igp {primer} | R Documentation |
A Lotka-Volterra model of intraguild predation, after Holt and Polis (1997). For use with ode
in the deSolve
package.
igp(t, y, params)
t |
the time point for a realization of the integration. |
y |
the vector of populations, at each time t. |
params |
a vector or list containing the necessary parameters. |
Returns a list of length one which is the vector of the rates of increase (required by ode
).
Hank Stevens <HStevens@muohio.edu>
R.D. Holt and G.A Polis. A theoretical framework for intraguild predation. The American Naturalist, 149:745-764, 1997.
M.H.H. Stevens. A Primer of Ecology with R. Use R! Series. Springer, 2009.
library(deSolve) params <- c(bpb= 0.032, abp=10^-8, bpn=10^-5, anp=10^-4, mp=1, bnb=0.04, abn=10^-8, mn=1, r=1, abb=10^-9.5) t=seq(0, 60, by=.1) N.init <- c(B = 10^9, N = 10^4, P = 10^3) igp.out <- ode(N.init, t, igp, params) matplot(t, log10(igp.out[,-1]+1), type="l", ylab="log(Abundance)") legend('right', c("B", "N", "P"), lty=1:3, col=1:3, lwd=2, bty="n")