


PROC GLIMMIX constructs a generalized linear mixed model according to the specifications in the CLASS
               , MODEL
               , and RANDOM
                statements. Each effect in the MODEL
                statement generates one or more columns in the matrix 
, and each G-side effect in the RANDOM
                statement generates one or more columns in the matrix 
. R-side effects in the RANDOM
                statement do not generate model matrices; they serve only to index observations within subjects. This section shows how the
               GLIMMIX procedure builds 
 and 
. You can output the 
 and 
 matrices to a SAS data set with the OUTDESIGN=
                option in the PROC GLIMMIX
                statement. 
            
The general rules and techniques for parameterization of a linear model are given in GLM Parameterization of Classification Variables and Effects in ChapterĀ 19: Shared Concepts and Topics. The following paragraphs discuss how these rules differ in a mixed model, in particular, how parameterization differs between
               the 
 and the 
 matrix.