R/boot_ci_parallel.R

In AMUFacultyOfEnglish/ENRanalytics: A package facilitating common E&R data processing tasks

#' Compute confidence interval by Mikolaj Olszewski (using foreach)
#' 
#' @param data A vector
#' @param FUN The function to be applied:
#' @param rep Number of repetition. Default value: 10000

boot_ci_parallel <- function(data, FUN, rep = 10000) {
  cl <- makeCluster(4)
  registerDoParallel(cl)
  res <- foreach(icount(rep)) %dopar% {
    d2 = sample(data, replace = TRUE)
    r = FUN(d2)
    r
  }
  
  stopCluster(cl)
  res <- unlist(res)
  val = FUN(data)
  q = quantile(res, probs = c(0.025, 0.975))
  return(list(
    min = q[1],
    val = val,
    max = q[2],
    se = sd(res)
  ))
}