Quickstart

This vignette illustrates the basic use of demovuln.

library(demovuln)

We define a simple two-stage projection matrix. Columns are source stages at time t, and rows are destination stages at time t + 1.

A <- matrix(
  c(0.0, 0.4,
    2.0, 0.7),
  nrow = 2,
  byrow = FALSE
)

A
#>      [,1] [,2]
#> [1,]  0.0  2.0
#> [2,]  0.4  0.7

model <- matrix_population_model(
  A,
  adult_stages = 2,
  juvenile_stages = 1
)

We simulate a perturbation affecting adult survival.

sim <- simulate_dynamics(
  model,
  target = "adult_survival",
  magnitude = 0.25,
  duration = 1,
  period = 3,
  t_max = 50,
  recovery_steps = 10
)

sim$reduction
#> [1] 95.95533

plot(
  sim$baseline_abundance,
  type = "l",
  lwd = 2,
  xlab = "Time step",
  ylab = "Relative population size",
  ylim = range(c(sim$baseline_abundance, sim$abundance))
)

lines(sim$abundance, lwd = 2, lty = 2)

legend(
  "topright",
  legend = c("Baseline", "Perturbed"),
  lty = c(1, 2),
  lwd = 2,
  bty = "n"
)