[R] random number generator?

Peter Dalgaard BSA p.dalgaard at biostat.ku.dk
Wed Jan 29 21:41:03 CET 2003

ripley at stats.ox.ac.uk writes:

> That's what RNGkind and set.seed do, and have done for a long time.
> The information is also stored in .Random.seed, but few users would record 
> that (and it does not exist until the first RNG is used).

.. but if you don't set the seed, you shouldn't expect reproducible
behaviour anyway:

[pd at rasch pd]$ echo "rnorm(2)" | R --vanilla --slave
[1] 2.0281025 0.8735026

[pd at rasch pd]$ echo "rnorm(2)" | R --vanilla --slave
[1] -1.2695122 -0.0448524

I mean, if the prototypical answer to people complaining "I'm not
getting the same results" is simply to ask them to put an 
RNGkind("Marsaglia-Multicarry","Kinderman-Ramage") next to their first
set.seed(), how troublesome could it be?
   O__  ---- Peter Dalgaard             Blegdamsvej 3  
  c/ /'_ --- Dept. of Biostatistics     2200 Cph. N   
 (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)             FAX: (+45) 35327907

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