On Fri, 12 Jan 2007, zhijie zhang wrote: > Dear friends, > I want to do a unequal probability sampling, that is, Probability > Proportionate to size, Is it right for the following programs? > Say my original dataset is: > > ID Population > 1 100 > 2 200 > 3 300 > IF the population is large ,then the corresponding ID has the large > Probability to be selected. > > sample(A$ID, size=2, replace = FALSE, prob = A$population) > #suppose the dataset name is A. > Is it the PPS samples i needed ?
No, this does not give PPS samples for size>1. The "pps" and "sampling" packages have code for PPS samples. -thomas ______________________________________________ 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.