mizer (version 1.0.1)

getFeedingLevel: Get feeding level

Description

Calculates the feeding level \(f_i(w)\) as a by predator size based on food availability, search volume and maximum intake. The feeding level is the proportion of the encountered food that is actually consumed.This method is used by the project method for performing simulations.

Usage

getFeedingLevel(object, n, n_pp, phi_prey, ...)
# S4 method for MizerParams,matrix,numeric,matrix
getFeedingLevel(object, n,
  n_pp, phi_prey, ...)
# S4 method for MizerParams,matrix,numeric,missing
getFeedingLevel(object, n,
  n_pp, phi_prey, ...)
# S4 method for MizerSim,missing,missing,missing
getFeedingLevel(object,
  time_range = dimnames(object@n)$time, drop = FALSE, ...)

Arguments

object

A MizerParams or MizerSim object

n

A matrix of species abundance (species x size). Only used if object argument is of type MizerParams.

n_pp

A vector of the background abundance by size. Only used if object argument is of type MizerParams.

phi_prey

The PhiPrey matrix (optional) of dimension no. species x no. size bins. If not passed in, it is calculated internally using the getPhiPrey method. Only used if object argument is of type MizerParams.

...

Other arguments (currently unused).

time_range

Subset the returned fishing mortalities by time. The time range is either a vector of values, a vector of min and max time, or a single value. Default is the whole time range. Only used if the object argument is of type MizerSim.

drop

should extra dimensions of length 1 in the output be dropped, simplifying the output. Defaults to TRUE.

See Also

getPhiPrey

Examples

# NOT RUN {
data(NS_species_params_gears)
data(inter)
params <- MizerParams(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))
# }