title: Alternative to venn diagram
body: <p>Is there a visualization format that shows overlapping proportion of categories in data, but more precise than venn diagram? Also venn diagram is typically used to show 2 or 3 categories, more than that it gets confusing. </p>
  
  <p>Stacked bar, waterfall etc could show proportion per categories, but assuming no overlapping between these categories. </p>
  
  <p>So for overlapping categories, what's the best way to show their proportion, including the proportion that overlaps with another category?</p>