# NOT RUN {
if (require("sandwich")) {
  # robust standard errors, calling sandwich::vcovHC(type="HC3") by default
  model <- lm(Petal.Length ~ Sepal.Length * Species, data = iris)
  standard_error_robust(model)
}
if (require("clubSandwich")) {
  # cluster-robust standard errors, using clubSandwich
  iris$cluster <- factor(rep(LETTERS[1:8], length.out = nrow(iris)))
  standard_error_robust(
    model,
    vcov_type = "CR2",
    vcov_args = list(cluster = iris$cluster)
  )
}
# }
Run the code above in your browser using DataLab