Can you please clarify where the random effects covariance structure is specified in the source code? I would like to specify the variance-covariance structure of 6 random effects parameters as shown below. This is a modified version of the Toeplitz covariance structure that can be implemented in SAS PROC MIXED. I have spent several hours sorting through the source code but have been unsuccessful in modifying the code to permit this covariance structure. Any assistance would be greatly appreciated!
Hello,
Can you please clarify where the random effects covariance structure is specified in the source code? I would like to specify the variance-covariance structure of 6 random effects parameters as shown below. This is a modified version of the Toeplitz covariance structure that can be implemented in SAS PROC MIXED. I have spent several hours sorting through the source code but have been unsuccessful in modifying the code to permit this covariance structure. Any assistance would be greatly appreciated!