SPSS® 12.0 Command Syntax Reference

Optional output. You can request optional output through the PRINT subcommand.
CATPCA 191
Optional plots. You can request a plot of object points, transformation plots per variable, and
plots of category points per variable or a joint plot of category points for specified variables.
Other plot options include residuals plots, a biplot, a triplot, component loadings plot, and a
plot of projected centroids.
Writing discretized data, transformed data, object (component) scores, and approximations. You
can write the discretized data, transformed data, object scores, and approximations to
external files for use in further analyses.
Saving transformed data, object (component) scores, and approximations. You can save the transformed
variables, object scores, and approximations to the working data file.
Basic Specification
The basic specification is the CATPCA command with the VARIABLES and ANALYSIS
subcommands.
Syntax Rules
• The VARIABLES and ANALYSIS subcommands must always appear, and the VARIABLES
subcommand must be the first subcommand specified. The other subcommands can be
specified in any order.
• Variables specified in the ANALYSIS subcommand must be found in the VARIABLES
subcommand.
• Variables specified in the SUPPLEMENTARY subcommand must be found in the
ANALYSIS subcommand.
Operations
Limitations
• If a subcommand is repeated, it causes a syntax error and the procedure terminates.
• CATPCA operates on category indicator variables. The category indicators should be
positive integers. You can use the DISCRETIZATION subcommand to convert fractionalvalue
variables and string variables into positive integers.
• In addition to system-missing values and user-defined missing values, CATPCA treats
category indicator values less than 1 as missing. If one of the values of a categorical
variable has been coded 0 or a negative value and you want to treat it as a valid category,
use the COMPUTE command to add a constant to the values of that variable such that the
lowest value will be 1 (see the COMPUTE command or the SPSS Base User’s Guide for
more information on COMPUTE). You can also use the RANKING option of the