[R] Is it the PPS samples i needed in R?

Thomas Lumley tlumley at u.washington.edu
Tue Jan 16 19:57:13 CET 2007


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



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