Examples of conditional dynamical growth models (maps)

Conditional Autocatlytic Growth: Iterating differential equations (maps)

growth_ac_cond(
  Y0 = 0.01,
  r = 0.1,
  k = 2,
  cond = cbind.data.frame(Y = 0.2, par = "r", val = 2),
  N = 100
)

Arguments

Y0

Initial value

r

Growth rate parameter

k

Carrying capacity

cond

Conditional rules passed as a data.frame of the form: cbind.data.frame(Y = ..., par = ..., val = ...)

N

Length of the time series

See also

Other autocatalytic growth functions: growth_ac()

Author

Fred Hasselman

Examples

# Plot with the default settings
library(lattice)
xyplot(growth_ac_cond())


# The function can take a set of conditional rules
# and apply them sequentially during the iterations.
# The conditional rules are passed as a `data.frame`

(cond <- cbind.data.frame(Y = c(0.2, 0.6), par = c("r", "r"), val = c(0.5, 0.1)))
#>     Y par val
#> 1 0.2   r 0.5
#> 2 0.6   r 0.1
xyplot(growth_ac_cond(cond=cond))


# Combine a change of `r` and a change of `k`

(cond <- cbind.data.frame(Y = c(0.2, 1.99), par = c("r", "k"), val = c(0.5, 3)))
#>      Y par val
#> 1 0.20   r 0.5
#> 2 1.99   k 3.0
xyplot(growth_ac_cond(cond=cond))


# A fantasy growth process

cond <- cbind.data.frame(Y = c(0.1, 1.99, 1.999, 2.5, 2.9),
par = c("r", "k", "r", "r","k"),
val = c(0.3, 3, 0.9, 0.1, 1.3))

xyplot(growth_ac_cond(cond=cond))