Get the random number generator seed of the target currently running.
Source:R/tar_seed.R
tar_seed.RdGet the random number generator seed of the target currently running.
Arguments
- default
Integer, value to return if
tar_seed()is called on its own outside atargetspipeline. Having a default lets users run things withouttar_make(), which helps peel back layers of code and troubleshoot bugs.
Value
Integer of length 1. If invoked inside a targets pipeline,
the return value is the seed of the target currently running,
which is a deterministic function of the target name. Otherwise,
the return value is default.
Details
A target's random number generator seed
is a deterministic function of its name. In this way,
each target runs with a reproducible seed so someone else
running the same pipeline should get the same results,
and no two targets in the same pipeline share the same seed.
(Even dynamic branches have different names and thus different seeds.)
You can retrieve the seed of a completed target
with tar_meta(your_target, seed)
and run set.seed() on the result to locally
recreate the target's initial RNG state.
See also
Other utilities:
tar_active(),
tar_backoff(),
tar_call(),
tar_cancel(),
tar_definition(),
tar_envir(),
tar_group(),
tar_name(),
tar_path_script_support(),
tar_path_script(),
tar_path_store(),
tar_path_target(),
tar_path(),
tar_source(),
tar_store()
Examples
tar_seed()
#> [1] 1
tar_seed(default = 123L)
#> [1] 123
if (identical(Sys.getenv("TAR_EXAMPLES"), "true")) { # for CRAN
tar_dir({ # tar_dir() runs code from a temp dir for CRAN.
tar_script(tar_target(returns_seed, tar_seed()), ask = FALSE)
tar_make()
tar_read(returns_seed)
})
}