ecol.death.sim {animation}

A simulation of the death of two species with certain probabilities

Description

Suppose there are two plant species in a field: A and B. One of them will die at each time and a new plant will grow in the place where the old plant died; the species of the new plant depends on the proportions of two species: the larger the proportion is, the greater the probability for this species to come up will be.

Usage

ecol.death.sim(
  nr = 10,
  nc = 10,
  num.sp = c(50, 50),
  col.sp = c(1, 2),
  pch.sp = c(1, 2),
  col.die = 1,
  pch.die = 4,
  cex = 3,
  ...
)

Arguments

nr, nc

number of rows and columns of the field (plants grow on a nr x nc grid)

num.sp

number of two plants respectively

col.sp, pch.sp

colors and point symbols of the two species respectively

col.die, pch.die, cex

the color, point symbol and magnification to annotate the plant which dies (symbol default to be an ‘X’)

...

other arguments passed to plot to set up the plot

Value

a vector (factor) containing 1's and 2's, denoting the plants finally survived

Note

2 * ani.options('nmax') image frames will actually be produced.

Author(s)

Yihui Xie

References

This animation is motivated by a question raised from Jing Jiao, a student in biology, to show the evolution of two species.

The original post is in the forum of the “Capital of Statistics”: https://d.cosx.org/d/14093 (in Chinese)

Examples

oopt = ani.options(nmax = ifelse(interactive(), 50, 2), interval = 0.3)
par(ann = FALSE, mar = rep(0, 4))
ecol.death.sim()

## large scale simulation
ani.options(nmax = ifelse(interactive(), 1000, 2), interval = 0.02)
ecol.death.sim(col.sp = c(8, 2), pch.sp = c(20, 17))

ani.options(oopt)