| 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:
mainparmsk1k2k3timesinitTo 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"
)