rfsrc.RNGversion: Select the RNG Version for New Forests

In randomForestSRC: Fast Unified Random Forests for Survival, Regression, and Classification (RF-SRC)

Select the RNG Version for New Forests

Description

Select or query the random number generator (RNG) seed initialization protocol used to grow new forests with rfsrc. Most users do not need to call this function. New forests use the recommended wide generator by default. Set the RNG version only to reproduce or test legacy behavior.

Usage

rfsrc.RNGversion(version)

Arguments

version

A character string: "3.2.3" selects the legacy protocol and "3.10.0" selects the wide protocol. Omit this argument to query the current selection. Supply NULL to remove the override and restore the default, "3.10.0". Other values are rejected.

Details

Use of the legacy generator is not recommended for new analyses. Select "3.2.3" only when reproducing or testing legacy behavior; otherwise use the default, "3.10.0".

The selection is stored in the R session option rf.rng.version. When that option is unset, new forests use "3.10.0". Functions that grow forests through rfsrc() in the same R session inherit this setting. Independent R sessions, including separate worker or test processes, must set their own selection.

Each newly grown forest records its selection in fit$forest$rng.version. Restoration, prediction, partial dependence, and variable importance use the saved forest's protocol, regardless of the current session setting. Forests without RNG metadata use the legacy protocol, "3.2.3".

These identifiers select the package's seed-head protocol. Selecting a protocol does not set a seed, change R's RNGkind, or alter .Random.seed. Use the seed argument to rfsrc() or set.seed to control the seed.

The legacy identifier marks the earliest supported RNG compatibility baseline, including variable importance. Selecting it does not restore other historical package defaults or guarantee identical results after unrelated algorithm changes.

Value

With no argument, the current effective RNG version as a character string. When setting or resetting the selection, the previous stored option is returned invisibly. This is NULL when no override was set, allowing the previous setting to be restored with another call to rfsrc.RNGversion().

Author(s)

Hemant Ishwaran and Udaya B. Kogalur

See Also

rfsrc, RNGversion, set.seed

Examples

## Only for reproducing or testing legacy behavior.
local({
  previous <- rfsrc.RNGversion("3.2.3")
  on.exit(rfsrc.RNGversion(previous))

  fit <- rfsrc(Sepal.Length ~ ., iris, ntree = 25, seed = -1234)
  print(fit$forest$rng.version)

  ## Return to the recommended wide generator for subsequent fits.
  rfsrc.RNGversion("3.10.0")
  print(rfsrc.RNGversion())

  ## The existing forest keeps its original protocol.
  print(fit$forest$rng.version)

  ## Remove the session override.
  rfsrc.RNGversion(NULL)
  print(rfsrc.RNGversion())
})

randomForestSRC documentation built on Nov. 1, 2026, 5:07 p.m.