Modeling and Multivariate Methods - SAS

472 Clustering Data Chapter 18
K-Means Clustering
K-Means Platform Options
These options are accessed from the red-triangle menus, and apply to KMeans, Normal Mixtures, Robust
Normal Mixtures, and Self-Organizing Map methods.
Biplot shows a plot of the points and clusters in the first two principal components of the data. Circles are
drawn around the cluster centers. The size of the circles are proportional to the count inside the cluster.
The shaded area is the 90% density contour around the mean, therefore the shaded area indicates where
90% of the observations in that cluster would fall. Below the plot is an option to save the cluster colors
to the data table.
Biplot Options contains options for controlling the Biplot.
Show Biplot Rays allows you to show or hide the biplot rays.
Biplot Ray Position allows you to position the biplot ray display. This is viable since biplot rays only
signify the directions of the original variables in canonical space, and there is no special significance to
where they are placed in the graph.
Mark Clusters assigns markers to the rows of the data table corresponding to the clusters.
Biplot 3D
shows a three-dimensional biplot of the data. Three variables are needed to use this option.
Parallel Coord Plots creates a parallel coordinate plot for each cluster. For details about the plots, see
Basic Analysis and Graphing. The plot report has options for showing and hiding the data and means.
Scatterplot Matrix
creates a scatterplot matrix using all the variables.
Save Colors to Table
colors each row with a color corresponding to the cluster it is in.
Save Clusters creates a new column with the cluster number that each row is assigned to. For normal
mixtures, this is the cluster that is most likely.
Save Cluster Formula
creates a new column with a formula to evaluate which cluster the row belongs to.
Save Mixture Probabilities creates a column for each cluster and saves the probability an observation
belongs to that cluster in the column. This is available for Normal Mixtures and Robust Normal
Mixtures clustering only.
Save Mixture Formulas creates columns with mixture probabilities, but stores their formulas in the
column and needs additional columns to hold intermediate results for the formulas. Use this feature if
you want to score probabilities for excluded data, or data you add to the table. This is available for
Normal Mixtures and Robust Normal Mixtures clustering only.
Save Density Formula
clustering only.
saves the density formula in the data table. This is available for Normal Mixtures
Simulate Clusters creates a new data table containing simulated clusters using the mixing probabilities,
means, and standard deviations.
Remove
removes the clustering report.