The GLIMMIX Procedure


By default, all models automatically include a column of 1s in $\mb{X}$ to estimate a fixed-effect intercept parameter. You can use the NOINT option in the MODEL statement to suppress this intercept. The NOINT option is useful when you are specifying a classification effect in the MODEL statement and you want the parameter estimates to be in terms of the (linked) mean response for each level of that effect, rather than in terms of a deviation from an overall mean.

By contrast, the intercept is not included by default in $\bZ $. To obtain a column of 1s in $\bZ $, you must specify in the RANDOM statement either the INTERCEPT effect or some effect that has only one level.