S.PPS {TeachingSampling} | R Documentation |
Draws a probability proportional to size sample witht replacement of size $m$ from a population of size $N$
S.PPS(m,x)
m |
Sample size |
x |
Vector of auxiliary information for each unit in the population |
The selected sample is drawn acording to the cumulative total method (sequential-list procedure)
The function returns a matrix of m rows and two columns. Each element of the first column indicates the unit that was selected. Each element of the second column indicates the selection probability of this unit
Hugo Andrés Gutiérrez Rojas hugogutierrez@usantotomas.edu.co
Sarndal, C-E. and Swensson, B. and Wretman, J. (1992), Model Assisted Survey Sampling. Springer.
Guti'errez, H. A. (2009), Estrategias de muestreo: Dise~no de encuestas y estimaci'on de par'ametros.
Editorial Universidad Santo Tom'as.
############ ## Example 1 ############ # Vector U contains the label of a population of size N=5 U <- c("Yves", "Ken", "Erik", "Sharon", "Leslie") # The auxiliary information x <- c(52, 60, 75, 100, 50) # Draws a PPS sample with replacement of size m=3 res <- S.PPS(3,x) sam <- res[,1] # The selected sample is U[sam] ############ ## Example 2 ############ # Uses the Marco and Lucy data to draw a random sample according to a # PPS with replacement design data(Lucy) attach(Lucy) # The selection probability of each unit is proportional to the variable Income res<-S.PPS(400,Income) # The selected sample sam <- res[,1] # The information about the units in the sample is stored in an object called data data <- Lucy[sam,] data dim(data)