title: Creating stacked barplots in R using different variables
body: <p>I am a novice R user, hence the question. I refer to the solution on creating stacked barplots from <a href="https://stackoverflow.com/questions/2619069/r-programming-creating-a-stacked-bar-graph-with-variable-colors-for-each-stack">R programming: creating a stacked bar graph, with variable colors for each stacked bar</a>.</p>
  
  <p>My issue is slightly different. I have 4 column data. The last column is the summed total of the first 3 column. I want to plot bar charts with the following information 1) the summed total value (ie 4th column), 2) each bar is split by the relative contributions of each of the three column.</p>
  
  <p>I was hoping someone could help.</p>
  
  <p>Regards,
  Bernard</p>