Complete the following steps to specify the variables that you want to graph.
From Response, select the response variable that you want to plot.
Under Trace Direction, choose how to define the trace direction. If the reference point lies at the centroid, which is the default, the choice of the trace direction produces a difference in the plot only when the design space is constrained. For more information, go to Cox's and Piepel's component directions through the design space.
Cox (proportion): When the design space is constrained, Cox uses the vertex where the component is maximized over the unconstrained simplex.
Piepel (pseudocomponent): When the design is constrained, Piepel's direction is defined in the L-pseudocomponent space. The direction is the line connecting the reference blend to the vertex where the component is maximized (i.e. equal to 1) in pseudocomponent units.