lme random-effect

  1. P

    Mathematical definition of random slope models

    Good morning everyone! I have implemented the following lme model in r: lme_mod<-lme(Value ~ Time+Treatment+Time*Treatment, random = ~ 1+Time| person_ID, method="ML", data=C) *Time is repeated 3 times for each patient (time=1,2,3) I am analyzing the following residuals: resid(lme_mod) Could...
  2. A

    Mixed model for time trend in R package lme4

    Hello! I would very much appreciate if anyone could help with my model in lme4. I have a dataset with 100 persons, specified by ID. Each of them was assessed at three time points, indicated by Time, for a specific measurement, called Score. I want to look at each person's trajectory over...
  3. C

    How is to define the lme model syntax .

    The following model assumes that the covariance between the random intercepts and random slopes across Subjects is Zero . lmer(Reaction ~ Days + (Days||Subject), sleepstudy) How can I write the same model by "lme" function under nlme pacakge assuming zero covariance between the random...
  4. D

    another way of using random effects

    Hello, I know it is a bit long but could someone please help me with this? I understand the concept of using a group ID as a random effect to allow variance within each group and therefore allow the use of multiple datum from each group. However, I am wondering whether they could be used in...