# lv: Lotka-Volterra Predator-Prey Model In simecol: Simulation of Ecological (and Other) Dynamic Systems

## Description

simecol example: basic Lotka-Volterra predator prey-model.

## Usage

 `1` ```data(lv) ```

## Format

An S4 object according to the `odeModel` specification. The object contains the following slots:

`main`

Lotka-Volterra equations for predator and prey.

`parms`

Vector with the named parameters of the model:

`k1`

growth rate of the prey population,

`k2`

encounter rate of predator and prey,

`k3`

death rate of the predator population.

`times`

Simulation time and integration interval.

`init`

Vector with start values for predator and prey.

## Details

To see all details, please have a look into the implementation.

## References

Lotka, A. J. 1925. Elements of physical biology. Williams and Wilkins, Baltimore.

Volterra, V. (1926). Variazionie fluttuazioni del numero d'individui in specie animali conviventi. Mem. Acad.Lincei, 2, 31-113.

`simecol-package`, `sim`, `parms`, `init`, `times`.

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28``` ```##============================================ ## Basic Usage: ## explore the example ##============================================ data(lv) print(lv) plot(sim(lv)) parms(lv) <- c(k1=0.5, k2=0.5, k3=0.5) plot(sim(lv)) ##============================================ ## Implementation: ## The code of the Lotka-Volterra-model ##============================================ lv <- new("odeModel", main = function (time, init, parms) { x <- init p <- parms dx1 <- p["k1"] * x[1] - p["k2"] * x[1] * x[2] dx2 <- - p["k3"] * x[2] + p["k2"] * x[1] * x[2] list(c(dx1, dx2)) }, parms = c(k1=0.2, k2=0.2, k3=0.2), times = c(from=0, to=100, by=0.5), init = c(prey=0.5, predator=1), solver = "rk4" ) ```

simecol documentation built on June 3, 2018, 5:07 p.m.