Dear Muthen and team, I have used two substudies within a large longitudinal cohort to derive trajectories using the LCGA. To assess whether the results were robust, I subsequently repeated the same analysis in each one of the two studies separately. I was asked to provide the confusion matrix of study A vs B classes to support that my main results were robust. The information I have got was to use the study A-LCGA classifier to group the trajectories of the study B. That was not very clear to me and I could not find any additional information to help me with how to do that in Mplus. Your advice would be greatly appreciated.