# Simulation der SBD Daten #
# ======================== #

set.seed(123)

Ji <- rep(6, 30)
n <- sum(Ji)
I <- length(Ji)
ID <- rep(1:I, Ji)
gender <- 1 * (ID > 15)
dosis <- rep(c(10, 20, 40, 80, 120, 160), I)
RI <- rnorm(I, 10)
RS <- rnorm(I, sd = 0.09)
eps <- rnorm(n, sd = 2)

fun <- function(x){
  -2 * sqrt(x) - x/20
}

SBD <- 150 + fun(dosis) - 2 * gender - dosis * gender/100 + 
  RI[ID] + RS[ID] * dosis + eps

blutdruck <- data.frame(ID = ID, gender = gender, dosis = dosis, SBD = SBD)