K-Means Cluster Analysis Iterate

Note: These options are available only if you select the Iterate and classify method from the K-Means Cluster Analysis dialog box.

Maximum Iterations. 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 reproduce 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 minimum 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 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 all cases have been assigned.

Specifying Iteration Settings

This feature requires the Statistics Base option.

  1. From the menus choose:

    Analyze > Classify > K-Means Cluster...

  2. In the K-Means Cluster dialog box, click Iterate.