MLZ (version 0.1.5)

modal_length: Modal length from length data

Description

Calculates the annual modal length from the length data, which can be used to select Lc. Note: Modal length can change over time for many reasons, including a change in mortality (Hordyk et al. 2015), recruitment, or selectivity (Huynh et al. 2017).

Usage

modal_length(MLZ_data, length.slot = c("Len_df", "Len_matrix"),
  breaks = NULL, figure = TRUE)

Value

A data frame of plotted values.

Arguments

MLZ_data

An object of class MLZ_data.

length.slot

Name of slot in MLZ_data from which to calculate modal lengths, either: Len_df or Len_matrix. Only used if there are data in both slots.

breaks

Only used for Len_df. An optional vector for breaks for bin_length.

figure

If TRUE, a plot is also drawn.

Details

Length frequency matrix from Len_df are created by using hist function.

References

Hordyk, A. Ono, K., Sainsbury, K., Loneragan, N., and Prince, J. 2015. Some explorations of the life history ratios to describe length composition, spawning-per-recruit, and the spawning potential ratio. ICES Journal of Marine Science 72:204-216.

Huynh, Q.C, Gedamke, T., Hoenig, J.M, and Porch C. 2017. Multispecies Extensions to a Nonequilibrium Length-Based Mortality Estimator. Marine and Coastal Fisheries 9:68-78.

Examples

if (FALSE) {
data(Nephrops)
modal_length(Nephrops)

data(SilkSnapper)
new.dataset <- new("MLZ_data", Year = 1983:2013, Len_df = SilkSnapper)
modal_length(new.dataset)
modal_length(new.dataset, breaks = seq(80, 830, 10))
}