Data
====

1. hiv.data.R
  - J        : number of people
  - N        : number of observations
  - person   : person number
  - time     : time measurements were taken
  - treatment: received treatment? 1: Yes, 0: No
  - y        : measurements of immune system of child

Models
======

1. Multilevel model with varying intercept and slope
  hiv.stan: lmer(y ~ 1 + (1 + time | person))

2. Multilevel model with group level predictors and interaction
  hiv_inter.stan: lmer(y ~ time:treatment + (1 + time | person))

3. Above models with Matt trick
  hiv_chr.stan      : lmer(y ~ 1 + (1 + time | person))
  hiv_inter_chr.stan: lmer(y ~ time:treatment + (1 + time | person))