Launch a drake function in a fresh new R process

The r_*() functions, such as r_make(), enhance reproducibility by launching a drake function in a separate R process.

Usage

r_make(source = NULL, r_fn = NULL, r_args = list())

r_drake_build(
  target,
  character_only = FALSE,
  ...,
  source = NULL,
  r_fn = NULL,
  r_args = list()
)

r_outdated(..., source = NULL, r_fn = NULL, r_args = list())

r_recoverable(..., source = NULL, r_fn = NULL, r_args = list())

r_missed(..., source = NULL, r_fn = NULL, r_args = list())

r_deps_target(
  target,
  character_only = FALSE,
  ...,
  source = NULL,
  r_fn = NULL,
  r_args = list()
)

r_drake_graph_info(..., source = NULL, r_fn = NULL, r_args = list())

r_vis_drake_graph(..., source = NULL, r_fn = NULL, r_args = list())

r_sankey_drake_graph(..., source = NULL, r_fn = NULL, r_args = list())

r_drake_ggraph(..., source = NULL, r_fn = NULL, r_args = list())

r_text_drake_graph(..., source = NULL, r_fn = NULL, r_args = list())

r_predict_runtime(..., source = NULL, r_fn = NULL, r_args = list())

r_predict_workers(..., source = NULL, r_fn = NULL, r_args = list())

Arguments

source

Path to an R script file that loads packages, functions, etc. and returns a drake_config() object. There are 3 ways to set this path.

1. Pass an explicit file path.

2. Call options(drake_source = "path_to_your_script.R").

3. Just create a file called "_drake.R" in your working directory and supply nothing to source.

r_fn

A callr function such as callr::r or callr::r_bg. Example: r_make(r_fn = callr::r).

r_args

List of arguments to r_fn, not including func or args. Example: r_make(r_fn = callr::r_bg, r_args = list(stdout = "stdout.log")).

target

Name of the target.

character_only

Logical, whether name should be treated as a character or a symbol (just like character.only in library()).

...

Arguments to the inner function. For example, if you want to call r_vis_drake_graph(), the inner function is vis_drake_graph(), and selfcontained is an example argument you could supply to the ellipsis.

Details

drake searches your environment to detect dependencies, so functions like make(), outdated(), etc. are designed to run in fresh clean R sessions. Wrappers r_make(), r_outdated(), etc. run reproducibly even if your current R session is old and stale.

r_outdated() runs the four steps below. r_make() etc. are similar.

1. Launch a new callr::r() session.

2. In that fresh session, run the R script from the source argument. This script loads packages, functions, global options, etc. and calls drake_config() at the very end. drake_config() is the preprocessing step of make(), and it accepts all the same arguments as make() (e.g. plan and targets).

3. In that same session, run outdated() with the config argument from step 2.

4. Return the result back to main process (e.g. your interactive R session).

Recovery

make(recover = TRUE, recoverable = TRUE) powers automated data recovery. The default of recover is FALSE because targets recovered from the distant past may have been generated with earlier versions of R and earlier package environments that no longer exist.

How it works: if recover is TRUE, drake tries to salvage old target values from the cache instead of running commands from the plan. A target is recoverable if

1. There is an old value somewhere in the cache that shares the command, dependencies, etc. of the target about to be built.

2. The old value was generated with make(recoverable = TRUE).

If both conditions are met, drake will

1. Assign the most recently-generated admissible data to the target, and

2. skip the target's command.

See also

make()

Examples

if (FALSE) { # \dontrun{
isolate_example("quarantine side effects", {
if (requireNamespace("knitr", quietly = TRUE)) {
writeLines(
  c(
    "library(drake)",
    "load_mtcars_example()",
    "drake_config(my_plan, targets = c(\"small\", \"large\"))"
  ),
  "_drake.R" # default value of the `source` argument
)
cat(readLines("_drake.R"), sep = "\n")
r_outdated()
r_make()
r_outdated()
}
})
} # }