On Apr 22, 2013, at 6:21 PM, Ayyappa <ayyapp...@gmail.com> wrote: > Dear group, > > I want to generate a vector of 10 elements that always has 20% zeroes, but > with a random ordering of zeroes and ones. Can you please suggest a function > to do that in R? I tried 'sample' function but the 20% zeros was not always > guaranteed. > > Thanks for your help. > > Regards, > Ayyappa
Predefine your source vector with the fixed distribution that you desire: Vec <- c(rep(0, 2), rep(1, 8)) > Vec [1] 0 0 1 1 1 1 1 1 1 1 Then sample() from that vector: set.seed(1) > sample(Vec) [1] 1 1 1 1 0 1 1 1 1 0 > sample(Vec) [1] 1 0 1 1 1 1 1 1 0 1 > sample(Vec) [1] 1 0 1 0 1 1 1 1 1 1 > sample(Vec) [1] 1 1 1 0 1 1 1 0 1 1 Regards, Marc Schwartz ______________________________________________ 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.
