On 2017-02-07 15:59, Martin Maechler wrote:
Henric Winell <nilsson.hen...@gmail.com> on Tue, 7 Feb 2017 13:37:42 +0100 writes:> Hi, On 2017-02-07 13:12, Benjamin Tyner wrote: >> Hello >> >> When loading a package, I'm wondering if it's frowned >> upon for the package to alter the state of the random >> number generator? I guess not, since the parallel package >> does it? > Surprisingly it is not frowned upon, but it *is* a > nuisance. I brought it up a couple of years ago > http://r.789695.n4.nabble.com/parallel-package-changes-Random-seed-td4686321.html > along with a patch, but was told off... >> >> > set.seed(6860) > old.seed <- .GlobalEnv$.Random.seed > >> library(parallel) > new.seed <- .GlobalEnv$.Random.seed > >> identical(old.seed, new.seed) [1] FALSE >> >> I ask because, I found myself writing a custom wrapper >> around library() to restore the original RNG state, in >> order to increase reproducibility. But now wondering if >> others would welcome such a feature to be added to base >> R? Either something very general like >> >> preserveRNGstate(library(parallel)) >> >> or perhaps an specific enhancement to library itself? > I would very much welcome a change, but in the light of > things it doesn't seem likely. > Henric Winell Sometimes things change ... and not always for the worse. I've found a version of your original patch idea which is very efficient nice (in my eyes) and still leaves system.time(loadNamespace("parallel")) to round to 0, i.e. needing less than 1 ms. --> in R-devel svn rev 72136
Many thanks for this, Martin! Henric
Martin
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