SPSS® 12.0 Command Syntax Reference

LOGLINEAR 821
• To enter cell covariates into a model, the covariates must be specified on the DESIGN subcommand.
• Cell covariates are not applied on a case-by-case basis. The mean covariate value for a
cell in the contingency table is applied to that cell.
Example
LOGLINEAR DPREF(2,3) RACE CAMP (1,2) WITH CONSTANT
/DESIGN=DPREF RACE CAMP CONSTANT.
• Variable CONSTANT is a continuous variable specified as a cell covariate. Cell covariates
must be specified after the keyword WITH following the variable list. No range is defined
for cell covariates.
• To include the cell covariate in the model, variable CONSTANT is specified on DESIGN.
CWEIGHT Subcommand
CWEIGHT specifies cell weights, such as structural zeros, for a model. By default, cell
weights are equal to 1.
• The specification is either one numeric variable or a matrix of weights enclosed in
parentheses.
• If a matrix of weights is specified, the matrix must contain the same number of elements
as the product of the levels of the categorical variables. An asterisk can be used to signify
repetitions of the same value.
• If weights are specified for a multiple-factor model, the index value of the rightmost
factor increments the most rapidly.
• If a numeric variable is specified, only one CWEIGHT subcommand can be used on
LOGLINEAR.
• To use multiple cell weights on the same LOGLINEAR command, specify all weights in
matrix format. Each matrix must be specified on a separate CWEIGHT subcommand, and
each CWEIGHT specification remains in effect until explicitly overridden by another
CWEIGHT subcommand.
• CWEIGHT can be used to impose structural, or a priori, zeros on the model. This feature
is useful in the analysis of symmetric tables.
Example
COMPUTE CWT=1.
IF (HUSED EQ WIFED) CWT=0.
LOGLINEAR HUSED WIFED(1,4) WITH DISTANCE
/CWEIGHT=CWT
/DESIGN=HUSED WIFED DISTANCE.
• COMPUTE initially assigns CWT the value 1 for all cases.
• IF assigns CWT the value 0 when HUSED equals WIFED.