# S.SY: Systematic Sampling In damarals/TeachingSampling: Selection of Samples and Parameter Estimation in Finite Population

## Description

Draws a Systematic sample of size \$n\$ from a population of size \$N\$

## Usage

 `1` ```S.SY(N, a) ```

## Arguments

 `N` Population size `a` Number of groups dividing the population

## Details

The selected sample is drawn according to a random start.

## Value

The function returns a vector of size n. Each element of this vector indicates the unit that was selected.

## Author(s)

Hugo Andres Gutierrez Rojas hugogutierrez@usantotomas.edu.co. The author acknowledges to Kristina Stodolova Kristyna.Stodolova@seznam.cz for valuable suggestions.

## References

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.

`E.SY`
 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28``` ```############ ## Example 1 ############ # 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 ############ ## Example 2 ############ # 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) ```