Hi Is there any way to fit a bivaraite longitudinal mixed model using R. I have a data set with col names
resp1 (Y_ij1), resp2 (Y_ij2), timepts (t_ij), unit(i) j=1,2,..,m and i=1,2,..n. I want to fit the following two models Model 1 Y_ij1, Y_ij2 | U_i = u_i ~ N(alpha + u_i + beta1*t_ij, Sigma) U_i ~ iid N(0, sigu^2) Sigma = bivariate AR structure alpha and beta are vectors of order 2. Model 2 Y_ij, Y_ij2 | U_i = u_i ~ N(alpha + u_i + beta1*t_ij + U_i2*t_ij, Sigma) U_i=(U_i1,U_i2) ~ iid N(0, Omega) Sigma =bivariate AR structure Here alpha and beta are vectors of order 2. Moreover can we assume a structure for Omega. Any help is greatly appreciated. Souvik Banerjee Junior Research Fellow Dept of Statistics University of calcutta [[alternative HTML version deleted]] ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.