On Tue, 30 Oct 2007, Azam, Mehtabul wrote:
>>> Hi,
> I am trying to draw a random sample from an household survey with
> sample weight. Is there any function in R or Splus which allows this.
>
It depends on exactly what you want.
The sample() function will draw unequal probability samples with
replacement.
sample() will also draw samples without replacement, but (as documented)
it uses sequential sampling and so does not actually generate
probabilities proportional to the specified weights for sample sizes
greater than 1.
The error in sequential sampling is pretty small, but it has attracted a
lot of creativity in the survey literature (probably more than it
deserves). The 'sampling' package implements several algorithms for
drawing unequal probability samples without replacement that really are
proportional to the specified weights where this is achievable.
-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.
