Make a Function, \(F(a,d)\)

Construct a trace function to simulate exposure by age using make_F_t.

The function substitutes age for time: given a birthday, \(d\), age is \(a=t-d\). The function is a product of:

• \(\bar X\) — or avg the approximate mean value

• \(F_\omega(a)\) — a function describing the relative biting rate by age

• \(F_S(t)\) — a seasonal pattern function

• \(F_T(t)\) — a trend pattern function

• \(F_K(t)\) — a shock function $$F(a, d) = x \times \omega(a) \times F_S(t-d) \times F_T(t-d) \times F_K(t-d)$$

For convenience, \(d\) is an optional argument with a default value \(d=0\)

Usage

make_F_a(
  avg,
  age_par = makepar_F_c(1),
  season_par = makepar_F_c(1),
  trend_par = makepar_F_c(1),
  shock_par = makepar_F_c(1)
)

Arguments

avg

the function average

age_par

an F_obj for relative biting rate by age

season_par

an F_obj for the seasonal pattern (see seasonality)

trend_par

an F_obj for the trend (see trends)

shock_par

an F_obj for a perturbation (see shocks)

Value

a function