Get energy rate available for growth

Calculates the energy rate \(g_i(w)\) (grams/year) available by species and size for growth after metabolism, movement and reproduction have been accounted for.

Usage

getEGrowth(
  params,
  n = initialN(params),
  n_pp = initialNResource(params),
  n_other = initialNOther(params),
  t = 0,
  ...
)

Arguments

params

A MizerParams object

n

A matrix of species abundances (species x size).

n_pp

A vector of the resource abundance by size

n_other

A list of abundances for other dynamical components of the ecosystem

t

The time for which to do the calculation (Not used by standard mizer rate functions but useful for extensions with time-dependent parameters.)

...

Unused

Value

An ArraySpeciesBySize object (species x size) with the somatic growth rates (grams/year).

Details

The growth rate is calculated as the difference between the energy available for reproduction and growth (obtainable with getEReproAndGrowth()) and the energy used for reproduction (obtainable with getERepro()), but is set to 0 if the result would be negative.

Your own growth rate function

By default getEGrowth() calls mizerEGrowth(). However you can replace this with your own alternative growth rate function. If your function is called "myEGrowth" then you register it in a MizerParams object params with

params <- setRateFunction(params, "EGrowth", "myEGrowth")

Your function will then be called instead of mizerEGrowth(), with the same arguments.

See also

getERepro(), getEReproAndGrowth()

Other rate functions: getDiffusion(), getERepro(), getEReproAndGrowth(), getEncounter(), getFMort(), getFMortGear(), getFeedingLevel(), getFlux(), getMort(), getPredMort(), getPredRate(), getRDD(), getRDI(), getRates(), getResourceMort()

Examples

# \donttest{
params <- NS_params
# Project with constant fishing effort for all gears for 20 time steps
sim <- project(params, t_max = 20, effort = 0.5)
# Get the energy at a particular time step
growth <- getEGrowth(params, n = N(sim)[15, , ], n_pp = NResource(sim)[15, ], t = 15)
# Growth rate at this time for Sprat of size 2g
growth["Sprat", "2"]
#> [1] 4.706336
# }