set_script: Set the "simulation script"

In Avi-Kenny/SimEngine: A Modular Framework for Statistical Simulations in R

Set the "simulation script"

Description

Specify a function to be used as the "simulation script". The simulation script is a function that runs a single simulation replicate and returns the results.

Usage

set_script(sim, fn)

Arguments

sim

A simulation object of class sim_obj, usually created by new_sim

fn

A function that runs a single simulation replicate and returns the results. The results must be a list of key-value pairs. Values are categorized as simple (a number, a character string, etc.) or complex (vectors, dataframes, lists, etc.). Complex data must go inside a key called ".complex" and the associated value must be a list (see Advanced Functionality documentation and examples). The function body can contain references to the special object L that stores the current set of simulation levels (see examples). The keys must be valid R names (see ?make.names). Any functions used within the script must be declared before set_script is called.

Value

The original simulation object with the new "simulation script" function added.

Examples

sim <- new_sim()
create_data <- function(n) { rpois(n, lambda=5) }
est_mean <- function(dat, type) {
  if (type=="M") { return(mean(dat)) }
  if (type=="V") { return(var(dat)) }
}
sim %<>% set_levels(n=c(10,100,1000), est=c("M","V"))
sim %<>% set_config(num_sim=1)
sim %<>% set_script(function() {
  dat <- create_data(L$n)
  lambda_hat <- est_mean(dat=dat, type=L$est)
  return (list("lambda_hat"=lambda_hat))
})
sim %<>% run()
sim$results %>% print()

# To return complex result data, use the special key ".complex".
sim <- new_sim()
create_data <- function(n) {
  x <- runif(n)
  y <- 3 + 2*x + rnorm(n)
  return(data.frame("x"=x, "y"=y))
}
sim %<>% set_levels("n"=c(10, 100, 1000))
sim %<>% set_config(num_sim=1)
sim %<>% set_script(function() {
  dat <- create_data(L$n)
  model <- lm(y~x, data=dat)
  return (list(
    "beta1_hat" = model$coefficients[[2]],
    ".complex" = model
  ))
})
sim %<>% run()
sim$results %>% print()
get_complex(sim, 1) %>% print()

Avi-Kenny/SimEngine documentation built on Feb. 23, 2025, 2:52 a.m.