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.
sample.system(
nrow = 10,
ncol = 10,
size = 15,
p.col = c("blue", "red"),
p.cex = c(1, 3)
)None (invisible NULL).
the desired number of rows of the sample frame.
the desired number of columns of the sample frame.
the sample size.
different colors / magnification rate to annotate the population and the sample
Yihui Xie
Examples at https://yihui.org/animation/example/sample-system/
sample, sample.simple,
sample.cluster, sample.ratio,
sample.strat