This is a 2D projection of a ternary plot, showing the relative proportions (as percentages) of three variables on three axes;
in addition, it displays values of a 4th dimension using color-coded bubbles
The bubble marker size can be displayed proportional to bubble values or log of bubble values.
It allows the use of round or square shaped bubbles, and has the option of plotting the chart clockwise or counterclockwise.
A Ternary Bubble Chart Displaying Values of a 4th Variable by Color-Coded Bubbles