sampling (version 0.45)

balancedstratification: Balanced stratification

Description

Selects a stratified balanced sample (a vector of 0 and 1). Firstly, the flight phase is applied in each stratum. Secondly, the strata are aggregated and the flight phase is applied on the whole population. Finally, the landing phase is applied on the whole population.

Usage

balancedstratification(X,strat,pik,comment=TRUE,method=1)

Arguments

X

matrix of auxiliary variables on which the sample must be balanced.

strat

vector of integers that specifies the stratification.

pik

vector of inclusion probabilities.

comment

a comment is written during the execution if comment is equal to TRUE.

method

the used method in the function samplecube.

encoding

latin1

References

Till�, Y. (2006), Sampling Algorithms, Springer. Chauvet, G. and Till�, Y. (2006). A fast algorithm of balanced sampling. to appear in Computational Statistics. Chauvet, G. and Till�, Y. (2005). New SAS macros for balanced sampling. In INSEE, editor, Journ�es de M�thodologie Statistique, Paris. Deville, J.-C. and Till�, Y. (2004). Efficient balanced sampling: the cube method. Biometrika, 91, 893-912. Deville, J.-C. and Till�, Y. (2005). Variance approximation under balanced sampling. Journal of Statistical Planning and Inference, 128/2:411--425.

See Also

samplecube, fastflightcube, landingcube

Examples

############
## Example 1
############
# variable of stratification (3 strata)
strat=c(1,1,1,1,1,2,2,2,2,2,3,3,3,3,3)
# matrix of balancing variables
X=cbind(c(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15))
# Vector of inclusion probabilities.
# The sample has its size equal to 9.
pik=rep(3/5,times=15)
# Selection of a stratified sample
s=balancedstratification(X,strat,pik,comment=TRUE)
# The sample is
(1:length(pik))[s==1]
############
## Example 2
############
data(MU284)
X=cbind(MU284$P75,MU284$CS82,MU284$SS82,MU284$S82,MU284$ME84)
strat=MU284$REG
pik=inclusionprobabilities(MU284$P75,80)
s=balancedstratification(X,strat,pik,TRUE)
############
## Example 3
############
data(swissmunicipalities)
swiss=swissmunicipalities
X=cbind(swiss$HApoly,
        swiss$Surfacesbois,
        swiss$P00BMTOT,
        swiss$P00BWTOT,
        swiss$POPTOT,
        swiss$Pop020,
        swiss$Pop2040,
        swiss$Pop4065,
        swiss$Pop65P,
        swiss$H00PTOT )
pik=inclusionprobabilities(swiss$POPTOT,400)
sample=balancedstratification(X,swiss$REG,pik,comment=TRUE)
#the sample is
as.character(swiss$Nom[sample==1])