Set a seed local to a call — local

When used inside a call, local_seed() first records the existing seed then transiently sets a specific one. When the call exits, the recorded seed is set again, so that the transient seed setting leaves no effects.
Based on discussion from https://support.bioconductor.org/p/110439/

Usage

local_seed(seed)

Arguments

seed: seed value to set

Value

set up seed passed to environment

Examples

f <- function() {
    local_seed(1234)
    r_val <- rnorm(1)
    return(r_val)
}

rnorm(1) # make sure a seed exists (not needed but handy for this example)
#> [1] 0.2553171

seed1 <- .Random.seed
x <- f()
seed2 <- .Random.seed
y <- rnorm(1)
seed3 <- .Random.seed
z <- f()

identical(seed1, seed2)
#> [1] TRUE
!identical(seed1, seed3)
#> [1] TRUE

identical(x, z)
#> [1] TRUE
!identical(x, y)
#> [1] TRUE