inclusionprobabilities(a,n)

############
## Example 1
############
# a vector of positive numbers
a=1:20
# computation of the inclusion probabilities for a sample size n=12
pik=inclusionprobabilities(a,12)
pik
############
## Example 2
############
# Computation of the inclusion probabilities proportional to the number 
# of inhabitants in each municipality of the Belgian database.
data(belgianmunicipalities)
pik=inclusionprobabilities(belgianmunicipalities$Tot04,200)
# the first-order inclusion probabilities for each municipality
data.frame(pik=pik,name=belgianmunicipalities$Commune)
# the inclusion probability sum is equal to the sample size
sum(pik)