Multivariate Response Linear Mixed Effects

[mortonjt]

It would be nice to have a formal framework for multivariate response linear mixed effects

https://www.jstatsoft.org/article/view/v033i02/v33i02.pdf http://sci2s.ugr.es/keel/pdf/specific/articulo/schafer_yucel02.pdf http://www.bristol.ac.uk/media-library/sites/cmm/migrated/documents/mixed-multivariate-responses.pdf http://lme4.r-forge.r-project.org/lMMwR/lrgprt.pdf https://socserv.socsci.mcmaster.ca/jfox/Books/Companion/appendix/Appendix-Multivariate-Linear-Models.pdf

This will not only clean up the linear mixed effects code, but can allow for future avenues for analyzing correlations between response variables, imputation and possibly robustness