SIR {primer} | R Documentation |
The S-I-R epidemilogical disease model, for use with ode
in the deSolve
package.
SIR(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.
N <- 10^3; I <- R <- 1; S <- N - I - R parms <- c(B=.01, g=4) months <- seq(0, 3, by=0.01) require(deSolve) SIR.out <- data.frame( ode(c(S,I,R), months, SIR, parms) ) matplot(months, SIR.out[,-1], type='l') legend('right', c('R', 'I', 'S'), lty=3:1, col=3:1, bty='n')