UPtillepi2 {sampling} | R Documentation |
Compute the joint inclusion probabilities for Tillé sampling.
UPtillepi2(pik,eps=1e-6)
pik |
vector of first order inclusion probabilities. |
eps |
the control value, by default equal to 1e-6. |
Return a NxN matrix with the first order inclusion probability for each unit k in the population on the first diagonal and with the joint inclusion probability of units k and l in position (k,l) in the matrix, where $kneq l$ (N is the population size). The value eps is used to control pik (pik>eps & pik < 1-eps).
Tillé, Y. (1996), An elimination procedure of unequal probability sampling without replacement, Biometrika, 83:238-241.
#define the prescribed inclusion probabilities pik=c(0.2,0.7,0.8,0.5,0.4,0.4) s=UPtillepi2(pik) #the sample is (1:length(pik))[s==1]