1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
|
## Evaluates an R expression while preventing any changes to .Random.seed
with_stealth_rng <- function(expr, substitute = TRUE, envir = parent.frame(), ...) {
if (substitute) expr <- substitute(expr)
## Record the original RNG state
oseed <- .GlobalEnv$.Random.seed
on.exit({
if (is.null(oseed)) {
if (exists(".Random.seed", envir = .GlobalEnv, inherits = FALSE)) {
rm(list = ".Random.seed", envir = .GlobalEnv, inherits = FALSE)
}
} else {
.GlobalEnv$.Random.seed <- oseed
}
})
## Evaluate the R expression with "random" RNG state
if (!is.null(oseed)) {
rm(list = ".Random.seed", envir = .GlobalEnv, inherits = FALSE)
}
eval(expr, envir = envir, enclos = baseenv())
}
|
