RNG usability
On Wed, 23 Feb 2000, Paul Gilbert wrote:
It does not necessarily save the state of other generators, and in particular does not save the state of the Box-Muller normal generator.
I thought Box-Muller just transformations uniform numbers? Does its state just refer to whether an even or odd number of numbers have been produced, and in the later case keep the last one for using the next time?
Yes.
If you want to reproduce work later, call `set.seed' rather than set
`.Random.seed'. But then I'm back to the original problem (which fortunately does not seem to be a problem for the uniform generator): Using B-M for rnorm I can't query the state at any given time and then reliably reset to that state?
Yes. So use a more reliable option for norm_rand.
Brian D. Ripley, ripley@stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272860 (secr) Oxford OX1 3TG, UK Fax: +44 1865 272595 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-devel mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-devel-request@stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._