<toby909 <at> gmail.com> writes: > > Gregor Gorjanc wrote: > > <toby909 <at> gmail.com> writes: > > > >>Is this a specialty with R2WinBUGS? Does it have something to do with the > >>seed value? Isnt the seed value reset everytime I restart winbugs? > > > > I always have the same seed if I start WinBUGS multiple times. > > So you get exactly the same chain, numerically, when rerunning the same > model, with the same number of iterations, everything the same.?
I just tried now with Gelman's schools example from bugs() help page. I runned the same job twice, with exactly the same initial values. Notes that WinBUGS uses always the same starting seed. I got this > schools.sim$last.values [[1]] [[1]]$theta [1] 23.700 10.060 12.760 13.090 1.693 14.390 7.599 3.961 [[1]]$mu.theta [1] 25.03 [[1]]$sigma.theta [1] 20.08 .... > schools.sim2$last.values [[1]] [[1]]$theta [1] 23.700 10.060 12.760 13.090 1.693 14.390 7.599 3.961 [[1]]$mu.theta [1] 25.03 [[1]]$sigma.theta [1] 20.08 > Wouldnt that be problematic if every researcher in the world who uses winbugs > uses the same sequence of random numbers? > > R's random numbers are different each time, because the seed is linked to the > clock in your PC. You can reset the seed if you want. Having the same seed is also nice for repeatability. Gregor ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.