lv {simecol} | R Documentation |
simecol example: basic Lotka-Volterra predator prey-model.
data(lv)
An S4 object according to the odeModel
specification.
The object contains the following slots:
main
parms
k1
k2
k3
times
init
To see all details, please have a look into the implementation.
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
.
##============================================ ## 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" )