The Plots Tab

You can use the Plots tab (Figure 30.4) to create plots that graphically display results of the analysis.

Creating a plot often adds one or more variables to the data table. The following plots are available:

Observed groups

creates a spine plot (a one-dimensional mosaic plot) of the groups for the Y variable.

Observed vs. Predicted groups

creates a mosaic plot of the groups for the Y variable versus the group as classified by a discriminant function. Each observation is placed in the group that minimizes the generalized squared distance between the observation and the group mean.

Classification fit plot

creates a plot that indicates how well each observation is classified by the discriminant function. This plot is shown in Figure 30.5. The observations selected in the plot have a low posterior probability of group membership. For each observation, PROC DISCRIM computes posterior probabilities for membership in each group. Let be the maximum posterior probability for the th observation. The classification fit plot is a plot of versus .