Categorized Ternary Graphs

Graphical Analytic Techniques

Ribbon bar. Select the Graphs tab. In the More group, click Categorized and from the menu select 3D Ternary Plots to display the Categorized Ternary Graphs Startup Panel.

Classic menus. On the Graphs - Categorized Graphs submenu, select 3D Ternary Plots to display the Categorized Ternary Graphs Startup Panel.

You can create a series of ternary graphs, one for each category of cases identified by the X or X and Y category variables (or identified by the Multiple Subsets option button on the Advanced tab).

A categorized ternary plot can be used to examine relations between three or more dimensions where three of those dimensions represent components of a mixture (i.e., the relations between them is constrained such that the values of the three variables add up to the same constant for each case) for each level of a grouping variable. One typical application of this graph is when the measured response(s) from an experiment depends on the relative proportions of three components (e.g., three different chemicals) which are varied in order to determine an optimal combination of those components (e.g., in mixture designs). In a categorized ternary plot, one component graph is produced for each level of the grouping variable (or user-defined subset of data) and all the component graphs are arranged in one display to allow for comparisons between the subsets of data (categories).

In ternary plots, the triangular coordinate systems are used to plot four (or more) variables (the components X, Y, and Z, and the responses V1, V2, etc.) in two dimensions (ternary scatterplots or contours) or three dimensions (ternary surface plots). In order to produce ternary graphs, the relative proportions of each component within each case are constrained to add up to the same value (e.g., 1). By default, when the graph is produced, the proportions are rescaled so that they add to 1 in each case. Other options to manage cases with invalid sums are given below (see Data range on the Advanced tab).

The Categorized Ternary Graphs Startup Panel contains five tabs: Quick, Advanced, Appearance, Options 1, and Options 2. The following options are available regardless of which tab is selected.