mizer (version 3.0.0)

steadySingleSpecies: Set initial abundances to solution of steady-state equation with current rates

Description

This first calculates growth and death rates that arise from the current initial abundances. Then it solves the steady-state equation with these growth and death rates and the current abundance at the smallest size. It sets the initial abundances of the selected species to this solution.

Usage

steadySingleSpecies(
  params,
  species = NULL,
  keep = c("egg", "biomass", "number")
)

Value

A MizerParams object in which the initial abundances of the selected species are changed to their single-species steady state abundances.

Arguments

params

A MizerParams object

species

The species to be selected. Optional. By default all target species are selected. A vector of species names, or a numeric vector with the species indices, or a logical vector indicating for each species whether it is to be selected (TRUE) or not.

keep

A string determining which quantity is to be kept constant. The choices are "egg" which keeps the egg density constant, "biomass" which keeps the total biomass of the species constant and "number" which keeps the total number of individuals constant.

Details

The function only changes the initial abundances. It does not adjust the reproduction parameters or any other parameters. Therefore the result of applying this function is of course not a steady state, because after changing the abundances of the selected species the growth, death and reproduction rates will have changed.

If the keep argument is supplied, the solution for the selected species are rescaled to keep the specified quantity at the value they had before calling this function.

Examples

# Set initial abundance of Cod to its single-species steady state
params <- steadySingleSpecies(NS_params, species = "Cod")