verhulst {pomp} | R Documentation |
Verhulst-Pearl model
Description
The Verhulst-Pearl (logistic) model of population growth.
Usage
verhulst(n_0 = 10000, K = 10000, r = 0.9, sigma = 0.4, tau = 0.1, dt = 0.01)
Arguments
n_0 |
initial condition |
K |
carrying capacity |
r |
intrinsic growth rate |
sigma |
environmental process noise s.d. |
tau |
measurement error s.d. |
dt |
Euler timestep |
Details
A stochastic version of the Verhulst-Pearl logistic model. This evolves in continuous time, according to the stochastic differential equation
Numerically, we simulate the stochastic dynamics using an Euler approximation.
The measurements are assumed to be log-normally distributed:
Value
A ‘pomp’ object containing the model and simulated data. The following basic components are included in the ‘pomp’ object: ‘rinit’, ‘rprocess’, ‘rmeasure’, ‘dmeasure’, and ‘skeleton’.
See Also
More examples provided with pomp:
blowflies
,
childhood_disease_data
,
compartmental_models
,
dacca()
,
ebola
,
gompertz()
,
ou2()
,
pomp_examples
,
ricker()
,
rw2()
Examples
# takes too long for R CMD check
verhulst() -> po
plot(po)
plot(simulate(po))
pfilter(po,Np=1000) -> pf
logLik(pf)
spy(po)