flightphase {BalancedSampling} | R Documentation |
This is a fast implementation of the flight phase of the 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.
flightphase(prob,Xbal)
prob |
vector of length N with inclusion probabilities |
Xbal |
matrix of balancing auxiliary variables of N rows and q columns |
Returns a vector of length N with new probabilities, where at most q are non-integer.
Deville, J. C. and TillĂ©, Y. (2004). Efficient balanced sampling: the cube method. Biometrika, 91(4), 893-912.
Chauvet, G. and TillĂ©, Y. (2006). A fast algorithm for balanced sampling. Computational Statistics, 21(1), 53-62.
## Not run: # Example 1 # Select sample and check balance set.seed(12345); N = 100; # population size n = 10; # sample size p = rep(n/N,N); # inclusion probabilities X = cbind(p,runif(N),runif(N)); # matrix of auxiliary variables pflight = flightphase(p,X); # check balance after flight colSums(X) colSums(X/p*pflight) # select final sample as indicators indicators = landingphase(p,pflight,X); # check final balance colSums(X) colSums(X/p*indicators) # final sample as indexes s = (1:N)[indicators==1]; ## End(Not run)