Project population

Function used to project population forward one time step using vector multiplication.

Usage

project_pop(x, age0, nM, fM, max_age, species = c("AMS", "ALE", "BBH"))

Arguments

x

An numeric vector containing age-specific abundance at end of year t.

age0

A vector of length one containing number of new recruits at end of year t.

nM

Instantaneous natural mortality.

fM

Instantaneous fishing mortality.

max_age

Maximum age of spawning fish.

species

Species for which population dynamics will be simulated. Choices include American shad ("AMS"), alewife ("ALE"), and blueback herring ("BBH").

Value

A numeric vector of age-structured abundance in time t + 1

Examples

# Example usage
if (FALSE) { # \dontrun{
  
 # Simulate a population
 n_init = 1e5  
 max_age = 13
 nM = .505
 fM = 0
 pop = make_pop(max_age=max_age, nM=nM, fM=fM, n_init=n_init)
 
 # Project one time-step without reproduction
 new_pop = project_pop(x=pop, age0=1e5, nM=.505, fM=0, max_age)
 
 # Difference should be about zero 
 # because age0 - n_init
 new_pop - pop
  
} # }