BalancedSampling (version 1.6.3)

lcubeflightphase: Flight phase for the local cube method

Description

Flight phase for the local cube method. To have a fixed sample size, include the inclusion probabilities as a balancing variable in Xbal and make sure the inclusion probabilities sum to a positive integer. This is a simplified (optimized for speed) implementation of the flight phase of the local cube method (doubly balanced sampling). Euclidean distance is used in the Xspread space.

Usage

lcubeflightphase(prob,Xspread,Xbal)

Value

Returns a vector of length N with new probabilities, where at most r are non-integer.

Arguments

prob

vector of length N with inclusion probabilities

Xspread

matrix of (standardized) auxiliary variables of N rows and q columns

Xbal

matrix of balancing auxiliary variables of N rows and r columns

References

Grafström, A. and Tillé, Y. (2013). Doubly balanced spatial sampling with spreading and restitution of auxiliary totals. Environmetrics, 24(2), 120-131.

Examples

if (FALSE) {
# Example 1
# Select sample
set.seed(12345);
N = 100; # population size
n = 10; # sample size
p = rep(n/N,N); # inclusion probabilities
X = cbind(runif(N),runif(N)); # matrix of auxiliary variables
pflight = lcubeflightphase(p,X,cbind(p,X)); 
# check balance
colSums(X)
colSums(X/p*pflight)

}