SPSS® 12.0 Command Syntax Reference

Example
Overview
Options
CLUSTER V1 TO V4
/PLOT=DENDROGRAM
/PRINT=CLUSTER (2,4).
CLUSTER 227
CLUSTER produces hierarchical clusters of items based on distance measures of dissimilarity
or similarity. The items being clustered are usually cases from the working data file, and the
distance measures are computed from their values for one or more variables. You can also
cluster variables if you read in a matrix measuring distances between variables. Cluster analysis
is discussed in Anderberg (1973).
Cluster Measures and Methods. You can specify one of 37 similarity or distance measures on
the MEASURE subcommand and any of the seven methods on the METHOD subcommand.
New Variables. You can save cluster membership for specified solutions as new variables in
the working data file using the SAVE subcommand.
Display and Plots. You can display cluster membership, the distance or similarity matrix used
to cluster variables or cases, and the agglomeration schedule for the cluster solution with
the PRINT subcommand. You can request either a horizontal or vertical icicle plot or a dendrogram
of the cluster solution and control the cluster levels displayed in the icicle plot with
the PLOT subcommand. You can also specify a variable to be used as a case identifier in the
display on the ID subcommand.
Matrix Input and Output. You can write out the distance matrix and use it in subsequent
CLUSTER, PROXIMITIES, or ALSCAL analyses or read in matrices produced by other CLUSTER
or PROXIMITIES procedures using the MATRIX subcommand.
Basic Specification
The basic specification is a variable list. CLUSTER assumes that the items being clustered are
cases and uses the squared Euclidean distances between cases on the variables in the analysis
as the measure of distance.
Subcommand Order
• The variable list must be specified first.
• The remaining subcommands can be specified in any order.
Syntax Rules
• The variable list and subcommands can each be specified once.