Shiny by RStudio

Make a random number generator repeatable

repeatable(rngfunc, seed = stats::runif(1, 0, .Machine$integer.max))

Arguments

rngfunc The function that is affected by the R session's seed.
seed The seed to set every time the resulting function is called.

Value

A repeatable version of the function that was passed in.

Description

Given a function that generates random data, returns a wrapped version of that function that always uses the same seed when called. The seed to use can be passed in explicitly if desired; otherwise, a random number is used.

Note

When called, the returned function attempts to preserve the R session's current seed by snapshotting and restoring .Random.seed.

Examples

rnormA <- repeatable(rnorm) rnormB <- repeatable(rnorm) rnormA(3) # [1] 1.8285879 -0.7468041 -0.4639111
[1] 1.5308819 0.9697510 0.5213101
rnormA(3) # [1] 1.8285879 -0.7468041 -0.4639111
[1] 1.5308819 0.9697510 0.5213101
rnormA(5) # [1] 1.8285879 -0.7468041 -0.4639111 -1.6510126 -1.4686924
[1] 1.5308819 0.9697510 0.5213101 1.0563204 0.1629233
rnormB(5) # [1] -0.7946034 0.2568374 -0.6567597 1.2451387 -0.8375699
[1] 0.2644419 0.2545899 -0.1941631 0.6304822 -0.7231721