User Guide

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Chapter 33
K-Means Clus
ter Analysis Iterate
Figure 33-3
K-Means Cluster Analysis Iterate dialog box
These options are available only if you select the Iterate and Classify method from the
main dialog box.
Maximum It
erations.
Limits the number of iterations in the k-means algorithm.
Iteration stops after this many iterations even if the convergence criterion is not
satisfied. This number must be between 1 and 999.
To reprod
uce the algorithm used by the Quick Cluster command prior to version 5.0,
set Maximum Iterations to 1.
Convergence Criterion. Determines when iteration ceases. It represents a proportion of
the minim
um distance between initial cluster centers, so it must be greater than 0 but
not greater than 1. If the criterion equals 0.02, for example, iteration ceases when a
complete iteration does not move any of the cluster centers by a distance of more than
2% of the
smallest distance between any of the initial cluster centers.
Use running means. Allows you to request that cluster centers be updated after each
case is assigned. If you do not select this option, new cluster centers are calculated
after al
l cases have been assigned.
K-Means Cluster Analysis Save
Figure 33-4
K-Means Cluster Analysis Save New Variables dialog box