Run a simulator over prior draws

Draws n parameter vectors from the prior and pushes them through the simulator. The simulator is called on chunks of rows rather than on the whole matrix at once, which is what lets the run report progress and, under a future plan, spread the chunks across workers. See nsbi_parallel and nsbi_progress.

Usage

simulate_for_sbi(
  simulator,
  prior,
  n,
  seed = NULL,
  verbose = FALSE,
  chunk_size = NULL
)

Arguments

simulator

A function mapping an n x dim matrix of parameters to an n x d matrix of simulated data. Ignored if theta and x are given. Column names on its output (e.g. via colnames(out) <- c("cases_wk1", ...)) become the outcome names used in plots.

prior

An nsbi_prior (see prior_uniform(), prior_normal()).

n

Number of simulations.

seed

Optional integer seed for reproducibility.

verbose

Print training progress.

chunk_size

Rows of theta per simulator call. NULL (default) splits the run into about 64 chunks. Chunks are the unit of work sent to future workers and the unit of progress reporting; see nsbi_parallel.

Value

A list with theta (n x dim) and x (n x d) matrices.

Examples

prior <- prior_uniform(c(-1, -1), c(1, 1))
sims <- simulate_for_sbi(function(theta) theta^2, prior, n = 100)
str(sims)
#> List of 2
#>  $ theta: num [1:100, 1:2] -0.0435 0.4745 -0.8025 -0.3234 0.3867 ...
#>  $ x    : num [1:100, 1:2] 0.00189 0.22512 0.64396 0.10456 0.14956 ...