animation (version 1.1-4)

sample.simple: Demonstration for simple random sampling without replacement...

Description

Demonstration for simple random sampling without replacement The whole sample frame is denoted by a matrix (nrow * ncol) in the plane just for convenience, and the points being sampled are marked out (by red circles by default). Each member of the population has an equal and known chance of being selected.

Usage

sample.simple(nrow=10, ncol=10, size=15, p.col=c("blue", "red"),
    p.cex=c(1, 3))

Arguments

nrow

the desired number of rows of the sample frame.

ncol

the desired number of columns of the sample frame.

size

the sample size.

p.col,p.cex

different colors /magnification rate to annotate the population and the sample

Value

• None (invisible `NULL').

References

Cochran, W G (1977) Sampling Techniques, Wiley, ISBN 0-471-16240-X http://animation.yihui.name/samp:srswr

See Also

sample, sample.ratio, sample.cluster, sample.strat, sample.system

Examples

oopt = ani.options(interval = 1, nmax = 30)
op = par(mar = rep(1, 4))
sample.simple()
par(op)
# HTML animation page
ani.options(ani.height = 350, ani.width = 500, nmax = 30, interval = 1,
title = "Demonstration of the simple random sampling without replacement",
description = "Each member of the population has an equal and known chance
of being selected.")
ani.start()
par(mar = rep(1, 4), lwd = 2)
sample.simple()
ani.stop()
ani.options(oopt)