Calculates the feeding level \(f_i(w)\). The feeding level is the
proportion of its maximum intake rate at which the predator is actually
taking in fish. It is calculated from the encounter rate \(E_i\) and the
maximum intake rate \(h_i(w)\) as
$$f_i(w) = \frac{E_i(w)}{E_i(w)+h_i(w)}.$$
The encounter rate \(E_i\) is passed as an argument or calculated with
getEncounter. The maximum intake rate \(h_i(w)\) is
taken from the params object, and is set with
setIntakeMax.
As a consequence of the above expression for the feeding level,
\(1-f_i(w)\) is the proportion of the food available to it that the
predator actually consumes.
getFeedingLevel(object, n, n_pp, n_other, encounter, time_range, drop = FALSE)
| encounter | The encounter rate matrix (optional) of dimension no.
species x no. size bins. If not passed in, it is calculated internally
using |
|---|
If a MizerParams object is passed in, the function returns a two
dimensional array (predator species x predator size) based on the
abundances also passed in.
If a MizerSim object is passed in, the function returns a three
dimensional array (time step x predator species x predator size) with the
feeding level calculated at every time step in the simulation.
If drop = TRUE then the dimension of length 1 will be removed from
the returned array.
The feeding level is used in getEReproAndGrowth and in
getPredRate.
Other rate functions:
getEGrowth(),
getEReproAndGrowth(),
getERepro(),
getEncounter(),
getFMortGear(),
getFMort(),
getMort(),
getPlanktonMort(),
getPredMort(),
getPredRate(),
getRDD(),
getRDI(),
getRates(),
getStarvMort()
if (FALSE) { data(NS_species_params_gears) data(inter) params <- newMultispeciesParams(NS_species_params_gears, inter) # With constant fishing effort for all gears for 20 time steps sim <- project(params, t_max = 20, effort = 0.5) # Get the feeding level at one time step n <- sim@n[21,,] n_pp <- sim@n_pp[21,] fl <- getFeedingLevel(params,n,n_pp) # Get the feeding level at all saved time steps fl <- getFeedingLevel(sim) # Get the feeding level for time 15 - 20 fl <- getFeedingLevel(sim, time_range = c(15,20)) }