Merging clusters

The "Merge clusters" option allows you to merge two clusters into a single cluster, and then recalculate and draw the new cluster boundaries. If the two clusters are not adjacent, the boundaries will not be merged, but the clusters will appear the same (i.e., have the same color) on maps, will be assigned the same cluster number, and will be treated together in cluster statistics.

To merge two clusters:

  1. First, you must have generated clusters.

  2. Then, go to the "Data" menu, choose "Merge clusters."

  3. Identify the clusters you want to combine. You may wish to group clusters with similar values. To view the cluster statistics, go to the "Project" Menu, then choose "Table." Choose to view the "Cluster Statistics" for the data set. In this data set, the means and variances of all the variables are listed so that you can identify clusters with similar values. In addition, the number of elements in each cluster is listed, so you can identify "singleton" clusters that you may want to try to merge with other clusters. For more information on how to manipulate data in tables see Working with tables.

  4. Once you have chosen the clusters to combine, enter their cluster numbers on the pull-down list in the dialog.

  5. Select how you want to record the new clusters. After "Store revised clusters in" you have two choices: to overwrite the old clusters and boundaries by storing the new clusters in the "Existing data set and boundary" or to keep both files and create a "New data set" and "New boundaries." You can name the data set and boundaries or keep the default names BoundarySeer chooses.

  6. You can repeat this process to winnow the clusters to the desired number.

See also: