sampling (version 2.10)

UPpivotal: Pivotal sampling

Description

Selects an unequal probability sample using the pivotal method (unequal probabilities, without replacement, fixed sample size).

Usage

UPpivotal(pik,eps=1e-6)

Value

Returns a vector (with elements 0 and 1) of size N, the population size. Each element k of this vector indicates the status of unit k (1, unit k is selected in the sample; 0, otherwise). The value eps is used to control pik (pik>eps & pik < 1-eps).

Arguments

pik

vector of the inclusion probabilities.

eps

control value, by default equal to 1e-6.

References

Deville, J.-C. and Tillé, Y. (1998), Unequal probability sampling without replacement through a splitting method, Biometrika, 85:89-101.
Chauvet, G. and Tillé, Y. (2006). A fast algorithm of balanced sampling. to appear in Computational Statistics.
Tillé, Y. (2006), Sampling Algorithms, Springer.

See Also

UPrandompivotal

Examples

#define the prescribed inclusion probabilities
pik=c(0.2,0.7,0.8,0.5,0.4,0.4)
#select a sample
s=UPpivotal(pik)
#the sample is
which(s==1)