In the following code I would like to test whether the random farm effect can be removed from the model, whether the repeatedly measured response = score on the subjects=animals is independent from the farm effect, respectively.
As I understand this can be done in Proc Glimmix by using the covtest statement, which can be specified multiple times. http://support.sas.com/documentation/cdl/en/statug/63033/HTML/default/viewer.htm#statug_glimmix_sect...
But it does not work as done below, the procedure does not consider the covtest statement. I am using SAS 9.2.
What's wrong with the syntax? How can I obtain statistical inference on the random farm effect in proc glimmix ?
proc glimmix data=x METHOD=LAPLACE;
class farm genotype animal;
model score = genotype sweek genotype*sweek /
dist=multinomial link=cumlogit solution;
random int / subject=farm solution;
random int sweek / subject=animal solution;
I assume you have 9.2 or 9.22, and that the Log does not give an error (like unknown statement). When you say not active, do you mean that there is no output table generated with the test of the variance? If that is true, you will need to contact SAS Technical Support -- could be a problem with your installation.
Sorry for the confusion with the word "active". Yes, you are right, the log does not give an error and there is no output table for the tests of covariance parameters, though the farm variance is listed first in the output table for covariance parameter estimates.
I use SAS 9.2.