SIRf: The S-I-R Epidemilogical Disease Model with Frequency...
In primer: Functions and Data for the Book, a Primer of Ecology with R

Description Usage Arguments Details Value Author(s) References See Also Examples

The S-I-R epidemilogical disease model with frequency dependent transmission, for use with ode in the deSolve package.

1	SIRf(t, y, p)

`t`	times points for which values will be returned
`y`	the vector of disease states of hosts (S, I, R)
`p`	a vector of parameters

The user does not put these directly into this function, but rather uses ode in the deSolve package.

Returns of list of one component (required by ode).

Hank Stevens <HStevens@muohio.edu>

Ellner, S.P. and Guckenheimer, J. (2006) Dynamic Models in Biology, Princeton University Press.

Kermack, W.O. and McCormick, W.G. (1927) A contribution to the mathematical theory of epidemics. Proceedings of the Royal Society, Series A, 115, 700–721.

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

ross, SIRd, SIRbd, ode

R <- 0; S <- 1000;  I <- 1000; N <- S+I+R
parmsf <- c(B=1, g=1)
Months <- seq(0, 8, by=0.1)
outf <- ode(c(S,I,R), Months, SIRf, parmsf)
matplot(Months, outf[,-1], type='l', ylab="Prevalence (I/N)")
legend('right', legend=c('S','I','R'), lty=1:3, col=1:3, bty='n')