R random number generator
On Wed, 28 Apr 1999, Mai Zhou wrote:
R 0.64 on windows NT 4.0
Um: there is no such version. R 0.64.0?
Sometimes I got an error message by doing this
.Random.seed <- c(1, 1:2) .Random.seed
[1] 1 1 2
runif(5)
Warning: Wrong length .Random.seed; forgot initial RNGkind? set to Wichmann-Hill[1] 0.02253721 0.84832584 ........
That is a logical error. Because Martin M put backwards compatibility code in, all initial .Random.seed of length 3 are taken to be mistakes for the earlier specification of the Wichmann-Hill generator. Although the help page does not say so, both "Marsaglia-Multicarry" and "Super-Duper" need seeds of length 3. However, this does not apply if you have already successfully set the RNG kind. So the work-around is
RNGkind("Marsaglia-Multicarry") # or .Random.seed <- 1
.Random.seed <- c(1, 1:2)
runif(5)
[1] 0.5641106 0.2932388 0.6696743 0.9174765 0.1490988 The rest of the examples I think come in the same way: it depends on what has been set before. I'll look into it, but I don't think anyone anticipated that one would swap generators during a session. [Martin: I am about to commit some fixes.]
Brian D. Ripley, ripley at 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-help 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-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._