Fit Recruitment Model with Maximum Likelihood

Fit recruitment model with Maximum Likelihood using Nimble Laplace Approximation.

bb_fit_recruitment_ml(
  data,
  adult_female_proportion = 0.65,
  sex_ratio = 0.5,
  min_random_year = 5,
  year_trend = FALSE,
  year_start = 4L,
  inits = NULL,
  quiet = FALSE
)

Arguments

data

The data.frame.

adult_female_proportion

A number between 0 and 1 of the expected proportion of adults that are female. If NULL, the proportion is estimated from the data (i.e., Cows ~ Binomial(adult_female_proportion, Cows + Bulls)) and a prior of dbeta(65, 35) is used. This prior can be changed via the priors argument.

sex_ratio

A number between 0 and 1 of the proportion of females at birth. This proportion is applied to yearlings.

min_random_year

A whole number of the minimum number of years required to fit year as a random effect (as opposed to a fixed effect).

year_trend

A flag indicating whether to fit a year trend effect. Year trend cannot be fit if there is also a fixed year effect (as opposed to random effect).

year_start

A whole number between 1 and 12 indicating the start of the caribou (i.e., biological) year. By default, April is set as the start of the caribou year.

inits

A named vector of the parameter initial values. Any missing values are assigned a default value of 0. If NULL, all parameters are assigned a default value of 0.

quiet

A flag indicating whether to suppress messages and progress bars.

Value

A list of the Nimble model object and Maximum Likelihood output with estimates and standard errors on the transformed scale.

Details

If the number of years is > min_random_year, a fixed-effects model is fit. Otherwise, a mixed-effects model is fit with random intercept for each year. If year_trend is TRUE and the number of years is > min_random_year, the model will be fit with year as a continuous effect (i.e. trend) and no fixed effect of year. If year_trend is TRUE and the number of years is <= min_random_year, the model will be fit with year as a continuous effect and a random intercept for each year.

The start month of the Caribou year can be adjusted with year_start.

See also

Other model: bb_fit_recruitment(), bb_fit_survival(), bb_fit_survival_ml()

Examples

if (interactive()) {
  fit <- bb_fit_recruitment_ml(bboudata::bbourecruit_a)
}