A Poisson model for attack rates as a function of the daily EIR.
# S3 method for class 'pois'
F_ar(eir, b, pars)
a numeric vector: attack rates for the population strata
This function computes the daily attack rates (\(\alpha\)), the fraction of a cohort that gets infected in a day, as a function of the daily EIR (\(E\)) under a Poisson model for the distribution of bites per person, and the probability of infection per infective bite (\(b\)): $$\alpha = 1 - e^{- b E}$$ The expression is equivalent to
ppois(0, b*eir, lower.tail=FALSE)
Related: F_foi & F_foi.pois & ar2eir.pois. Called from Exposure.dts