You have to set the same seed before each random number generation! You did not do this.
Bert Gunter Genentech Nonclinical Biostatistics (650) 467-7374 "Data is not information. Information is not knowledge. And knowledge is certainly not wisdom." H. Gilbert Welch On Wed, Jan 1, 2014 at 2:12 PM, Chee Chen <chee.c...@yahoo.com> wrote: > Dear All, > > I would like to ask for your help on "reproducibility of random sampling with > replacement". For example, one re-samples the rows with replacement of a > residual matrix and uses the new residual matrix thus obtained to produce a > statistic ; repeat this for a certain number of times. > > My questions: will the above produce ever be reproducible by setting a seed? > Namely, Given the same residual matrix, Ted applies the above process and so > does Jack, will they get the same results by setting a seed? > > My attempt: setting seed does not freeze the command "sample" from getting > different samples, as from the codes: > ==== > x= 1:20 > S = matrix(0,5,20) > for (i in 1:5) { > S[i,] = sample(x, replace=FALSE) > } > > set.seed(123) > > T = matrix(0,5,20) > for (i in 1:5) { > T[i,] = sample(x, replace=FALSE) > } > sum(S==T) > === > > I would appreciate any comments and/or suggestions on this. > Regards, > Chee > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org 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. ______________________________________________ R-help@r-project.org 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.