SIRf {primer} | R Documentation |
The S-I-R epidemilogical disease model with frequency dependent transmission, for use with ode
in the deSolve
package.
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>
S.P. Ellner and J. Guckenheimer. Dynamic Models in Biology. Princeton University Press, 2006.
W.O. Kermack and W.G. McCormick. A contribution to the mathematical theory of epidemics. Proceedings of the Royal Society, Series A, 115:700-721, 1927.
M.H.H. Stevens. 2009. A Primer of Ecology with R. Use R! Series. Springer.
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')