alogistic {primer}

Logistic growth with the Allee effect

Description

A function for continuous logistic growth with the Allee effect, for use with ode in the deSolve package.

Usage

alogistic(t, y, p)

Arguments

t

Time points for which N wll be returned.

y

N, population size

p

a vector of logistic growth (r, alpha) and Allee effect parameters (a, tau); a is the threshold population size.

Details

The user does not put these directly into this function, but rather uses codeode in the deSolve package. The function is based on the logistic growth equation

\frac{dN}{dt} = rN\left(1-\alpha N\right)\left(1 - \frac{a+\tau}{N+\tau}\right)

with a being the threshold population size.

Author(s)

Hank Stevens

References

Stevens. M.H.H. (2009) A Primer of Ecology with R. Use R! Series. Springer.

See Also

clogistic,dlogistic, thetalogistic, levins

Examples

library(deSolve)
p <- c(r=1,alpha=.01, a=10, tau=.1)
time <- 0:10
initialN <- 11
out <- ode(y=initialN, times=time,
             func=alogistic, parms=p)
plot(time, out[,-1], type='l')