The Ternary Plot option in the Graph menu produces a three-axis plot.
Ternary plots are a way of displaying the distribution and variability of three-part compositional data. (For example, the proportion of sand, silt, and clay in soil or the proportion of three chemical agents in a trial drug.) You can use data that is expressed in proportions or use absolute measures.
The ternary display is a triangle with sides that are scaled from 0 to 1. Each side represents one of the three components. A point is plotted so that a line that is drawn perpendicular from the point to each leg of the triangle intersects at the component values of the point.
Figure 11.1 Examples of Ternary PlotsĀ