S.BE {TeachingSampling}

Bernoulli Sampling Without Replacement

Description

Draws a Bernoulli sample without replacement of expected size $n$ from a population of size $N$

Usage

S.BE(N, prob)

Arguments

N

Population size

prob

Inclusion probability for each unit in the population

Details

The selected sample is drawn according to a sequential procedure algorithm based on an uniform distribution. The Bernoulli sampling design is not a fixed sample size one.

Value

The function returns a vector of size N. Each element of this vector indicates if the unit was selected. Then, if the value of this vector for unit k is zero, the unit k was not selected in the sample; otherwise, the unit was selected in the sample.

Author(s)

Hugo Andres Gutierrez Rojas [e-mail]

References

Sarndal, C-E. and Swensson, B. and Wretman, J. (1992), Model Assisted Survey Sampling. Springer.
Gutierrez, H. A. (2009), Estrategias de muestreo: Diseno de encuestas y estimacion de parametros. Editorial Universidad Santo Tomas.
Tille, Y. (2006), Sampling Algorithms. Springer.

See Also

E.BE

Examples

############
## Example 1
############
# Vector U contains the label of a population of size N=5
U <- c("Yves", "Ken", "Erik", "Sharon", "Leslie")
# Draws a Bernoulli sample without replacement of expected size n=3
# The inlusion probability is 0.6 for each unit in the population
sam <- S.BE(5,0.6)
sam
# The selected sample is
U[sam]

############
## Example 2
############
# Uses the Lucy data to draw a Bernoulli sample

data(Lucy)
attach(Lucy)
N <- dim(Lucy)[1]
# The population size is 2396. If the expected sample size is 400
# then, the inclusion probability must be 400/2396=0.1669
sam <- S.BE(N,0.01669)
# The information about the units in the sample is stored in an object called data
data <- Lucy[sam,]
data
dim(data)