batch {SimEngine}

Run a block of code as part of a batch

Description

This function is useful for sharing data or objects between simulation replicates. Essentially, it allows simulation replicates to be divided into “batches”; all replicates in a given batch will then share a certain set of objects. A common use case for this is a simulation that involves using multiple methods to analyze a shared dataset, and repeating this process over a number of dataset replicates. See the Advanced Functionality vignette for a detailed overview of how this function is used.

Usage

batch(code)

Arguments

code

A block of code enclosed by curly braces {}; see examples.

Examples

sim <- new_sim()
create_data <- function(n, mu) { rnorm(n=n, mean=mu) }
est_mean <- function(dat, type) {
  if (type=="est_mean") { return(mean(dat)) }
  if (type=="est_median") { return(median(dat)) }
}
sim %<>% set_levels(n=c(10,100), mu=c(3,5), est=c("est_mean","est_median"))
sim %<>% set_config(
  num_sim = 2,
  batch_levels = c("n","mu"),
  return_batch_id = TRUE
)
sim %<>% set_script(function() {
  batch({
    dat <- create_data(n=L$n, mu=L$mu)
  })
  mu_hat <- est_mean(dat=dat, type=L$est)
  return(list(
    "mu_hat" = round(mu_hat,2),
    "dat_1" = round(dat[1],2)
  ))
})
sim %<>% run()
sim$results[order(sim$results$batch_id),]