On Thu, 7 Feb 2008, Tim Hesterberg wrote: > Thomas Lumley wrote: >> Now, it might be useful to add another replace=FALSE sampler to sample(), >> such as the newish Conditional Poisson Sampler based on the work of >> S.X.Chen. This does give correct marginal probabilities of inclusion, and >> the pairwise joint probabilities are not too hard to compute. > > That could be interesting. The pairwise joint probabilities are > important in some applications. Are all the pairwise joint > probabilities nonzero (when size*prob allows that)? >
Yes. > Note that any algorithm for sampling without replacement can be > extended to sampling with minimal replacement, by first drawing > observations using the integer part of (size*prob), then reducing size > and adjusting prob prior to random drawing. Certainly -- the difficult part is sampling without replacement. -thomas Thomas Lumley Assoc. Professor, Biostatistics [EMAIL PROTECTED] University of Washington, Seattle ______________________________________________ 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.