verhulst {pomp} | R Documentation |
The Verhulst-Pearl (logistic) model of population growth.
verhulst(n_0 = 10000, K = 10000, r = 0.9, sigma = 0.4, tau = 0.1, dt = 0.01)
n_0 |
initial condition |
K |
carrying capacity |
r |
intrinsic growth rate |
sigma |
environmental process noise s.d. |
tau |
measurement error s.d. |
dt |
Euler time-step |
A stochastic version of the Verhulst-Pearl logistic model. This evolves in continuous time, according to the stochastic differential equation
dn = r n (1-n/K) dt + sigma n dW.
Numerically, we simulate the stochastic dynamics using an Euler approximation.
The measurements are assumed to be log-normally distributed.
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’.
Other pomp examples: blowflies
,
dacca
, ebola
,
gompertz
, measles
,
ou2
, ricker
,
rw2
, sir_models
verhulst() -> po plot(po) plot(simulate(po)) pfilter(po,Np=1000) -> pf logLik(pf) spy(po)