Make a random number generator repeatable
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.
repeatable(rngfunc, seed = runif(1, 0, .Machine$integer.max))
- The function that is affected by the R session's seed.
- The seed to set every time the resulting function is called.
- A repeatable version of the function that was passed in.
When called, the returned function attempts to preserve the R session's
current seed by snapshotting and restoring
rnormA <- repeatable(rnorm) rnormB <- repeatable(rnorm) rnormA(3) #  1.8285879 -0.7468041 -0.4639111 rnormA(3) #  1.8285879 -0.7468041 -0.4639111 rnormA(5) #  1.8285879 -0.7468041 -0.4639111 -1.6510126 -1.4686924 rnormB(5) #  -0.7946034 0.2568374 -0.6567597 1.2451387 -0.8375699