RNGseq: Generate Sequence of Random Streams

In rngtools: Utility functions for working with Random Number Generators

Description

Create a given number of seeds for L'Ecuyer's RNG, that can be used to seed parallel computation, making them fully reproducible.

RNGseq_seed generates the – next – random seed used as the first seed in the sequence generated by RNGseq.

Usage

  RNGseq(n, seed = NULL, ..., simplify = TRUE, version = 2)

  RNGseq_seed(seed = NULL, normal.kind = NULL,
    verbose = FALSE, version = 2)

Arguments

n	Number of streams to be created
seed	seed specification used to initialise the set of streams using RNGseq_seed.
simplify	a logical that specifies if sequences of length 1 should be unlisted and returned as a single vector.
...	extra arguments passed to RNGseq_seed.
normal.kind	Type of Normal random generator. See RNG.
verbose	logical to toggle verbose messages
version	version of the function to use, to reproduce old behaviours. Version 1 had a bug which made the generated stream sequences share most of their seeds (!), as well as being not equivalent to calling set.seed(seed); RNGseq_seed(NULL). Version 2 fixes this bug.

Details

This ensures complete reproducibility of the set of run. The streams are created using L'Ecuyer's RNG, implemented in R core since version 2.14.0 under the name "L'Ecuyer-CMRG" (see RNG).

Generating a sequence without specifying a seed uses a single draw of the current RNG. The generation of a sequence using seed (a single or 6-length numeric) a should not affect the current RNG state.

Value

a list of integer vectors (or a single integer vector if n=1 and unlist=TRUE).

a 7-length numeric vector.

See Also

RNGseq

Examples

RNGseq(3)
RNGseq(3)
RNGseq(3, seed=123)
# or identically
set.seed(123)
identical(RNGseq(3), RNGseq(3, seed=123))


RNGseq(3, seed=1:6, verbose=TRUE)
# select Normal kind
RNGseq(3, seed=123, normal.kind="Ahrens")
## generate a seed for RNGseq
# random
RNGseq_seed()
RNGseq_seed()
RNGseq_seed(NULL)
# fixed
RNGseq_seed(1)
RNGseq_seed(1:6)

# `RNGseq_seed(1)` is identical to
set.seed(1)
s <- RNGseq_seed()
identical(s, RNGseq_seed(1))

rngtools documentation built on May 2, 2019, 5 p.m.