I used "Area Proportional Ellipses" several years back which allowed up to three quantities to be represented. http://www.eulerdiagrams.org/eulerAPE/ http://ww

I used "Area Proportional Ellipses" several years back which allowed up to three quantities to be represented. http://www.eulerdiagrams.org/eulerAPE/ http://www.eulerdiagrams.org/eulerAPE/ I made multiple highly precise comparison figures... In the end someone (else) went into a paint program slapped a few ovals together as a cartoon of my precision which went into the final product because it did made a better illustration and conveyed to point of my figures without any accuracy beyond that of the mark-1 eyeball