UPsampford {sampling} | R Documentation |
Use Sampford method to select a sample of units (unequal probabilities, without replacement, fixed sample size).
UPsampford(pik,eps=0.000005)
pik |
vector of prescribed inclusion probabilities. |
eps |
the control value, by default equal to 0.000005. |
Return a vector (0 and 1) of size N, where N is the population size. The value eps is used to control pik (pik>eps & pik < 1-eps). The sample size must be small with respect to the population size; otherwise, the selection time can be very long.
Sampford, M. (1967), On sampling without replacement with unequal probabilities of selection, Biometrika, 54:499-513.
#define the prescribed inclusion probabilities pik=c(0.2,0.7,0.8,0.5,0.4,0.4) UPsampford(pik)