Thank you, Rui, but I have the feeling that in this way you are drawing uniformly *ordered* samples, and you get a bias if you consider them to be unordered.
Best, Giovanni ________________________________________ From: Rui Barradas [[email protected]] Sent: Wednesday, September 17, 2014 13:49 To: Giovanni Petris; [email protected] Subject: Re: [R] Generating unordered, with replacement, samples Hello, Try function ?sample. Something like, if 'x' is a vector of size n, sample(x, k, replace = TRUE) If you want indices into 'x', try instead sample(n, k, replace = TRUE) Hope this helps, Rui Barradas Em 17-09-2014 19:25, Giovanni Petris escreveu: > > Hello, > > I am trying to interface in my teaching some elementary probability with > Monte Carlo ideas. In sampling from a finite population, the number of > distinct samples of size 'k' from a population of size 'n' , when individuals > are selected with replacement and the selection order does not matter, is > choose(n + k -1, k). Does anyone have a suggestion about how to simulate > (uniformly!) one of these possible samples? In a Monte Carlo framework I > would like to do it repeatedly, so efficiency is of some relevance. > > Thank you in advance! > > Best, > Giovanni > > > > Giovanni Petris > Associate Professor > Department of Mathematical Sciences > University of Arkansas - Fayetteville, AR 72701 > Ph: (479) 575-6324, 575-8630 (fax) > http://definetti.uark.edu/~gpetris/ > > > ______________________________________________ > [email protected] 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. > ______________________________________________ [email protected] 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.
