Project population — project

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: A numeric vector containing age-specific abundance at end of year t.
age0: A numeric vector of length one containing number of new recruits at end of year t.
nM: Numeric vector of instantaneous natural mortality.
fM: Numeric vector of instantaneous fishing mortality.
max_age: Numeric indicating 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
  
} # }