drake (version 6.2.1)

read_drake_seed: Read the pseudo-random number generator seed of the project.

Description

When a project is created with make() or drake_config(), the project's pseudo-random number generator seed is cached. Then, unless the cache is destroyed, the seeds of all the targets will deterministically depend on this one central seed. That way, reproducibility is protected, even under randomness.

Usage

read_drake_seed(path = getwd(), search = TRUE, cache = NULL,
  verbose = drake::default_verbose())

Arguments

path

Root directory of the drake project, or if search is TRUE, either the project root or a subdirectory of the project. Ignored if a cache is supplied.

search

logical. If TRUE, search parent directories to find the nearest drake cache. Otherwise, look in the current working directory only. Ignored if a cache is supplied.

cache

drake cache. See new_cache(). If supplied, path and search are ignored.

verbose

logical or numeric, control printing to the console. Use pkgconfig to set the default value of verbose for your R session: for example, pkgconfig::set_config("drake::verbose" = 2).

• 0 or FALSE: print nothing.

• 1 or TRUE: print only targets to build.

• 2: also print checks and cache info.

• 3: also print any potentially missing items.

• 4: also print imports and writes to the cache.

Value

An integer vector.

See Also

read_drake_config()

Examples

# NOT RUN {
cache <- storr::storr_environment() # Just for the examples.
my_plan <- drake_plan(
  target1 = sqrt(1234),
  target2 = sample.int(n = 12, size = 1) + target1
)
tmp <- sample.int(1) # Needed to get a .Random.seed, but not for drake.
digest::digest(.Random.seed) # Fingerprint of the current R session's seed.
make(my_plan, cache = cache) # Run the project, build the targets.
digest::digest(.Random.seed) # Your session's seed did not change.
# drake uses a hard-coded seed if you do not supply one.
read_drake_seed(cache = cache)
readd(target2, cache = cache) # Randomly-generated target data.
clean(target2, cache = cache) # Oops, I removed the data!
tmp <- sample.int(1) # Maybe the R session's seed also changed.
make(my_plan, cache = cache) # Rebuild target2.
# Same as before:
read_drake_seed(cache = cache)
readd(target2, cache = cache)
# You can also supply a seed.
# If your project already exists, it must agree with the project's
# preexisting seed (default: 0)
clean(target2, cache = cache)
make(my_plan, cache = cache, seed = 0)
read_drake_seed(cache = cache)
readd(target2, cache = cache)
# If you want to supply a different seed than 0,
# you need to destroy the cache and start over first.
clean(destroy = TRUE, cache = cache)
cache <- storr::storr_environment() # Just for the examples.
make(my_plan, cache = cache, seed = 1234)
read_drake_seed(cache = cache)
readd(target2, cache = cache)
# }