SPSS® 12.0 Command Syntax Reference

212 Syntax Reference
SPORD and SPNOM Keywords
NUME Numerical. Categories are treated as equally spaced (interval level).
The order of the categories and the differences between category numbers
of the observed variables are preserved in the optimally scaled
variable. Categories will be on a straight line through the origin. When
all variables are scaled at the numerical level, the CATREG analysis is
analogous to standard multiple regression analysis.
The following keywords are used with SPORD and SPNOM :
DEGREE The degree of the polynomial. If DEGREE is not specified the degree
is assumed to be 2.
INKNOT The number of the interior knots. If INKNOT is not specified the number
of interior knots is assumed to be 2.
DISCRETIZATION Subcommand
DISCRETIZATION specifies fractional-value variables that you want to discretize. Also, you
can use DISCRETIZATION for ranking or for two ways of recoding categorical variables.
• A string variable’s values are always converted into positive integers by assigning
category indicators according to the ascending alphanumeric order. DISCRETIZATION for
string variables applies to these integers.
• When the DISCRETIZATION subcommand is omitted, or when the DISCRETIZATION subcommand
is used without a varlist, fractional-value variables are converted into positive
integers by grouping them into seven categories (or into the number of distinct values of
the variable if this number is less than 7) with a close to normal distribution.
• When no specification is given for variables in a varlist following DISCRETIZATION, these
variables are grouped into seven categories with a close-to-normal distribution.
• In CATREG, a system-missing value, user-defined missing values, and values less than 1
are considered to be missing values (see next section). However, in discretizing a
variable, values less than 1 are considered to be valid values, and are thus included in the
discretization process. System-missing values and user-defined missing values are
excluded.
GROUPING Recode into the specified number of categories.
RANKING Rank cases. Rank 1 is assigned to the case with the smallest value on
the variable.
MULTIPLYING Multiplying the standardized values (z-scores) of a fractional-value
variable by 10, rounding, and adding a value such that the lowest
value is 1.