Demonstration of the systematic sampling

Yihui Xie & Lijia Yu 2017-04-04

The whole sample frame is denoted by a matrix (nrow * ncol) in the plane, and the sample points with equal intervals are drawn out according to a random starting point. The points being sampled are marked by red circles.

ani.options(nmax = 50)
par(mar = rep(1, 4), lwd = 2)

plot of chunk demo-a