Modeling and Multivariate Methods - SAS

580 Visualizing, Optimizing, and Simulating Response Surfaces Chapter 24
Mixture Profiler
Many of the features shown are the same as those of the Contour Profiler and are described on “Contour
Profiler Pop-up Menu” on page 578. Some of the features unique to the Mixture Profiler include:
• A ternary plot is used instead of a Cartesian plot. A ternary plot enables you to view three mixture
factors at a time.
• If you have more than three factors, use the radio buttons at the top left of the Mixture Profiler window
to graph other factors. For detailed explanation of radio buttons and plot axes, see “Explanation of
Ternary Plot Axes” on page 580
• If the factors have constraints, you can enter their low and high limits in the Lo Limit and Hi Limit
columns. This shades non-feasible regions in the profiler. As in Contour Plot, low and high limits can
also be set for the responses.
Figure 24.29 Mixture Profiler
radio buttons to
choose plot axes
Setting these
shades the area
outside limits
Explanation of Ternary Plot Axes
The sum of all mixture factor values in a mixture experiment is a constant, usually, and henceforth assumed
to be 1. Each individual factor’s value can range between 0 and 1, and three are represented on the axes of
the ternary plot.
For a three factor mixture experiment in which the factors sum to 1, the plot axes run from a vertex (where
a factor’s value is 1 and the other two are 0) perpendicular to the other side (where that factor is 0 and the
sum of the other two factors is 1). See Figure 24.30.
For example, in Figure 24.30, the proportion of p1 is 1 at the top vertex and 0 along the bottom edge. The
tick mark labels are read along the left side of the plot. Similar explanations hold for p2 and p3.