I'm using a gxe in the presence of rge model and was wondering if I need to first run an unretricted baseline model to determine the minimized value of -2lnL of the data. If so, does anyone have a script for this?
I do not think I can use a bivariate unrestricted baseline model for this as I am using the gxe in the presence of rge in an atypical way. I am including two traits (continuous variables) and one moderator (categorical variable) so that I can examine the influence of the moderator on the covariance between the two traits. Given the altered use of the model, I wasn't sure if I need to (or can) run an unrestricted baseline model first.