Please also provide the following information in addition to your question:
- Operating System: debian 9
- brms Version: brms_2.8.0
Just trying brms for the first time so sorry if I’m asking something ignorant.
I wanted to know if there was a way to specify the variance structure of the residuals. I work on clonal organisms that I measure in different environments and treat the response variable as two separate responses (one for each environment in a 2 environment case).
At the group level I’m able to estimate the covariance between responses but as no individual organism is measured in both environments I can’t estimate the residual covariance.
When using programs such as asreml-R or MCMCglmm, I can use the idh() variance structure that estimates seperate residual variances for each response but not the covariance.
Is there an equivalent in brms?