dYoN.Rd
The youngest of N infections, density function
dYoN(N, a, FoI_a, hhat = NULL, bday = 0, r = 1/200)
the number of infections
the age of a cohort
a cohort trace function
a local scaling parameter for the FoIs
the cohort birthday
the clearance rate of a simple infection
a numeric vector of length a + 1