PROC MIXED MODEL Statement Options

Processes | Predictive Modeling | PROC MIXED MODEL Statement Options

PROC MIXED MODEL Statement Options

Enter SAS PROC MIXED MODEL statement options in this field to override default parameters.

The MODEL statement names a single dependent variable and the fixed effects , which determine the X matrix of the mixed model .

You can specify any PROC MIXED MODEL option using the following syntax:

dependent = <fixed-effects></options>

where:

•

dependent is a single dependent variable,

•

< fixed-effects > consists of a variable or combination of variables that have a fixed number of levels. Refer to Specification of Effects for instructions on specifying effects.

•

</options> specify model building parameters, tolerances, and statistical computations and output.

Examples of commonly used PROC MIXED MODEL options are listed in the following table:

Option

Definition

ALPHA= number

This option requests that a t -type confidence interval be constructed for each of the fixed-effects parameters with confidence level 1-number . The value of number must be between 0 and 1; the default is 0.05.

CHISQ

This option requests chi-square tests be performed for all specified effects in addition to the F tests. Type 3 tests are the default; you can produce the Type 1 and Type 2 tests by using the HTYPE= option.

CL

This option requests that t -type confidence limits be constructed for each of the fixed-effects parameter estimates. The confidence level is 0.95 by default; this can be changed with the ALPHA= option.

ZETA=

This option tunes the sensitivity in forming Type 3 functions. Any element in the estimable function basis with an absolute value less than number is set to 0. The default is 1E-8 .

To Specify One or More PROC MIXED MODEL Statement Options:

Type specific PROC MIXED MODEL options in the PROC MIXED MODEL Statement Options field.

For example, to produce the approximate correlation matrix of the fixed-effects parameter estimates for the dependent variable Disease as affected by gender, type Disease=Sex/CORRB , as shown below:

For Additional Information

Refer to the SAS PROC MIXED MODEL Statement documentation for more information.

Option	Definition
ALPHA= number	This option requests that a t -type confidence interval be constructed for each of the fixed-effects parameters with confidence level 1-number . The value of number must be between 0 and 1; the default is 0.05.
CHISQ	This option requests chi-square tests be performed for all specified effects in addition to the F tests. Type 3 tests are the default; you can produce the Type 1 and Type 2 tests by using the HTYPE= option.
CL	This option requests that t -type confidence limits be constructed for each of the fixed-effects parameter estimates. The confidence level is 0.95 by default; this can be changed with the ALPHA= option.
ZETA=	This option tunes the sensitivity in forming Type 3 functions. Any element in the estimable function basis with an absolute value less than number is set to 0. The default is 1E-8 .