Postratification
Poststratification using several criteria.
poststrata(data, postnames = NULL)
data |
data frame or data matrix; its number of rows is n, the sample size. |
postnames |
vector of poststratification variables. |
The function |
produces an object, which contains the following information: |
data |
the final data frame with a new column ('poststratum') containg the unit poststratum. |
npost |
the number of poststrata. |
# Example from An and Watts (New SAS procedures for Analysis of Sample Survey Data)
# generates artificial data (a 235X3 matrix with 3 columns: state, region, income).
# the variable "state" has 2 categories ('nc' and 'sc').
# the variable "region" has 3 categories (1, 2 and 3).
# the income variable is randomly generated
data=rbind(matrix(rep("nc",165),165,1,byrow=TRUE),matrix(rep("sc",70),70,1,byrow=TRUE))
data=cbind.data.frame(data,c(rep(1,100), rep(2,50), rep(3,15), rep(1,30),rep(2,40)),
1000*runif(235))
names(data)=c("state","region","income")
# computes the population stratum sizes
table(data$region,data$state)
# not run
# nc sc
# 1 100 30
# 2 50 40
# 3 15 0
# postratification using two criteria: state and region
poststrata(data,postnames=c("state","region"))Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.