Simulates the quincunx with ``balls'' (beans) falling through several layers
(denoted by triangles) and the distribution of the final locations at which
the balls hit is denoted by a histogram; quincunx() is shows single
layer, and quincunx2() is a two-stage version of the quincunx.
quincunx(
balls = 200,
layers = 15,
pch.layers = 2,
pch.balls = 19,
col.balls = sample(colors(), balls, TRUE),
cex.balls = 2
)quincunx2(
balls = 200,
layers = 15,
pch.layers = 2,
pch.balls = 19,
col.balls = sample(colors(), balls, TRUE),
cex.balls = 2
)
number of balls
number of layers
point character of layers; triangles (pch = 2) are
recommended
point character, colors and magnification of balls
A named vector: the frequency table for the locations of the balls. Note the names of the vector are the locations: 1.5, 2.5, ..., layers - 0.5.
The bean machine, also known as the quincunx or Galton box, is a device invented by Sir Francis Galton to demonstrate the law of error and the normal distribution.
When a ball falls through a layer, it can either go to the right or left side with the probability 0.5. At last the location of all the balls will show us the bell-shaped distribution.
Examples at https://yihui.org/animation/example/quincunx/