p>
  <p>thanks!</p>