Systematic Sampling
Draws a Systematic sample of size $n$ from a population of size $N$
S.SY(N, a)
N |
Population size |
a |
Number of groups dividing the population |
The selected sample is drawn according to a random start.
The function returns a vector of size n. Each element of this vector indicates the unit that was selected.
Hugo Andres Gutierrez Rojas hagutierrezro@gmail.com. The author acknowledges to Kristina Stodolova Kristyna.Stodolova@seznam.cz for valuable suggestions.
Madow, L.H. and Madow, W.G. (1944), On the theory of systematic sampling. Annals of Mathematical Statistics. 15, 1-24.
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.
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## Example 1
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# Vector U contains the label of a population of size N=5
U <- c("Yves", "Ken", "Erik", "Sharon", "Leslie")
# The population of size N=5 is divided in a=2 groups
# Draws a Systematic sample.
sam <- S.SY(5,2)
sam
# The selected sample is
U[sam]
# There are only two possible samples
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## Example 2
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# Uses the Lucy data to draw a Systematic sample
data(Lucy)
attach(Lucy)
N <- dim(Lucy)[1]
# The population is divided in 6 groups
# The selected sample
sam <- S.SY(N,6)
# The information about the units in the sample is stored in an object called data
data <- Lucy[sam,]
data
dim(data)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.