SPSS® 12.0 Command Syntax Reference

240 CLUSTER
• This example produces a vertical icicle plot for every fifth cluster solution starting with
1 and ending with 151 (1 cluster, 6 clusters, 11 clusters, and so on).
MISSING Subcommand
MISSING controls the treatment of cases with missing values. A case that has a missing value
for any variable on the variable list is omitted from the analysis. By default, user-missing
values are exlcuded from the analysis.
EXCLUDE Exclude cases with user-missing values. This is the default.
INCLUDE Include cases with user-missing values. Only cases with system-missing
values are excluded.
MATRIX Subcommand
MATRIX reads and writes SPSS-format matrix data files.
• Either IN or OUT and a matrix file in parentheses are required. When both IN and OUT are
used on the same CLUSTER procedure, they can be specified on separate MATRIX subcommands
or on the same subcommand.
• The input or output matrix information is displayed in the procedure information notes.
OUT (filename) Write a matrix data file. Specify either a filename or an asterisk in parentheses
(*). If you specify a filename, the file is stored on disk and can be retrieved at
any time. If you specify an asterisk (*), the matrix data file replaces the
working data file but is not stored on disk unless you use SAVE or XSAVE.
IN (filename) Read a matrix data file. If the matrix data file is the current working data file,
specify an asterisk (*) in parentheses. If the matrix data file is another file,
specify the filename in parentheses. A matrix file read from an external file
does not replace the working data file.
When an SPSS Matrix is produced using the MATRIX OUT subcommand, it corresponds to a
unique data set. All subsequent analyses performed on this matrix would match the corresponding
analysis on the original data. However, if the data file is altered in any way, this
would no longer be true.
For example, if the original file is edited or rearranged it would in general no longer correspond
to the initially produced matrix. You need to make sure that the data match the matrix
whenever inferring the results from the matrix analysis. Specifically, when saving the cluster
membership into a working data file in the CLUSTER procedure, the proximity matrix in the
MATRIX IN statement must match the current working data file.
Matrix Output
• CLUSTER writes proximity-type matrices with ROWTYPE_ values of PROX. CLUSTER
neither reads nor writes additional statistics with its matrix materials. See “Format of the
Matrix Data File” below for a description of the file.